P1635

DTC P1635 PCM 5 Volt Reference Low






Circuit Description

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

Conditions for Setting the DTC

5 volt reference is less than volt.

Action Taken When the DTC Sets

^ Backup fuel.
^ No EGR.
^ No turbo boost.

Conditions for Clearing the MIL/DTC

^ A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (16O°F) that same ignition cycle).
^ Use of a scan.

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 number(s) on the diagnostic table.

1. Checks to confirm that a DTC is still present.

2. Checks to determine if there is a 5 volt reference from the PCM.

3. Checks to determine if there is a short-to-ground in CKT 350 or CKT 375, or a short-to-ground in the PCM.