PACCAR PX-8 CM2150 (2007-09) Fault Code: 2636 PID: SID 027 SPN: 641 FMI: 9 VGT Actuator Driver Circuit – Abnormal Update Rate. No communications on the J1939 data link between the engine ECM and the smart VGT controller.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe™ Online for applicable fixes to the calibration stored in the ECM. If necessary, calibrate the ECM again.

This fault code is logged when the primary engine ECM does not receive valid J1939 information from the VGT actuator.

Troubleshoot high inactive counts of Fault Code 2636 as an active fault code.

Possible causes:

1)The VGT actuator is not receiving power from the ECM. This could be caused by an open circuit in the power supply wire or low voltage supplied by the primary engine ECM
2)An open return circuit on the VGT actuator circuit
3)An open or short circuit on the J1939 data link circuit between the ECM and VGT actuator
4)Intermittent communications between the VGT actuator and the primary engine ECM on the J1939 data link
5)Rapid cycling of the keyswitch
6)Connector pins are not installed in the appropriate locations specified by the wiring diagram.
7)A damaged termination resistor in the engine data link harness
8)A damaged engine ECM.

The aftertreatment system must be inspected after making the appropriate repair outlined in this fault code troubleshooting tree. Progressive damage to the aftertreatment system may have occurred. Use the following procedures to perform the aftertreatment initial check procedure to test for a damaged diesel particulate filter

Possible repairs:

1)Replace the VGT actuator.
2)Flush the dirt, debris or moisture from the connector pins.
3)Replace the engine harness.
4)Replace the OEM harness.
5)Check the battery voltage and the OEM wiring between the battery and the ECM power harness connector.
6)Replace the J1939 termination resistor.
7)If necessary, calibrate the ECM.