Circuit DescriptionThe engine control module (ECM) provides a 5 volt supply to the intake manifold pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The intake manifold pressure sensor provides a signal to the ECM on the intake manifold pressure sensor signal circuit. This sensor signal voltage changes, based on the pressure in the intake manifold.

The ECM uses the intake manifold pressure reading to monitor turbocharger performance.

Component LocationThe intake manifold pressure sensor is located in the intake manifold.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is operating.

Conditions for Setting the Fault CodesThe ECM detects that the variable geometry turbocharger (VGT) actuator is slow to meet commanded position.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.Conditions for Clearing the Fault CodeTo validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop-and-go city driving and steady state highway driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.To validate the repair using a Chassis Dynamometer Test, utilize a routine that incorporates acceleration and motoring events, steady state highway operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.For On-Board Diagnostics (OBD) engines, the ECM will turn off the malfunction indicator lamp (MIL) after three consecutive trips where the diagnostic runs and passes.The “Reset All Faults” command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD engines.

Shop TalkPossible causes of this fault are:

A malfunctioning VGTHigh exhaust restriction.

Possible Cause:1) VGT actuator failure2) Turbocharger failure3) ECM calibration