DTC P0656 Fuel Level Output Circuit.

The engine control module (ECM) creates the fuel gage output signal by pulsing the circuit to ground. The ECM monitors the voltage on the fuel gage output circuit. If the ECM determines that the voltage is out of the normal operating range, a DTC sets.

The engine is running.

The ECM detects an open, short to ground, or a short to voltage on fuel gage output circuit.

DTC P0656 is a Type C DTC.

DTC P0656 is a Type C DTC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Special Tools

J 33431-C Signal Generator and Instrument Panel Tester

With the engine idling for 1 minute, observe the DTC information with a scan tool. DTC P0656 should not set.

1. Ignition ON, observe the DTC info with a scan tool. Verify that DTC P1668 is not also set.

⇒	If DTC P1668 is also set, test the ignition 1 voltage circuit and the ground circuit of the instrument panel cluster (IPC) for an open, short to ground, or high resistance.

⇒	If the circuits/connections test normal, replace the IPC.

2. Ignition OFF, disconnect the harness connector of the ECM.
3. Install the J 33431-C between the output circuit of the fuel gage and the negative terminal of the battery.
4. Ignition ON, set the J 33431-C to generate a speedometer signal. Verify the fuel gage operation.

⇒	If the fuel gage does not operate, test the output circuit of the fuel gage for an open, short to ground, short to voltage, or a high resistance. If the circuit/connections test normal, replace the fuel gage.

5. If all circuits/connections test normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.