P2668

DTC P2668

Circuit Description

The fuel indicator lamp (FIL) is located within the headlamp switch assembly. The FIL indicates which fuel system is utilized to operate the vehicle. The FIL illuminates for a few seconds at start up for a bulb check. The FIL remains illuminated while the vehicle is operating on gasoline. The PCM controls the FIL by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the controlled component. The PCM monitors the status of the driver. If the PCM detects an incorrect voltage for the commanded state of the driver, DTC P2668 sets.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

- The control module detects that the commanded state of the driver and the actual state of the control circuit do not match.
- The above condition exists for at least 5 seconds.

Action Taken When the DTC Sets

- The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

Conditions for Clearing the DTC

- A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
- 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.
- Use a scan tool in order to clear the DTC.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2. This step tests if the concern is active. The FIL should turn ON and OFF with the scan tool commands. Repeat the commands as necessary.
5. This step verifies that the control module is providing ground to the FIL.
6. This step tests if a ground is constantly being applied to the FIL.