SPN 641 - FMI 12 (Fault Code 2634)

SPN 641 FMI 12
SPN641 FMI12
VGT Actuator Controller - Bad Intelligent Device or Component

ISB, ISC, and ISL - VGT Actuator Circuit

Fault Code: 2634
PID(P), SID(S): S027
SPN: 641
FMI: 12/12
Lamp: Red

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

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 that receives information via the J1939 data link from the primary engine  electronic control module (ECM). The VGT actuator performs its own diagnostics and reports errors back to the primary engine ECM using the J1939 data link.

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 VGT actuator has detected an internal error in the VGT smart device.

Action Taken When the Fault Code is Active:
• The ECM illuminates the red STOP ENGINE light immediately when the diagnostic runs and fails.
• VGT actuation will be disabled.

Conditions for Clearing the Fault Code:
The diagnostic will clear at initial key-on if the error condition no longer exists. The ECM will turn off the amber CHECK ENGINE light and enable VGT operation immediately after the diagnostic runs and passes.

Shop Talk:
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.

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.

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. Perform the aftertreatment initial check procedure to test for a damaged diesel particulate filter.

Read More:


Subscribe to receive free email updates:

0 Response to "SPN 641 - FMI 12 (Fault Code 2634)"

Post a Comment