MACK DTCs Service Manual (2024)

MACK DTCs Service Manual (1)

Service Manual

Trucks

Group 28

Engine Control Module (ECM), Diagnostic Trouble Code

(DTC), Guide

2010 Emissions

MRU, LEU

PV776-88969578

Foreword

The descriptions and service procedures contained in this manual are based on designs and methods studies carried out up to April 2010.

The products are under continuous development. Vehicles and components produced after the above date may therefore have different specifications and repair methods. When this is believed to have a significant bearing on this manual, supplementary service bulletins will be issued to cover the changes.

The new edition of this manual will update the changes.

In service procedures where the title incorporates an operation number, this is a reference to a Labor Code (Standard Time).

Service procedures which do not include an operation number in the title are for general information and no reference is made to a Labor Code (Standard Time).

Each section of this manual contains specific safety information and warnings which must be reviewed before performing any procedure. If a printed copy of a procedure is made, be sure to also make a printed copy of the safety information and warnings that relate to that procedure. The following levels of observations, cautions and warnings are used in this Service Documentation:

Note: Indicates a procedure, practice, or condition that must be followed in order to have the vehicle or component function in the manner intended.

Caution: Indicates an unsafe practice where damage to the product could occur.

Warning: Indicates an unsafe practice where personal injury or severe damage to the product could occur.

Danger: Indicates an unsafe practice where serious personal injury or death could occur.

Mack Trucks, Inc.

Greensboro, NC USA

Order number: PV776-88969578

Repl:

©2010 Mack Trucks, Inc., Greensboro, NC USA

All rights reserved. No part of this publication may be reproduced, stored in retrieval system, or transmitted in any forms by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of Mack Trucks, Inc.

USA41614

Contents

Troubleshooting ..........................................................................................................................

3

Engine Control Module (ECM) Diagnostic Trouble Codes (DTCs) .....................................................

3

1

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Troubleshooting

Engine Control Module (ECM) Diagnostic Trouble Codes (DTCs)

The manufacturer scan tool is the preferred tool for performing diagnostic work. Contact your local dealer for more information or visit “www.premiumtechtool.com”.

Note: Theuseofascantoolisnecessarytoperformdiagnostic work as well as clearing of any diagnostic trouble codes (DTCs). DTC(s) can no longer be cleared using the vehicles instrument cluster digital display and stalk switch control.

System Overview

Six electronic control units (ECUs) are used; the engine control module (ECM), instrument control module (ICM), Vehicle Electronic Control Unit (VECU), transmission control module (TCM), the gear selector control module (GSCM) and the aftertreatment control module (ACM). Together, these modules operate and communicate through the SAE J1939 data links to control a variety of engine and vehicle cab functions. The ECM controls such things as fuel timing and delivery, fan operation, engine protection functions, engine brake operation, the exhaust gas recirculation (EGR) valve and the turbocharger nozzle. The VECU controls cruise control functions, accessory relay controls and idle shutdown functions. The ICM primarily displays operational parameters and communicates these to the other ECUs. All have the capability to communicate over the SAE J1587 data link primarily for programming, diagnostics and data reporting.

In addition to their control functions, the modules have on board diagnostic (OBD) capabilities. The OBD is designed to detect faults or abnormal conditions that are not within normal operating parameters. When the system detects a fault or abnormal condition, the fault will be logged in one or both of the modules’ memory, the vehicle operator will be advised that a fault has occurred by illumination a malfunction indicator lamp (MIL) and a message in the driver information display, if equipped. The module may initiate the engine shutdown procedure if the system determines that the fault could damage the engine.

In some situations when a fault is detected, the system will enter a "derate" mode. The derate mode allows continued vehicle operation but the system may substitute a sensor or signal value that may result in reduced performance. In some instances, the system will continue to function but

engine power may be limited to protect the engine and vehicle. Diagnostic trouble codes (DTCs) logged in the system memory can later be read, to aid in diagnosing the problem using a diagnostic computer or through the instrument cluster display, if equipped. When diagnosing an intermittent DTC or condition, it may be necessary to use a scan tool connected to the Serial Communication Port.

The use of a scan tool is necessary to perform diagnostic work as well as clearing of any diagnostic trouble codes (DTCs). DTC(s) can no longer be cleared using the vehicles instrument cluster digital display and stalk switch control. Additional data and diagnostic tests are available when a scan tool is connected to the Serial Communication Port.

For diagnostic software, contact your local dealer.

The ECM is a microprocessor based controller programmed to perform fuel injection quantity and timing control, diagnostic fault logging, and to broadcast data to other ECUs. The fuel quantity and injection timing to each cylinder is precisely controlled to obtain optimal fuel economy and reduced exhaust emissions in all driving situations.

The ECM controls the operation of the injectors, engine brake solenoid, EGR valve, turbocharger nozzle position, and cooling fan clutch based on inputs from many sensors and information received over the data links from other ECUs.

The VECU and ECM are dependent on each other to perform their specific control functions. In addition to switch and sensor data, the broadcast of data between modules also includes various calculations and conclusions that each module has developed, based on the input information it has received.

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System Electronic Control Unit (ECU) Overview

The engine control module (ECM) monitors and models (using physical principles) engine parameters to monitor the engine system’s performance in real time. This is performed to aid the ECM with its self diagnostic capabilities. Many sensors are used for input to the emission control system.

The system contains the following “emission critical” ECUs that are monitored;

Engine Control Module (ECM)

Vehicle Electronic Control Unit (VECU)

Aftertreatment Control Module (ACM)

Aftertreatment Nitrogen Oxides (NOx) Sensors

Engine Variable Geometry Turbocharger (VGT) Smart Remote Actuator (SRA)

These ECUs all communicate with the ECM via data links. The VECU communicates across the SAE J1939 (CAN1) data link while the others use the SAE J1939-7 (CAN2) data link.

The OBD systems use SAE J1939 data link protocol for communication with scan tools but, MACK trucks still are capable of communicating via the SAE J1587 data link for diagnostics. The use of a scan tool is necessary to perform diagnostic work as well as clearing of any diagnostic trouble codes (DTCs). DTC(s) can no longer be cleared using the vehicles instrument cluster digital display and stalk switch control.

There are other ECUs such as the Instrument Control Module (ICM), Transmission Control Module (TCM) and Anti-lock Brake System (ABS) Module that provide data to the emission control system or the diagnostic system but are not “emission critical”.

Malfunction Indicator Lamp (MIL), Description and Location

A MIL located in the instrument cluster. This amber colored lamp is used to inform the driver that a “emission critical” malfunction signal has occurred.

W2036007

SAE J1939 Data Link Communication

The electronic control units (ECUs) that communicate on the SAE J1939 data link, communicate according to the SAE J1587 standard. The diagnostic trouble codes (DTCs) set by the ECUs contain information that is described by the following abbreviations.

SA

Source Address:

Identification of a control module.

SPN

Suspect Parameter Number:

Identification of a parameter (value).

FMI

Failure Mode Identifier:

Identification of fault types.

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SAE J1939 FMI Table

FMI

SAE Text

Data valid but above normal operational range - Most severe level

1

Data valid but below normal operational range - Most severe level

2

Data erratic, intermittent or incorrect

3

Voltage above normal, or shorted to high source

4

Voltage below normal, or shorted to low source

5

Current below normal or open circuit

6

Current above normal or grounded circuit

7

Mechanical system not responding or out of adjustment

8

Abnormal frequency or pulse width or period

9

Abnormal update rate

10

Abnormal rate of change

11

Root cause not known

12

Bad intelligent device or component

13

Out of calibration

14

Special instructions

15

Data valid but above normal operating range - Least severe level

16

Data valid but above normal operating range - Moderately severe level

17

Data valid but below normal operating range - Least severe level

18

Data valid but below normal operating range - Moderately severe level

19

Received network data in error

20

Reserved for SAE assignment

21

Reserved for SAE assignment

22

Reserved for SAE assignment

23

Reserved for SAE assignment

24

Reserved for SAE assignment

25

Reserved for SAE assignment

26

Reserved for SAE assignment

27

Reserved for SAE assignment

28

Reserved for SAE assignment

29

Reserved for SAE assignment

30

Reserved for SAE assignment

31

Condition exists

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SAE J1587 Data Link Communication

The electronic control units (ECUs) also communicate on the SAE J1587 data link. These ECUs communicate according to the SAE J1587 standard. The standard has been extended with MACK’s supplement (PPID, PSID). The diagnostic trouble codes (DTCs) set by the ECUs contain information that is described by the following abbreviations.

MID

Message Identification Description:

Identification of a control module.

PID

Parameter Identification Description:

Identification of a parameter (value).

PPID

Proprietary Parameter Identification

Description Mack:

Unique identification of a parameter (value).

SID

Subsystem Identification Description:

Identification of a component.

PSID

Proprietary Subsystem Identification

Description Mack:

Unique identification of a component.

FMI

Failure Mode Identifier:

Identification of fault types.

SAE J1587 FMI Table

FMI

SAE Text

Data valid, but above the normal working range

1

Data valid, but below the normal working range

2

Intermittent or incorrect data

3

Abnormally high voltage or short circuit to higher voltage

4

Abnormally low voltage or short circuit to lower voltage

5

Abnormally low current or open circuit

6

Abnormally high current or short circuit to ground

7

Incorrect response from a mechanical system

8

Abnormal frequency

9

Abnormal update rate

10

Abnormally strong vibrations

11

Non-identifiable fault

12

Faulty module or component

13

Calibration values outside limits

14

Special instructions

15

Reserved for future use

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Diagnostic Trouble Code (DTC) Content

SPN 0–500

“ECM SPN 84, Wheel-Based Vehicle Speed – MID 128 PID 84”, page 14

“ECM SPN 91, Accelerator Pedal Position 1 – MID 128 PID 91”, page 14

“ECM SPN 94, Engine Fuel Delivery Pressure – MID 128 PID 94”, page 14

“ECM SPN 97, Water in Fuel Indicator – MID 128 PID 97”, page 15

“ECM SPN 98, Engine Oil Level – MID 128 PID 98”, page 16

“ECM SPN 100, Engine Oil Pressure – MID 128 PID 100”, page 17

“ECM SPN 102, Engine Intake Manifold 1 Pressure – MID 128 PID 102”, page 17

“ECM SPN 103, Engine Turbocharger 1 Speed – MID 128 PID 103”, page 18

“ECM SPN 105, Engine Intake Manifold 1 Temperature – MID 128 PID 105”, page 19

“ECM SPN 108, Barometric Pressure – MID 128 PID 108”, page 20

“ECM SPN 110, Engine Coolant Temperature – MID 128 PID 110”, page 20

“ECM SPN 111, Engine Coolant Level – MID 128 PID 111”, page 21

“ECM SPN 153, Engine High Resolution Crankcase Pressure – MID 128 PID 153/PSID 23”, page 22

“ECM SPN 158, Keyswitch Battery Potential – MID 128 PID 158/PSID 124”, page 23

“ECM SPN 171, Ambient Air Temperature – MID 128 PID 171”, page 23

“ECM SPN 173, Engine Exhaust Gas Temperature (EGT) – MID 128 PID 173 ”, page 24

“ECM SPN 175, Engine Oil Temperature 1 – MID 128 PID 175”, page 25

“ECM SPN 177, Transmission Oil Temperature – MID 128 PID 177”, page 26

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“ECM SPN 188, Engine Speed At Idle, Point 1 (Engine Configurations) – MID 128 PID 188”, page 26

“ECM SPN 190, Engine Speed – MID 128 PID 190”, page 27

“ECM SPN 228, Speed Sensor Calibration – MID 128 PID 228”, page 27

“ECM SPN 237, Vehicle Identification Number – MID 128 PSID 161/162”, page 27

“ECM SPN 245, Total Vehicle Distance – MID 128 PID 245”, page 28

“ECM SPN 251, Time – MID 128 PID 251”, page 28

“ECM SPN 252, Date – MID 128 PID 252”, page 29

“ECM SPN 411, Engine Exhaust Gas Recirculation Differential Pressure – MID 128 PID 411”, page 29

“ECM SPN 412, Engine Exhaust Gas Recirculation Temperature – MID 128 PID 412”, page 30

SPN 500–999

“ECM SPN 558, Accelerator Pedal 1 Idle Validation Switch

– MID 128 SID 230”, page 31

“ECM SPN 626, Intake Air Heater (IAH) Relay – MID 128 PID 45”, page 32

“ECM SPN 628, Program Memory – MID 128 SID 240”, page 32

“ECM SPN 629, Electronic Control Unit (ECU) 1 – MID 128 SID 254”, page 33

“ECM SPN 630, Calibration Memory – MID 128 SID 253”, page 33

“ECM SPN 631, Calibration Module – MID 128 PSID 77/PSID 124”, page 34

“ECM SPN 633, Engine Fuel Actuator 1 Control Command

– MID 128 SID 18”, page 34

“ECM SPN 636, Camshaft Position Sensor (CMP) – MID 128 SID 21”, page 35

“ECM SPN 637, Crankshaft Position Sensor (CKP) – MID 128 SID 22”, page 36

“ECM SPN 639, SAE J1939 Data Link 1 – MID 128 SID 231”, page 37

“ECM SPN 641, Engine Variable Geometry Turbocharger (VGT) Actuator 1 – MID 128 SID 27”, page 37

“ECM SPN 642, Engine Variable Geometry Turbocharger (VGT) Actuator 2 – MID 128 PPID 89”, page 38

“ECM SPN 647, Engine Fan Clutch Output Device Driver – MID 128 SID 33”, page 38

“ECM SPN 651, Engine Injector Cylinder 1 – MID 128 SID 1”, page 39

“ECM SPN 652, Engine Injector Cylinder 2 – MID 128 SID 2”, page 40

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“ECM SPN 653, Engine Injector Cylinder 3 – MID 128 SID 3”, page 40

“ECM SPN 654, Engine Injector Cylinder 4 – MID 128 SID 4”, page 41

“ECM SPN 655, Engine Injector Cylinder 5 – MID 128 SID 5”, page 42

“ECM SPN 656, Engine Injector Cylinder 6 – MID 128 SID 6”, page 43

“ECM SPN 677, Engine Starter Motor Relay – MID 128 SID 39”, page 43

“ECM SPN 729, Intake Air Heater (IAH) 1 – MID 128 SID 70”, page 44

“ECM SPN 730, Intake Air Heater (IAH) 2 – MID 128 SID 71”, page 44

“ECM SPN 975, Estimated Percent Fan Speed – (MID 128 PID 26)”, page 45

SPN 1000–1999

“ECM SPN 1072, Engine Compression Brake Output #1 – MID 128 PPID 122”, page 46

“ECM SPN 1127, Engine Turbocharger Intake Manifold Pressure (IMP) – MID 128 PSID 98”, page 47

“ECM SPN 1136, Engine Control Module (ECM) Temperature – MID 128 PPID 55”, page 48

“ECM SPN 1198, Anti–theft Random Number – MID 128 PID 224”, page 48

“ECM SPN 1231, SAE J1939 Data Link 2 – MID 128 PSID 229/232”, page 49

“ECM SPN 1265, Engine Piston Cooling Oil Pressure Actuator – MID 128 SID 85”, page 49

“ECM SPN 1322, Engine Misfire for Multiple Cylinders – MID 128 PSID 27”, page 50

“ECM SPN 1659, Engine Coolant System Thermostat – MID 128 PSID 109”, page 50

“ECM SPN 1675, Engine Starter Mode – MID 128 SID 39”, page 50

“ECM SPN 1677, Aftertreatment DPF Auxiliary Heater Mode – MID 128 PSID 25”, page 51

“ECM SPN 1761, Aftertreatment Diesel Exhaust Fluid (DEF) Tank Level – PPID 278”, page 51

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SPN 2000–2999

“ECM SPN 2003, Transmission Control Module (TCM) Status – MID 128 PSID 205”, page 52

“ECM SPN 2017, Cruise Control Status – MID 128 PID 85”, page 52

“ECM SPN 2029, Invalid or Missing Data from Vehicle ECU

– MID 128 PSID 201”, page 52

“ECM SPN 2629, Engine Turbocharger Compressor Outlet Temperature – MID 128 PID 404”, page 53

“ECM SPN 2659, Engine Exhaust Gas Recirculation (EGR) Mass Flow Rate – MID 128 PPID 35”, page 53

“ECM SPN 2791, Engine Exhaust Gas Recirculation (EGR) Valve Control – MID 128 SID 146”, page 54

“ECM SPN 2836, Battery Potential/Switched Voltage – MID 128 PSID 49”, page 54

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“ECM SPN 3491, Aftertreatment Diesel Particulate Filter (DPF) Atomization Air Actuator – MID 128 PSID 59”, page 70

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Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

SPN 3000–3999

“ECM SPN 3031, Aftertreatment Diesel Exhaust Fluid (DEF) Tank Temperature – MID 128 PPID 274”, page 55

“ECM SPN 3064, Aftertreatment DPF System Monitor – MID 128 PPID 326”, page 55

“ECM SPN 3216, Aftertreatment Intake NOx – MID 128 PPID 348”, page 56

“ECM SPN 3226, Aftertreatment Outlet NOx – MID 128 PPID 270/ PSID 90”, page 56

“ECM SPN 3245, Aftertreatment DPF Outlet Temperature – MID 128 PPID 436”, page 57

“ECM SPN 3249, Aftertreatment DPF Intake Temperature

MID 128 PPID 387”, page 58

“ECM SPN 3250, Aftertreatment Diesel Particulate Filter (DPF) Intermediate Gas Temperature – MID 128 PPID 440/ PSID 22”, page 59

“ECM SPN 3251, Aftertreatment DPF Differential Pressure

MID 128 PID 81”, page 60

“ECM SPN 3363, Aftertreatment Diesel Exhaust Fluid (DEF) Tank Heater – MID 128 PSID 75”, page 61

“ECM SPN 3471, Aftertreatment Fuel Pressure Control Actuator/ MP8 Engine– MID 128 PPID 328”, page 61

“ECM SPN 3471, Aftertreatment Fuel Pressure Control Actuator/ MP7 Engine – MID 128 PSID 111”, page 62

“ECM SPN 3472, Aftertreatment Diesel Particulate Filter (DPF) Air Pressure Control Actuator– MID 128 PSID 58”, page 63

“ECM SPN 3473, Aftertreatment Failed to Ignite – MID 128 PSID 22”, page 64

“ECM SPN 3480, Aftertreatment Diesel Particulate Filter (DPF) Fuel Pressure/ MP8 Engine – MID 128 PPID 437/PSID 108”, page 64

“ECM SPN 3480, Aftertreatment Diesel Particulate Filter (DPF) Fuel Pressure/ MP7 Engine – MID 128 PPID 437”, page 65

“ECM SPN 3482, Aftertreatment Diesel Particulate Filter (DPF) Fuel Shutoff Valve – MID 128 PPID 328”, page 66

“ECM SPN 3483, Aftertreatment Regeneration Status – MID 128 PSID 47”, page 66

“ECM SPN 3484, Aftertreatment Ignition – MID 128 PSID 110/PSID 127”, page 67

“ECM SPN 3485, Aftertreatment Diesel Particulate Filter (DPF) Atomization Air Pressure – MID 128 PPID 277”, page 68

“ECM SPN 3489, Aftertreatment Air Enable Actuator – MID 128 PSID 122”, page 69

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“ECM SPN 3509, Sensor Supply Voltage 1 – MID 128 SID 232”, page 71

“ECM SPN 3510, Sensor Supply Voltage 2 – MID 128 SID 211”, page 71

“ECM SPN 3511, Sensor Supply Voltage 3 – MID 128 PSID 113”, page 72

“ECM SPN 3512, Sensor Supply Voltage 4 – MID 128 PSID 126”, page 72

“ECM SPN 3522, Aftertreatment Total Fuel Used – MID 128 PSID 91”, page 72

“ECM SPN 3556, Aftertreatment Hydrocarbon Doser/ MP8 Engine – MID 128 PPID 329”, page 73

“ECM SPN 3556, Aftertreatment Hydrocarbon Doser/ MP7 Engine – MID 128 PPID 329”, page 74

“ECM SPN 3597, Aftertreatment Diesel Particulate Filter (DPF) Regeneration too Frequent – MID 128 PSID 119”, page 74

“ECM SPN 3675, Engine Turbocharger Compressor Bypass Valve Position – MID 128 PPID 330”, page 75

“ECM SPN 3695, Aftertreatment Diesel Particulate Filter (DPF) Switch/MP8 Engine – MID 128 PSID 114”, page 76

“ECM SPN 3720, Aftertreatment DPF Ash Load Percent – MID 128 PPID 337”, page 76

“ECM SPN 3936, Aftertreatment DPF System – MID 128 PSID 28”, page 77

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SPN 4000–5500

“ECM SPN 4094, NOx Limits Exceeded Due to Insufficient Diesel Exhaust Fluid (DEF) Quality – MID 128 PSID 90”, page 77

“ECM SPN 4095, NOx Limits Exceeded Due to Interrupted Diesel Exhaust Fluid (DEF) Dosing – MID 128 PSID 90”, page 77

“ECM SPN 4334, Afterteatment Diesel Exhaust Fluid (DEF) Dosing Absolute Pressure – MID 128 PPID 273”, page 78

“ECM SPN 4339, Aftertreatment SCR Feedback Control Status – MID 128 PSID 90”, page 78

“ECM SPN 4354, Aftertreatment Diesel Exhaust Fluid (DEF) Line Heater 1 – MID 128 PSID 103”, page 79

“ECM SPN 4356, Aftertreatment Diesel Exhaust Fluid (DEF) Line Heater 3 – MID 128 PSID 102”, page 79

“ECM SPN 4374, Aftertreatment Diesel Exhaust Fluid (DEF) Pump Motor Speed – MID 128 PSID 87”, page 79

“ECM SPN 4375, Aftertreatment Diesel Exhaust Fluid Pump (DEF) Drive Percentage – MID 128 PSID 121”, page 80

“ECM SPN 4376, Aftertreatment Diesel Exhaust Fluid (DEF) Return Valve – MID 128 PSID 105”, page 81

“ECM SPN 4752, Engine Exhaust Gas Recirculation (EGR) Cooler Efficiency – MID 128 SID 282”, page 81

“ECM SPN 4811, Engine Piston Cooling Oil Pressure – MID 128 PPID 8”, page 81

“ECM SPN 4813, Engine Oil Thermostat Bypass Valve Opening – MID 128 PSID 72”, page 82

“ECM SPN 4815, Engine Cooling Fan Thermal Switch Position – MID 128 PPID 333”, page 82

“ECM SPN 5246, Aftertreatment SCR Operator Inducement Severity – MID 128 PSID 46”, page 83

“ECM SPN 5285, Charge Air Cooler (CAC) Temperature – MID 128 PID 52”, page 84

“ECM SPN 5298, Aftertreatment Diesel Oxidation Catalyst (DOC) Conversion Efficiency – MID 128 PSID 99”, page 84

“ECM SPN 5392, Aftertreatment Diesel Exhaust Fluid (DEF) Dosing Valve Loss of Prime – MID 128 PSID 121”, page 85

“ECM SPN 5394, Aftertreatment Diesel Exhaust Fluid (DEF) Dosing Valve – MID 128 PSID 89”, page 85

“ECM SPN 5394, Aftertreatment Diesel Exhaust Fluid (DEF) Dosing Valve – MID 128 PSID 90”, page 86

“ECM SPN 5485, Aftertreatment Diesel Exhaust Fluid (DEF) Pump Orifice – MID 128 PSID 121”, page 86

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Codes (DTCs)

ECM SPN 84, Wheel-Based Vehicle Speed – MID 128 PID 84

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 9

Abnormal update

Missing signal

Engine derate

SAE J1587 data link vehicle speed

rate

from VECU

message does not exist, (VECU error)

VECU

FMI 10

Abnormal rate of

Vehicle speed

MIL illuminated

Vehicle speed sensor (VSS)

change

deemed

(13L engine only)

VECU

inaccurate by

VECU

FMI 13

Out of calibration

No vehicle speed

MIL illuminated

Vehicle speed sensor (VSS)

available to VECU

(13L engine only)

VECU

FMI 19

Received network

Vehicle speed

MIL illuminated

Vehicle speed sensor (VSS)

data in error

deemed

(13L engine only)

VECU

inaccurate by

VECU

ECM SPN 91, Accelerator Pedal Position 1 – MID 128 PID 91

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 9

Abnormal update

Missing signal

N/A

SAE J1587 data link pedal information

rate

from VECU

not available

FMI 13

Out of calibration

Pedal not

MIL illuminated

Accelerator pedal sensor fault

connected to

(13L engine only)

VECU

FMI 10

Abnormal rate of

Pedal position

MIL illuminated

Accelerator pedal sensor fault

change

deemed

(13L engine only)

inaccurate by

VECU

FMI 19

Received network

Pedal position

MIL illuminated

Accelerator pedal sensor fault

data in error

deemed

(13L engine only)

inaccurate by

VECU

ECM SPN 94, Engine Fuel Delivery Pressure – MID 128 PID 94

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 3

Voltage above

Low fuel pressure

N/A

Damaged contacts in harness

normal, or shorted

sensor signal line

Faulty fuel pressure sensor

to high source

voltage

Open circuit.

FMI 5

Current below

Low fuel pressure

N/A

Damaged contacts in harness

normal or open

sensor signal line

Faulty fuel pressure sensor

circuit

voltage

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Codes (DTCs)

FMI 7

Mechanical system

Drop in fuel

Engine derate

Clogged fuel filter

not responding

pressure

Faulty fuel pressure sensor

properly

Leaking fuel line or fitting

Poor fuel pump response

FMI 13

Out of Calibration

Sensor indicates a

N/A

Wiring harness

invalid value

Faulty fuel pressure sensor

Clogged fuel filter

FMI 15

Data valid but above

Sensor indicates a

N/A

Wiring harness

normal operating

invalid value

Faulty fuel pressure sensor

range - Least severe

level

FMI 17

Data valid but below

Sensor indicates a

N/A

Wiring harness

normal operating

invalid value

Faulty fuel pressure sensor

range - Least severe

Clogged fuel filter

level

FMI 18

Data valid but below

Drop in fuel

Engine derate

Clogged fuel filter

normal operating

pressure

Faulty fuel pressure sensor

range - Moderately

Leaking fuel line or fitting

severe level

Poor fuel pump response

ECM SPN 97, Water in Fuel Indicator – MID 128 PID 97

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 0

Data valid but above

Water in fuel is

Uneven running

Water in fuel

normal operational

indicated

Engine stalling

range - Most severe

level

FMI 3

Voltage above

N/A

Undetected water

Open circuit

normal, or shorted

in fuel supply

to high source

Uneven running

Engine stalling

FMI 4

Voltage below

N/A

Undetected water

Short to ground

normal, or shorted

in fuel supply

Open circuit

to low source

Uneven running

Faulty sensor

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Codes (DTCs)

ECM SPN 98, Engine Oil Level – MID 128 PID 98

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 1

Data valid but above

Critically below

Red engine

Low oil level leakage

normal operational

range

shutdown or

Critically low oil level

range

yellow electronic

malfunction

lamps illuminated

dependent of

severity

FMI 4

Voltage below

Short Circuit -

Oil level can not

Engine Oil Level (EOL) sensor failure

normal, or shorted

Positive side

be measured

Faulty harness

to low source

FMI 5

Current below

Short Circuit +,

Oil level can not

Engine Oil Level (EOL) sensor failure

normal or open

Positive side

be measured

Faulty harness

circuit

Open Circuit +,

Positive side

Open Circuit-

Negative side

FMI 18

Data valid but below

Moderately below

Red engine

Low oil level leakage

normal operating

range

shutdown or

Moderately low oil level

range - Moderately

Critically below

Yellow electronic

severe level

range

malfunction

lamps illuminated

dependent of

severity

16

MACK DTCs Service Manual (15)

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

ECM SPN 100, Engine Oil Pressure – MID 128 PID 100

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 1

Data valid but below

Critically below

Engine derate

Oil leakage

normal operational

range

Low pressure

Broken oil pump

range

Red engine

Clogged oil system

shutdown lamp

illuminated

FMI 3

Voltage below

Short Circuit +,

Oil pressure

Engine Oil Pressure (EOP) sensor

normal or shorted

Measuring line

shows 0 in the

failure

low

Open Circuit,

cluster, engine is

Faulty harness

Ground line

running

Yellow electronic

malfunction lamp

illuminated

FMI 5

Current below

Open Circuit +, 5V

Oil pressure

Engine Oil Pressure (EOP) sensor

normal or open

Supply line

shows 0 in the

failure

circuit

Short Circuit -,

cluster, engine is

Faulty harness

Measuring line

running

Yellow electronic

Open Circuit,

Measuring line

malfunction lamps

illuminated

FMI 13

Out of Calibration

Sensor indicates a

Oil pressure

Engine Oil Pressure (EOP) sensor

invalid value

shows 0 in the

failure

cluster, engine is

Faulty harness

running

FMI 15

Data valid but above

Sensor indicates a

Oil pressure

Engine Oil Pressure (EOP) sensor

normal operating

invalid value

shows 0 in the

failure

range - Least severe

cluster, engine is

Faulty harness

level

running

FMI 17

Data valid but below

Sensor indicates a

Oil pressure

Engine Oil Pressure (EOP) sensor

normal operating

invalid value

shows 0 in the

failure

range - Least severe

cluster, engine is

Faulty harness

level

running

ECM SPN 102, Engine Intake Manifold 1 Pressure – MID 128 PID 102

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 2

Data erratic,

Intake Manifold

Engine derate

Faulty harness

intermittent or

Pressure Sensor

MIL lamp

Intake Manifold Pressure sensor

incorrect

output is too high

illuminated

or too low

17

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

FMI 3

Voltage above

A short to battery

Engine derate

Faulty harness

normal, or shorted

in the metering

MIL lamp

Harness connectors

to high source

circuit

illuminated

Intake Manifold Pressure sensor

An open in the

ground circuit

of the Intake

Manifold Pressure

Sensor

FMI 5

Current below

A short to ground

Engine derate

Faulty harness

normal or open

in the harness

MIL lamp

Harness connectors

circuit

An open in the 5

illuminated

Intake Manifold Pressure sensor

volt supply circuit

An open in the

metering circuit

FMI 12

Bad intelligent

Intake Manifold

Engine derate

Faulty harness

device or

Pressure sensor

MIL lamp

Intake Manifold Pressure sensor

component

output is too high

illuminated

Sensor indicates

a invalid value

FMI 13

Out of Calibration

Sensor indicates

Engine derate

Faulty harness

a invalid value

MIL lamp

Harness connectors

illuminated

Intake Manifold Pressure sensor

FMI 14

Special instructions

Intake Manifold

Engine derate

Faulty harness

Pressure sensor

MIL lamp

Intake Manifold Pressure sensor

output is too low

illuminated

Inlet air leakage

Sensor indicates

a invalid value

FMI 15

Data valid but above

Intake Manifold

Engine derate

Faulty harness

normal operating

Pressure sensor

MIL lamp

Harness connectors

range - Leastsevere

output is too high

illuminated

Intake Manifold Pressure sensor

level

FMI 17

Data valid but below

Sensor indicates

Engine derate

Faulty harness

normal operating

a invalid value

MIL lamp

Harness connectors

range - Leastsevere

illuminated

Intake Manifold Pressure sensor

level

ECM SPN 103, Engine Turbocharger 1 Speed – MID 128 PID 103

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 0

Data valid but above

Turbocharger

Engine derate

Miss detection

normal operational

speed is at least

MIL illuminated

Faulty harness

range

25% greater than

Faulty harness connector

the target wheel

speed for the

Turbocharger Speed Sensor

measured boost

18

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

FMI 1

Data valid but below

Turbocharger

Engine derate

Miss detection

normal operational

speed is at least

MIL illuminated

Faulty harness

range - Most severe

25% less than

Faulty harness connector

level

the target wheel

speed for the

Turbocharger Speed Sensor

measured boost

FMI 9

Abnormal update

A fault is logged if

Engine derate

Faulty harness

rate

the Turbocharger

MIL illuminated

Faulty harness connector

Speed Sensor

Turbocharger Speed Sensor

signal is lost

FMI 15

Data valid but above

Turbocharger

Engine derate

Miss detection

normal operating

speed is at least

MIL illuminated

Faulty harness

range - Least severe

25% greater than

Faulty harness connector

level

the target wheel

speed for the

Turbocharger Speed Sensor

measured boost

FMI 17

Data valid but below

Turbocharger

Engine derate

Miss detection

normal operating

speed is at least

MIL illuminated

Faulty harness

range - Least severe

25% less than

Faulty harness connector

level

the target wheel

speed for the

Turbocharger Speed Sensor

measured boost

ECM SPN 105, Engine Intake Manifold 1 Temperature – MID 128 PID 105

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 0

Data valid but above

Sensor indicates a

Engine derate

Poor cooling

normal operational

invalid value

Extreme running conditions

range - Most severe

level

FMI 2

Data erratic,

The Intake

Engine derate

Poor cooling

intermittent or

Manifold

MIL illuminated

Extreme running conditions

incorrect

Temperature

Engine Intake Manifold sensor

sensor output is

too high or too low

Faulty harness

Faulty harness connector

Ambient Air Temperature sensor

FMI 4

Voltage below

N/A

Difficult to start in

Engine Intake Manifold sensor

normal, or shorted

cold climates

Faulty harness

to low source

Minor cold engine

Faulty harness connector

smoke

Engine derate

MIL illuminated

FMI 5

Current below

Possible short to

Difficult to start in

Engine Intake Manifold sensor

normal or open

sensor

cold climates

Faulty harness

circuitt

Engine derate

Faulty harness connector

MIL illuminated

19

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

FMI 13

Out of Calibration

The sensor output

Engine derate

Engine Intake Manifold sensor

is showing a

Minor cold engine

Faulty harness

constant value

smoke

Faulty harness connector

MIL illuminated

FMI 17

Data valid but below

The sensor output

Engine derate

Engine Intake Manifold sensor

normal operating

is showing a

Minor cold engine

Faulty harness

range - Least severe

constant value

smoke

Faulty harness connector

level

MIL illuminated

ECM SPN 108, Barometric Pressure – MID 128 PID 108

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 2

Data erratic,

Barometric

Minor engine

Faulty Sensor

intermittent or

Pressure sensor

derate

Faulty Engine Control Module

incorrect

output is too high

MIL illuminated

or too low

FMI 3

Voltage above

Short to battery on

MIL illuminated

Internal fault in the Engine Control

normal, or shorted

the metering side

Module

to high source

Faulty Sensor

FMI 4

Voltage below

A short to ground

MIL illuminated

Internal fault in the Engine Control

normal, or shorted

on the metering

Module

to low source

side

Faulty Sensor

ECM SPN 110, Engine Coolant Temperature – MID 128 PID 110

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 0

Data valid but above

Coolant

Engine derate

Extreme driving condition

normal operational

temperature

Red engine

Faulty coolant thermostat

range - Most severe

indicates critical

shutdown lamp

Malfunctioning fan

level

limit

illuminated

Blocked radiator

FMI 2

Data erratic,

Engine Coolant

May affect

Faulty Sensor

intermittent or

Temperature

driveability in

Faulty harness

incorrect

sensor output is

extreme cases

Faulty coolant thermostat

too high or too low

MIL illuminated

FMI 4

Voltage below

Engine Coolant

Difficult to start in

Faulty Sensor

normal or shorted

Temperature

cold climates

Faulty harness

low

sensor voltage

Idle run regulation

too low

is deteriorated

MIL illuminated

FMI 5

Current below

N/A

Difficult to start in

Faulty Sensor

normal or open

cold climates

Faulty harness

circuit

Idle run regulation

is deteriorated

MIL illuminated

20

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

FMI 10

Abnormal rate of

Engine Coolant

May affect vehicle

Faulty Sensor

change

Temperature

driveability

Faulty harness

sensor output

MIL illuminated

is showing a

constant value

FMI 13

Out of Calibration

Sensor out of

MIL illuminated

Faulty Sensor

range

Sensor indicates a

invalid value

FMI 16

Data valid but above

Coolant

Engine derate

Extreme driving condition

normal operating

temperature

Yellow electronic

Faulty coolant thermostat

range - Moderately

indicates

malfunction lamp

Malfunctioning fan

severe level

moderate upper

limit

illuminated

Blocked radiator

FMI 17

Data valid but below

Sensor out of

MIL illuminated

Faulty Sensor

normal operating

range

range - Least severe

Sensor indicates a

level

invalid value

ECM SPN 111, Engine Coolant Level – MID 128 PID 111

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 1

Data valid but below

Critically below

Engine derate

Coolant level below range

normal operational

range

Red engine

Faulty harness

range - Most severe

Coolant level can

shutdown lamp

level

not be detected

illuminated

Coolant level can

not be detected

FMI 3

Voltage above

Short Circuit +,

Coolant level can

Faulty harness

normal, or shorted

measuring line

not be detected

Faulty harness connector

to high source

Coolant level can

Yellow electronic

Faulty level sensor

not be detected

malfunction lamp

illuminated

FMI 4

Voltage below

Short Circuit -,

Coolant level can

Faulty harness

normal, or shorted

measuring line

not be detected

Faulty harness connector

to low source

Coolant level can

Yellow electronic

Faulty level sensor

not be detected

malfunction lamp

illuminated

FMI 5

Current below

Open Circuit

Coolant level can

Faulty harness

normal or open

Coolant level can

not be detected

Faulty harness connector

circuit

not be detected

Yellow electronic

Faulty level sensor

malfunction lamp

illuminated

21

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

FMI 14

Special instructions

Sensor out of

Coolant level can

Faulty harness

range

not be detected

Faulty harness connector

Sensor indicates a

Yellow electronic

Faulty level sensor

invalid value

malfunction lamp

illuminated

FMI 18

Data valid but below

Sensor out of

Coolant level can

Faulty harness

normal operating

range

not be detected

Faulty harness connector

range - Moderately

Sensor indicates a

Yellow electronic

Faulty level sensor

severe level

invalid value

malfunction lamp

illuminated

ECM SPN 153, Engine High Resolution Crankcase Pressure – MID 128 PID 153/PSID 23

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 0

Data valid but above

Out of range, max

Red engine

Piston ring blow-by

normal operational

voltage, illegal

shutdown lamp

range - Most severe

Critically Above

illuminated

level

Range

Forced idle

Engine shut down

FMI 2

Data erratic,

Crankcase

MIL illuminated

Faulty Crank Case Pressure senor

intermittent or

pressure

Faulty harness

incorrect

indication to high

or to low a value

FMI 3

Voltage above

Short Circuit +,

MIL illuminated

Faulty Crank Case Pressure senor

normal or shorted to

Measuring line

Yellow electronic

Faulty harness

high source

Open Circuit,

malfunction lamp

Ground line

illuminated

FMI 5

Current below

Open Circuit +, 5V

MIL illuminated

Faulty Crank Case Pressure senor

normal or open

Supply Line

Yellow electronic

Faulty harness

circuit

Short Circuit -,

malfunction lamp

measuring line

illuminated

Open Circuit,

measuring line

FMI 7

Mechanical system

Leakage detected

MIL illuminated

Faulty separator, hoses or pipes

not responding or

in the crankcase

out of adjustment

ventilation system

FMI 13

Out of Calibration

Sensor out of

MIL illuminated

Faulty Sensor

range

Sensor indicates a

invalid value

22

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

FMI 15

Data valid but above

Sensor out of

MIL illuminated

Faulty Sensor

normal operating

range

range - Least severe

Sensor indicates a

level

invalid value

FMI 17

Data valid but below

Sensor out of

MIL illuminated

Faulty Sensor

normal operating

range

range - Least severe

Sensor indicates a

level

invalid value

ECM SPN 158, Keyswitch Battery Potential – MID 128 PID 158/PSID 124

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 0

Data valid but above

Engine Control

N/A

Charging system fault

normal operational

Module battery

External charger

range

voltage too high

Engine control module (ECM)

FMI 1

Data valid but below

Engine Control

Starter will not

Charging system fault

normal operational

Module battery

crank

Battery

range

voltage too low

Ground connection

FMI 3

Voltage above

Engine Control

N/A

Charging system fault

normal, or shorted

Module battery

External charger

to high source

voltage too high

Engine control module (ECM)

FMI 4

Voltage below

Engine Control

Starter will not

Charging system fault

normal, or shorted

Module battery

crank

Battery

to low source

voltage too low

Ground connection

FMI 16

Data valid but above

Engine Control

N/A

Charging system fault

normal operating

Module battery

External charger

range - Moderately

voltage too high

Engine control module (ECM)

severe level

FMI 18

Data valid but below

Engine Control

Starter will not

Charging system fault

normal operating

Module battery

crank

Battery

range - Moderately

voltage too low

Ground connection

severe level

ECM SPN 171, Ambient Air Temperature – MID 128 PID 171

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 2

Data erratic,

Key ON, Ambient

N/A

Faulty instrument cluster

intermittent or

Air Temperature

Faulty harness

incorrect

message missing

onSAEJ1939and

SAE J1587 data

links

23

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

FMI 9

Abnormal Update

Key ON, Ambient

N/A

Faulty instrument cluster

Rate

Air Temperature

Faulty harness

message missing

on SAE J1587

data link

FMI 10

Abnormal rate of

Ambient

MIL illuminated

Faulty instrument cluster

change

Temperature

(13L engine only)

sensor signal fault

FMI 12

Bad intelligent

Loss of SAE

MIL illuminated

Faulty instrument cluster

device or

J1939 data link

(13L engine only)

Faulty harness

component

communication

between Engine

Control Module

and Instrument

Cluster Control

Module

FMI 13

Out of calibration

Ambient

MIL illuminated

Faulty instrument cluster/harness or

Temperature

(13L engine only)

cluster harness connectors

sensor signal fault

No ambient

temperature

calculated by

Vehicle ECU

No valid ambient

temperature

received by

Engine Control

Module

FMI 14

Special instructions

Ambient

MIL illuminated

Ambient Temperature sensor signal

Temperature

missing from Vehicle ECU

sensor signal fault

FMI 19

Received network

Ambient

MIL illuminated

Faulty instrument cluster

data in error

Temperature

(13L engine only)

sensor signal fault

ECM SPN 173, Engine Exhaust Gas Temperature (EGT) – MID 128 PID 173

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 0

Data valid but above

Exhaust Gas

Engine derate

Faulty harness

normal operational

Temperature is

Poor driveability

Faulty harness connector

range - Most severe

critically high

Regeneration is

Intake air leak

level

not possible

FMI 2

Data erratic,

Sensor is not

MIL illuminated

Faulty harness

intermittent or

rational

Regeneration is

Faulty harness connector

incorrect

not possible

Exhaust leak

Intake air leak

Sensor failure

24

Group 28

Engine Control Module (ECM) Diagnostic Trouble

Codes (DTCs)

FMI 4

Voltage below

Short to ground on

MIL illuminated

Sensor failure

normal, or shorted

the metering side

Regeneration is

Faulty harness

to low source

of the circuit

not possible

Faulty harness connector

Aftertreatment control module (ACM)

FMI 5

Current below

Short to battery on

MIL illuminated

Faulty harness

normal or open

the metering side

Sensor failure

circuit

of the circuit

Faulty harness connector

Open in the

metering side of

the circuit

Open in the

ground side of

the circuit

FMI 15

Data valid but above

Sensor out of

MIL illuminated

Sensor failure

normal operating

range

Faulty harness

range - Least severe

Sensor indicates a

level

invalid value

FMI 16

Data valid but above

Exhaust Gas

Engine derate

Faulty harness

normal operating

Temperature is

Poor driveability

Faulty harness connector

range - Moderately

moderately too

Intake air leak

severe level

high

ECM SPN 175, Engine Oil Temperature 1 – MID 128 PID 175

Type of

FMI Description:

Fault Condition:

Possible

Possible Cause:

fault:

Symptoms:

FMI 0

Data valid but above

Extreme driving

Red engine

Extreme driving conditions

normal operational

conditions

shutdown lamp

Engine cooling fan

range - Most severe

Engine oil

illuminated

Oil thermostat

level

temperature

Engine derate

Coolant system

critically above

range

Clogged oil cooler

FMI 2

Data erratic,

Engine oil

MIL illuminated

Engine Oil Temperature (EOT) sensor

intermittent or

temperature

(13L engine only)

failure

incorrect

sensor indicating

In some cases

Faulty harness

too high or too low

may have

a value (abnormal

an effect on

value)

driveability

FMI 4

Voltage below

Short circuit -,

MIL illuminated

Engine Oil Temperature (EOT) sensor

normal, or shorted

measuring line

(13L engine only)

failure

to low source

Yellow electronic

Faulty harness

malfunction lamp

illuminated

25

MACK DTCs Service Manual (16) Loading...

MACK DTCs Service Manual (2024)

FAQs

What is the code P026C on a Mack truck? ›

OBD2 Diagnostic Trouble Code P026C means that Fuel Injection Quantity 'A' Lower Than Expected has been detected.

Which of the following electronic control units are used in the Mack vehicle management and control IV? ›

Six electronic control units (ECUs) are used; the engine control module (ECM), instrument control module (ICM), Vehicle Electronic Control Unit (VECU), transmission control module (TCM), the gear selector control module (GSCM) and the aftertreatment control module (ACM).

What is the code 6 4 on a Mack blink? ›

A 6-4 Code indicate loss of communications between the VECU(Vechile Electronic Control Unit) and the EECU (Engine Electronic Control Unit). If you disconnect the ABS ECU and measure the resistance across the yellow and green wires (J1939 High and Low) you should have 60 Ohms.

What causes a P026C code? ›

This code sets when the engine computer has detected that the fuel injection quantity is lower than expected, so essentially the computer is seeing that there is not fuel being included as part of the mixture.

What is the code p20ee00 on a Mack truck? ›

The P20EE code indicates an issue with the vehicle's catalyst efficiency. It's a generic diagnostic trouble code that generally has to do with how your vehicle is converting NOx to nitrogen and water using the diesel exhaust fluid (DEF).

Where is the transmission control module on a Mack? ›

The Transmission Control Module located on the upper portion of the control housing. The Clutch Position Sensor is located on the side of the clutch cylinder assembly (inside bell housing). The speed sensors are located on the control housing and measure the speed of the main shaft and the speed of the countershaft.

What does the ECU unit control? ›

Engine control unit (ECU) is an electronic control unit that ensures the optimal work of an internal combustion engine. It controls fuel supply and injection, fuel-to-air ratio, ignition, idle speed, and the timing of valve opening and closing.

What is ECU control system? ›

An electronic control unit (ECU) is a small device inside a vehicle that controls one or several electrical systems in that vehicle. It tells electrical systems what to do and how to operate. ECU's core is a microcontroller and it is controlled by embedded software.

What is Mack fault code 131? ›

CODE REASON EFFECT

Fault Code: 131 Accelerator Pedal or Lever Position Automotive: Severe derate. PID: P091 Sensor Circuit - Shorted High. High in power output of the. SPN: 91 voltage detected at accelerator pedal or engine.

What is ACC sensor on Mack truck? ›

Adapts the vehicle's speed to the flow of traffic

ACC helps drivers by adapting the vehicle's speed to the flow of traffic and maintaining an adequate, safe distance to the vehicle in front.

What is the code 6 1 on a Mack engine? ›

The Electronic Malfunction Lamp (EML) will turn on and fault code 6-1 will set when the Fuel Level (FL) Sensor signal voltage is less than 0.25 volts or greater than 4.5 volts for 2 seconds. If the signal voltage returns to between 0.25 volts and 4.5 volts for 2 seconds, the fault will become inactive.

How do you clear a truck code? ›

Leaving the battery disconnected for a few minutes will ensure the vehicle systems will completely reset when you reconnect the battery. Secure the negative cable back to the terminal and cover it with the cap. Disconnecting the battery will clear the error codes and reset the check engine light.

What is a fault code in a truck? ›

Fault codes, also known as diagnostic trouble codes (DTCs), are specific codes that your vehicle's computer generates when it detects an issue or malfunction within your car. These codes help mechanics and vehicle owners identify what the exact problem is and how to fix it.

What is the code po4db? ›

A P04DB Code obtained from the Engine Control Unit (ECU) indicates a disconnected, damaged, or malfunctioning crankcase ventilation system. This diagnostic monitors the Positive Crankcase Ventilation (PCV) system for leaks and malfunctions.

References

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