Circuit DescriptionThe sensor supply 1 circuit of the engine control module (ECM) provides a 5 volt supply to various sensors on the engine harness. Refer to the wiring diagram for sensor supply identification.

Component LocationSensor Supply 1 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 1 signal voltage was less than 4.75-VDC for more than one 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.A default value is used for all of the sensors on the sensor supply 1 circuit.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 wire can be caused by a short circuit to ground in a supply wire, a short circuit between a supply wire and a return wire, a malfunctioning sensor, or a malfunctioning ECM power supply.

During the fault code response test outlined for each sensor connected to sensor supply number 1, Fault Code 352 must be active before unplugging each sensor. If the fault code is not active, but can be easily duplicated by operating the engine, the following can be performed:

• Operate the engine under the conditions that will cause Fault Code 352 to become active, even if it logs for a short period of time. Unplug one sensor at a time until Fault Code 352 stops logging under the test conditions. Each sensor can be unplugged with the engine running. Note: The engine may not start if the camshaft position sensor is unplugged.

Possible Cause:1) Camshaft position sensor failure2) Intake manifold pressure/temperature sensor failure3) Crankcase pressure sensor failure4) Engine oil pressure sensor failure5) Barometric air pressure sensor failure6) Engine harness7) ECM calibration