P0653

DTC P0653

CIRCUIT DESCRIPTION
The engine control module (ECM) provides 5 volts reference voltage through the reference circuit 2 to the accelerator pedal position (APP) sensor 2. The ECM monitors the voltage on the 5 volts reference circuit 2. If the ECM detects the voltage is excessively high, this DTC will set.

Condition for Running the DTC
- DTC P0652 is not set.
- The battery voltage is between 10-16 volts.
- The ignition switch is ON.

Condition for Setting the DTC
- The ECM detects that the 5 volts reference circuit 2 voltage is more than 5.5 volts.

Action Taken When the DTC Sets
- 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
- The ECM turns OFF the MIL after 3 consecutive driving cycles when the diagnostic runs and does not fail. (12,000 lbs GVW)
- The ECM turns OFF the MIL when the diagnostic runs and does not fail. (Except 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 emission related diagnostic after the ECM turns OFF the MIL.
- Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
If an intermittent condition is suspected, the following may cause an intermittent:
- Misrouted harness
- Rubbed through wire insulation

Check for the following conditions:
- Damaged harness: Inspect the wiring harness for damage. If the harness appears to be OK, observe the "5 Volt Reference 2" display on the scan tool with ignition ON and engine OFF while moving connectors and the wiring harness related to the sensor. A change in the display will indicate the location of the fault.

DTC P0653
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views or Engine Control Module (ECM) Connector End Views

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