PACCAR PX-9 CM2350 (2013-17) Fault Code:3616 PID:SID 27 SPN:2633 FMI:7 Engine VGT Nozzle Position – Mechanical System Not Responding or Out of Adjustment

Reason:
Engine VGT Nozzle Position – Mechanical System Not Responding or Out of Adjustment. The smart VGT controller has detected incorrect stop limits or the VGT is unable to move to the closed position.

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 at initial key ON and occasionally during engine operation. The keyswitch must be turned OFF for more than 30 seconds before this diagnostic will run at initial key ON.

Conditions for Setting the Fault Codes:
The Variable Geometry Turbocharger (VGT) actuator position could not meet the commanded position for greater than 10 seconds.

Action Taken When the Fault Code is Active:
1) The ECM logs the fault code immediately when the diagnostic runs and fails.
2) The VGT actuator will continue to attempt to meet the commanded position.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, and leave the keyswitch in the ON position for 1 minute. Note that the keyswitch must be completely turned OFF for more than 30 seconds before this diagnostic will run at initial key ON.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
This is an informational fault code indicating that the VGT actuator was unable to go to the desired position at key ON. While active, the ECM will continuously attempt to restore normal VGT operation until the engine coolant temperature reaches 74°C [165°F]. If the condition continues to exist after the coolant reaches 74°C [165°F], Fault Code 2387 will become active and Fault Code 3616 will become inactive. Fault Code 2346 may set due to a resulting fueling derate. Large boost pressure leaks can also cause this fault code.

Possible Causes:
1) Inactive fault codes
2) Faulty turbocharger assembly
3) Faulty ECM