CM850 Electronic Control System – FAULT CODE 958

VGT Position Sensor – Data Erratic, Intermittent, or Incorrect


Fault Code: 958
PID: P27
SPN: 2795
FMI: 2
LAMP: Amber

VGT Position Sensor – Data erratic, intermittent, or incorrect. Intermittent variable geometry turbocharger (VGT) position information is being received by the electronic control module (ECM).

Possible low power. Power to the turbocharger actuator will be limited.

Variable Geometry Turbocharger (VGT) Position Sensor Circuit

Circuit Description

The turbocharger position sensor outputs a voltage signal to the ECM. The ECM converts this signal into a percentage value, 0 to 100 percent, indicating turbocharger position. A fully closed turbocharger actuator is equivalent to 100 percent.

Component Location

The turbocharger position sensor is located on the variable geometry turbocharger (VGT) actuator assembly. Refer to Procedure 100-002 for a detailed component location view.

Shop Talk

This fault code is caused by an internal failure of the variable geometry turbocharger (VGT) position sensor. This failure causes erratic readings of the variable geometry turbocharger (VGT) position. The troubleshooting information for fault code 958 is the same as fault code 1229. Refer to fault code 1229 for the fault code troubleshooting information.

Refer to Troubleshooting Fault Code t05-958

Last Modified:  08-Jul-2010