P0651
DTC P0651
Circuit Description
The powertrain control module (PCM) uses the 5-volt reference circuit as a sensor feed to the following sensors:
* The manifold absolute pressure (MAP) sensor
* The throttle position sensor 2
* The accelerator pedal position sensor 1
The PCM monitors the voltage on the 5-volt reference circuit. If the voltage is out of tolerance, the PCM will set DTC P0651.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0651 5-Volt Reference 2 Circuit
Conditions for Running the DTC
* DTCs P0601, P0602, P0604, P0606, P1621, and P2610 are not set.
* The ignition is in unlock, accessory, run, or crank mode.
* The ignition voltage is greater than 5.2 volts.
* DTC P0651 runs continuously when the above conditions are met.
Conditions for Setting the DTC
* The PCM detects a voltage out of tolerance condition on the 5-volt reference circuit.
* The above condition is present for one 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
