P1635

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) provides a 5-volt supply for use in powering up the sensors. This test monitors the voltage present at terminals BRD13, shared by boost and Crankshaft Position (CKP) sensors, and BRD14, the optical/fuel temperature sensor (Cam/HI. Res).

CONDITIONS FOR RUNNING THE DTC
The ignition is in the ON position.

CONDITIONS FOR SETTING THE DTC
The 5-volt reference is less than 1 volt.

ACTION TAKEN WHEN THE DTC SETS
^ The control module stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
^ The driver information center, if equipped, may display a message.

CONDITIONS FOR CLEARING THE DTC
^ A current DTC Last Test Failed clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ Use a scan tool in order to clear the DTC.

DIAGNOSTIC AIDS
During the time the failure is present, the setting of additional DTCs that share a 5-volt reference may also set.

TEST DESCRIPTION

Steps 1-13:

The numbers below refer to the step numbers on the diagnostic table.
2. This step confirms whether a DTC is still present.
3. This step determines if there is a 5-volt reference from the PCM.
4. This step determines if there is a short to ground in the reference circuit or a short-to-ground in the PCM.
7. This step determines if the short is being caused by one of the sensors or the short is in the wiring harness.