Circuit DescriptionThe VGT is electronically activated by the VGT actuator. The VGT actuator is a smart device that receives information via the J1939 data link from the primary engine control module (ECM). The VGT actuator performs its own diagnostics and reports errors back to the primary engine ECM with the J1939 data link.

Component LocationThe VGT actuator is located on the turbocharger bearing housing.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is initially turned to the ON position.

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 CodesThe ECM has detected an abnormal VGT position at key ON.

Action Taken When the Fault Code is ActiveThe ECM logs the fault code 10 seconds after the diagnostic runs and fails.Conditions for Clearing the Fault CodeThe keyswitch must be completely turned OFF for more than 30 seconds before this diagnostic will run at initial key ON.

The fault code will become inactive if the error condition no longer exists.

Shop TalkVerify the ECM calibration is correct. Check the calibration revision history found on QuickServe? Online for applicable corrections to the calibration stored in the ECM. If necessary, calibrate the ECM.

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.

Inspect the turbocharger vanes for residue, and clean the vanes, if required. Find the source of the residue and repair.

Possible Cause:1) Turbocharger assembly failure2) ECM calibration