P1635

DTC P1635 5 Volt Reference Low






Circuit Description

The PCM provides a 5 volt supply for use in powering up the sensors. This test monitors the voltage present at terminals BRD13 (shared by BARO and Crankshaft Position sensors) and BRD14 (the Optical/Fuel temperature sensor (Cam/HI. Res)).

Conditions for Running the DTC

The ignition switch in the on position.

Conditions for Setting the DTC

The PCM 5 volt reference is less than 1 volt.

Action Taken When the DTC Sets

^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Failure Records.

Conditions for Clearing the MIL/DTC

^ A History DTC will clear after forty consecutive warm-up cycles, it this or any other emission related diagnostic does not report any failures.
^ Use of a scan tool will clear the DTC codes.

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

Number(s) below refer to the step number(s) on the Diagnostic Table.

2. Checks to confirm that a DTC is still present.
3. Checks to determine if there is a 5 volt reference from the PCM.
4. Checks to determine 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 on the engine or the short is in the wiring harness.