Circuit DescriptionThe exhaust gas pressure sensor is used to measure exhaust gas pressure in the exhaust manifold. This information is used by the electronic control module (ECM) to control emissions and exhaust gas recirculation (EGR) valve operation. The ECM provides a 5 volt supply to the exhaust gas pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The exhaust gas pressure sensor provides a signal to the ECM on the exhaust gas pressure sensor signal circuit. This sensor signal voltage changes, based on the pressure in the exhaust manifold.
Component LocationThe exhaust gas pressure sensor is located above the front section of the exhaust manifold and is plumbed into the exhaust manifold.
Conditions for Running the DiagnosticsThis diagnostic consists of two parts.
One part runs immediately after the keyswitch is turned OFF, and the engine coolant temperature is above 70?C or 158?F.The second part runs continuously when the engine is operating.Conditions for Setting the Fault CodesThe ECM detects that the exhaust pressure reading is higher or lower than the other absolute pressure sensors when the keyswitch is OFF and the engine is not running.The fault code can also be set if the ECM detects that the exhaust pressure is higher or lower than expected during normal engine operation.Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp and/or malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.The ECM will estimate the exhaust gas pressure reading.Diesel exhaust fluid injection into the aftertreatment system is disabled.Active and stationary regeneration of the diesel particulate filter will be disabled.The EGR valve will be closed.Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.Conditions for Clearing the Fault CodeTo validate the repair, make sure the engine coolant temperature is above 70?C or 158?F. Operate the engine if necessary.Cycle the keyswitch to the ON position for 30 seconds, then cycle the keyswitch to the OFF position for 30 seconds. Start the engine and let it high idle for up to 5 minutes.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 Diagnostic (OBD) engines, the ECM will turn off the 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 applications.
Shop TalkPossible causes of this fault code include:
Stuck in-range exhaust gas pressure sensor readingHigh resistance in the exhaust gas pressure sensor signal or return linesPlugging or restriction in the exhaust gas pressure sensor tubeLeaks in the exhaust systemIn-range malfunction of the intake manifold temperature sensor, EGR differential pressure sensor, or intake manifold temperature sensor.
Possible Cause:1) Engine harness2) ECM calibration