P0563

Engine Controls Schematics: Power and Ground:

CIRCUIT DESCRIPTION
The PCM continuously monitors the system voltage. The system voltage information is taken from the PCM ignition feed circuits. Since voltages below 8.0 volts or above 18.0 volts, could cause improper system operation and/or component damage, the PCM operates in a default mode if a PCM voltage DTC sets. If the system voltage is high, the PCM disables most outputs to protect the hardware. A scan tool may not display data if system voltage is outside this range. Use a DMM to monitor system voltage to verity if the fault is currently present. A high voltage may cause a stalling condition, or other driveability concerns.

CONDITIONS FOR RUNNING THE DTC
The engine run time is more than 10 seconds.

CONDITIONS FOR SETTING THE DTC
^ The PCM senses the system voltage is above 18.0 volts.
^ All the conditions are present for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM stores DTC P0563 in the PCM memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The PCM will record the operating conditions at the time the diagnostic fails. The PCM stores this information in Failure Records.
^ The PCM disables most outputs.
^ The transmission defaults to third gear.
^ The TCC operation is inhibited.
^ The PCM will cycle the cooling fans ON and OFF every few seconds during the time the condition is present.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A History DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
^ Use a scan tool in order to clear the MIL/DTC.

DIAGNOSTIC AIDS

IMPORTANT:
^ Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
^ For any test that requires probing the PCM or a component harness connector, use the J 35616-A connector test adapter kit. Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Diagrams.

Inspect the generator voltage sense circuit for high resistance or loose connections. These could cause an intermittent overcharging condition. Refer to A Diagnostic Starting Point - Engine Electrical in Starting and Charging.

For an intermittent condition, refer to Symptoms. Symptom Related Diagnostic Procedures

TEST DESCRIPTION

Diagnostic Chart:

The numbers below refer to the step numbers on the diagnostic table.
2. This step tests for excessive generator output. The voltage should remain below 18.0 volts.