Circuit DescriptionThe sensor supply 6 circuit of the engine control module (ECM) is a dedicated (+) 5-VDC supply for the fuel rail pressure sensor.

Component LocationSensor Supply 6 originates in the Engine Wiring Harness portion of the ECM. It supplies 5 volts to sensors in the engine wiring harness.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault CodesThe Engine Control Module (ECM) detected the sensor supply 6 signal voltage was less than 4.8-VDC for more than 1 second.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.Conditions for Clearing the Fault CodeTo validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.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 immediately after the diagnostic runs and passes.For On-Board Diagnostics (OBD) engines, the ECM will extinguish 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 applications.

Shop TalkLow voltage on the 5 volt supply line can be caused by a short circuit to ground in the supply line, a short circuit between the supply line and a return line, a failed sensor, or a damaged ECM power supply.

Possible Cause:1) Fuel rail pressure sensor failure2) Engine harness3) ECM calibration