PACCAR PX-9 CM2350 (2013-17) Fault Code:2635 PID:SID 27 SPN:641 FMI:31 VGT Actuator Driver Circuit – Condition Exists

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