P0641

DTC P0641

CIRCUIT DESCRIPTION
- The engine control module (ECM) provides 5-volts to the following sensors:
- The accelerator pedal position (APP) sensor 1
- The APP sensor 3
- The fuel rail pressure (FRP) sensor
- The engine oil pressure (EOP) sensor
- These 5-volt reference circuits are independent of each other outside the ECM, but are bussed together inside the ECM. Therefore, a circuit condition on one sensor 5-volt reference circuit may affect the other sensor 5-volt reference circuits. The ECM monitors the voltage on the 5-volt reference circuit. If the ECM detects that the voltage is out of tolerance, DTC P0641 sets.

CONDITIONS FOR RUNNING THE DTC
The engine is running.

CONDITIONS FOR SETTING THE DTC
- The ECM detects a voltage out of tolerance condition on the 5-volt reference A circuit.
- The above condition is present for longer than 10 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 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 DESCRIPTION

Steps 1-2:

Steps 3-6:

Steps 7-10:

Steps 11-12:

The number below refers to the step number on the diagnostic table.
8. A short to the transmission control module (TCM) MIL request may not show up on the scan tool as skewed sensor readings. The TCM momentarily grounds the circuit as a test, and the test is just long enough to set this DTC.