P0641
DTC P0641
Circuit Description
The powertrain control module (PCM) provides a 5-volt reference to the following sensors:
* The throttle position (TP) sensor 1
* The accelerator pedal position (APP) sensor 2
* The engine cooling fan speed sensor
* The AC pressure sensor
* The fuel tank pressure (FTP) sensor
* The oil pressure sensor (OPS)
The PCM monitors voltage on the 5-volt reference circuit. If the voltage is higher or lower than required, DTC P0641 will set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0641 5-Volt Reference 1 Circuit
Conditions for Running the DTC
* The ignition is in unlock/accessory, run, or crank position.
* DTC P0601, P0602, P0604, P0606, P060D, P060E, P1621 are not set.
Conditions for Setting the DTC
* The PCM detects a voltage that is higher or lower than required on the 5-volt reference circuit.
* The above condition is present for 1 second.
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
