Paccar

Reason:
Auxiliary PWM Driver 1 Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the pulse width modulation (PWM) auxiliary circuit.

Effect:
Possible reduced engine performance.

Circuit Description:
The transmission shift modulator uses this signal from the electronic control module (ECM) to determine when to shift the transmission. The return circuit is dependent on original equipment manufacturer (OEM) wiring. It may be wired back to the ECM on some vehicles or wired to chassis or block ground on others. Consult the OEM wiring diagram for return circuit details.

Component Location:
Refer to the OEM wiring diagram for the location of the transmission shift modulator.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected low signal voltage at the analog torque circuit.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) A malfunctioning transmission shift modulator
2) An short circuit to ground on the output device driver line
3) A short pin-to-pin in the output device driver line

Reason:
Engine Charge Air Cooler Outlet Temperature – Voltage above normal, or shorted to high source

Effect:
None on performance

Circuit Description:
The electronic control module (ECM) uses the charge air cooler temperature sensor to measure the charge air cooler outlet temperature. The charge air cooler temperature sensor contains a variable resistor sensor and is used to measure the temperature of the air exiting the charge air cooler. The ECM supplies 5 volts to the charge air cooler temperature sensor signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the temperature of the air entering the charge air cooler.

Component Location:
The charge air cooler temperature sensor is located on the charge air cooler housing .

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the compressor intake temperature signal voltage was out of range high.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and let it idle for 1 minute.
2) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) Open circuit in the harness
2) Open return circuit in the harness, connectors, or sensor

Reason:
Engine Charge Air Cooler Outlet Temperature – Voltage Below Normal or Shorted to Low Source.

Effect:
None on performance

Circuit Description:
The electronic control module (ECM) uses the charge air cooler temperature sensor to measure the charge air cooler outlet temperature. The charge air cooler temperature sensor contains a variable resistor sensor and is used to measure the temperature of the air exiting the charge air cooler. The ECM supplies 5 volts to the charge air cooler temperature sensor signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the temperature of the air entering the charge air cooler.

Component Location:
The charge air cooler temperature sensor is located on the charge air cooler housing .

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the engine charge air cooler outlet temperature signal voltage was out of range low.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and let it idle for 1 minute.
2) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) Short circuit to ground in the engine harness, sensor, or ECM

Reason:
VGT Actuator Controller – Bad Intelligent Device or Component. An internal error has been detected by the smart VGT controller.

Effort:
Possible reduced engine performance.

Circuit Description:
The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device and receives information via the J1939 data link from the primary engine control module (ECM). The VGT actuator performs its own diagnostics and reports malfunctions back to the primary engine ECM, using the J1939 data link. The ECM then decodes the error message and converts it to a fault code.

Component Location:
The VGT actuator is located on the turbocharger bearing housing.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Variable Geometry Turbocharger (VGT) detected an internal error in the VGT smart device.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the red STOP ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) VGT actuation will be disabled.
3) Active and stationary regeneration of the diesel particulate filter will be disabled.
4) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
5) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
This fault code is logged when the VGT smart actuator detected an internal error within the VGT actuator. The VGT actuator will stop controlling the turbocharger when this fault code is active. Fault Code 2634 will become active if the VGT actuator is removed from the turbocharger and then the keyswitch is turned to the ON position; or it may be possible for it to become active if the actuator fails the install/calibrate procedure. If this occurs, disconnect the VGT actuator from the engine harness with the keyswitch ON, and connect the VGT actuator to the engine harness. Fault Code 2634 should go inactive. Follow the VGT actuator installation procedure to install the VGT actuator.

Possible Causes:
1) Inactive fault codes
2) Damage to the aftertreatment system
3) Faulty ECM

Reason:
VGT Actuator Driver Circuit – Condition Exists. A calibration mismatch between the VGT actuator and the ECM has been detected.

Effect:
VGT actuation will be disabled

Circuit Description:
The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device and receives information via the J1939 data link from the primary engine control module (ECM). The VGT actuator performs its own diagnostics and reports malfunctions back to the primary engine ECM, using the J1939 data link. The ECM then decodes the error message and converts it to a fault code.

Component Location:
The VGT actuator is located on the turbocharger bearing housing.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
This fault code can be activated for the following reasons:
1) The Engine Control Module (ECM) detected a calibration incompatibility between the VGT actuator and the ECM calibration
2) The Variable Geometry Turbocharger (VGT) detected the system voltage was incorrect for the VGT actuator part number.
3) The Engine Control Module (ECM) detected an incorrect VGT actuator installed on the turbocharger.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the red STOP ENGINE lamp immediately after the diagnostic runs and fails.
2) VGT actuation will be disabled.
3) Active and stationary regeneration of the diesel particulate filter will be disabled.
4) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
5) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
This fault code is logged when the ECM has detected that an incorrect VGT actuator has been installed on the turbocharger.

Possible Causes:
1) Faulty ECM
2) Inactive fault codes

Reason:
VGT Actuator Driver Circuit – Condition Exists. A calibration mismatch between the VGT actuator and the ECM has been detected.

Effect:
VGT actuation will be disabled

Circuit Description:
The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device and receives information via the J1939 data link from the primary engine control module (ECM). The VGT actuator performs its own diagnostics and reports malfunctions back to the primary engine ECM, using the J1939 data link. The ECM then decodes the error message and converts it to a fault code.

Component Location:
The VGT actuator is located on the turbocharger bearing housing.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
This fault code can be activated for the following reasons:
1) The Engine Control Module (ECM) detected a calibration incompatibility between the VGT actuator and the ECM calibration
2) The Variable Geometry Turbocharger (VGT) detected the system voltage was incorrect for the VGT actuator part number.
3) The Engine Control Module (ECM) detected an incorrect VGT actuator installed on the turbocharger.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the red STOP ENGINE lamp immediately after the diagnostic runs and fails.
2) VGT actuation will be disabled.
3) Active and stationary regeneration of the diesel particulate filter will be disabled.
4) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
5) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
This fault code is logged when the ECM has detected that an incorrect VGT actuator has been installed on the turbocharger.

Possible Causes:
1) Faulty ECM
2) Inactive fault codes

Reason:
VGT Actuator Driver Circuit – Abnormal Update Rate. No communications on the J1939 data link between the engine ECM and the smart VGT controller.

Effect:
Possible reduced engine performance

Circuit Description:
The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device and receives information via the J1939 data link from the primary engine control module (ECM). The VGT actuator performs its own diagnostics and reports malfunctions back to the primary engine ECM, using the J1939 data link. The ECM then decodes the error message and converts it to a fault code.

Component Location:
The VGT actuator is located on the turbocharger bearing housing.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) did not receive a valid J1939 data link message from the Variable Geometry Turbocharger (VGT) actuator for more than 1 second.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the red STOP ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) VGT actuation will be disabled.
3) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
4) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
N/A

Possible Causes:
1) The VGT actuator is not receiving power from the ECM. This can be caused by an open circuit in the power supply wire or low voltage supplied by the primary engine ECM.
2) Rapid cycling of the keyswitch
3) An open return circuit on the VGT actuator circuit
4) An open or short circuit on the J1939 data link circuit between the ECM and VGT actuator
5) Intermittent communications between the VGT actuator and the primary engine ECM on the J1939 data link
6) A damaged termination resistor in the engine data link harness

Reason:
Aftertreatment Diesel Oxidation Catalyst Conversion Efficiency – Data Valid But Below Normal Operating Range – Moderately Severe Level. The temperature increase across the aftertreatment catalyst is lower than expected.

Effect:
Possible frequent need for aftertreatment regeneration

Circuit Description:
The aftertreatment diesel particulate filter temperature sensor module is a smart device that communicates with the engine control module via the J1939 data link. The aftertreatment diesel partculate filter temperature sensor module performs its own internal diagnostics and reports malfunctions back to the engine control module using the J1939 data link. The aftertreatment diesel particulate filter temperature sensor module is used to measure the aftertreatment diesel oxidation catalyst intake temperature, aftertreatment diesel particulate filter intake temperature, and aftertreatment diesel particulate filter outlet temperature. The temperature probes are permanently attached to the aftertreatment diesel particulate filter temperature sensor module and can not be replaced individually.

Component Location:
The aftertreatment diesel oxidation catalyst is located in the exhaust system. The location of the catalyst can vary, depending on the original equipment manufacturer (OEM). Refer to the OEM service manual.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running and active regeneration of the aftertreatment diesel particulate filter is occurring.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) calculated the DOC efficiency was less than required to successfully complete a regeneration.

Action Taken When the Fault Code is Active:
The ECM logs the fault code immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and perform the INSITE™ electronic service tool
2) Aftertreatment Diesel Particulate Filter Regeneration Test.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) A malfunctioning diesel oxidation catalyst
2) A malfunctioning aftertreatment fuel injector

Reason:
Aftertreatment Diesel Oxidation Catalyst Conversion Efficiency – Data Valid But Below Normal Operating Range – Moderately Severe Level. The temperature increase across the aftertreatment catalyst is lower than expected.

Effect:
Possible frequent need for aftertreatment regeneration

Circuit Description:
The aftertreatment diesel particulate filter temperature sensor module is a smart device that communicates with the engine control module via the J1939 data link. The aftertreatment diesel partculate filter temperature sensor module performs its own internal diagnostics and reports malfunctions back to the engine control module using the J1939 data link. The aftertreatment diesel particulate filter temperature sensor module is used to measure the aftertreatment diesel oxidation catalyst intake temperature, aftertreatment diesel particulate filter intake temperature, and aftertreatment diesel particulate filter outlet temperature. The temperature probes are permanently attached to the aftertreatment diesel particulate filter temperature sensor module and can not be replaced individually.

Component Location:
The aftertreatment diesel oxidation catalyst is located in the exhaust system. The location of the catalyst can vary, depending on the original equipment manufacturer (OEM). Refer to the OEM service manual.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running and active regeneration of the aftertreatment diesel particulate filter is occurring.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) calculated the DOC efficiency was less than required to successfully complete a regeneration.

Action Taken When the Fault Code is Active:
The ECM logs the fault code immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and perform the INSITE™ electronic service tool
2) Aftertreatment Diesel Particulate Filter Regeneration Test.
3) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) A malfunctioning diesel oxidation catalyst
2) A malfunctioning aftertreatment fuel injector