Circuit DescriptionThe sensor supply 3 circuit provides a 5 volt supply to the primary engine speed/position sensor.

Component LocationSensor Supply 3 originates in the engine wiring harness. It provides 5 VDC to the engine crankshaft speed/position sensor.

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 3 signal voltage was greater than 5.25-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.The backup engine speed sensor will be used by the ECM for the engine speed signal.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.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.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 TalkHigh voltage on the +5 volt supply wire can be caused by a short to battery voltage in the engine harness or connectors, or a damaged ECM.

Possible Cause:1) Engine harness2) ECM calibration