P1208

DTC P1208

Circuit Description

The fuel injector control module (FICM) monitors the fuel rail pressure (FRP) sensor voltage, and the fuel rail temperature (FRT) sensor voltage. The FICM communicates the data to the PCM by dedicated pulse width modulated (PWM) circuits.

This DTC sets when the rail temperature output PWM signal is not received by the PCM.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

- The fuel rail temperature output PWM signal is not received by the PCM.
- The condition exists for at least 5 seconds.

Action Taken When the DTC Sets

- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module switches over to gasoline fuel operation.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that 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.
- Clear the MIL and the DTC with a scan tool.

Test Descriptions

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

2. This step determines if the condition is present.
3. If any of the listed DTCs are set, diagnose those DTCs first.
5. This step tests the signal circuit of the FRT sensor. The DMM should display 5 volts.
7. This step tests the low reference circuit of the FRT sensor. An open FRT sensor low reference circuit may cause this DTC to set.
8. This step determines if the FICM, PCM, and the rail temperature output PWM circuit are OK. If the temperature parameter changes when the FRT signal circuit is grounded, the FICM, PCM, and wiring are OK. Repeat the procedure as necessary in order to verify correct operation of the FICM, PCM, and the rail temperature output PWM circuit.
9. This step verifies that the FICM is supplying the correct output voltage. The open circuit voltage should be 5.0 volts.