P1635

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The PCM uses the 5 volt Reference A circuit to supply voltage to the following sensors:
^ Throttle position (TP) sensor
^ Manifold Absolute Pressure (MAP) sensor
^ Exhaust Gas Recirculation (EGR) pintle position sensor

The PCM monitors the voltage on the 5 volt Reference A circuit. If the voltage is outside an acceptable range, DTC P1635 will set.

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

CONDITIONS FOR SETTING THE DTC
^ The PCM detects a voltage out of range condition on the 5 volt Reference A circuit.
^ The condition exists for less than 1 second.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
^ The PCM stores the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions in Symptoms. Intermittent Conditions