P0563

DTC P0563

CIRCUIT DESCRIPTION
The engine control module (ECM) monitors the system voltage on the ignition feed terminal to make sure that the voltage stays within the proper range. If the ECM detects an excessively high system voltage, this DTC will set.

Condition for Setting the DTC
- The ECM detects that the ignition 1 feed circuit voltage is more than 16.5 volts for longer than 5 seconds.

Action Taken When the DTC Sets
12,000 lbs GVW
- The ECM illuminates the service vehicle soon (SVS) lamp when the diagnostic runs and fails.
- The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.

Except 12,000 lbs GVW
- The ECM illuminates the malfunction indicator lamp (MIL) on the second consecutive driving cycle when the diagnostic runs and fails.
- The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Freeze Frame/Failure Records on the second consecutive driving cycle when the diagnostic runs and fails.

Condition for Clearing the MIL/DTC
12,000 lbs GVW
- 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 after the ECM turns OFF the SVS lamp.
- Clear the SVS lamp and the DTC with a scan tool.

Except 12,000 lbs GVW
- The ECM turns OFF the MIL when the diagnostic runs and does not fail.
- 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 emission related diagnostic after the ECM turns OFF the MIL.
- Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
- A charging system problem may set this DTC.
- Jump starting the vehicle or a battery charger may have set this DTC.

DTC P0563
Schematic Reference: Engine Controls Schematics & Starting and Charging Schematics Connector End View Reference: Engine Control Module (ECM) Connector End View

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