P0651

DTC P0651

Circuit Description

The engine control module (ECM) provides a 5-volt reference to the following sensors:

^ The throttle position (TP) sensors 1 and 2
^ The accelerator pedal position (APP) sensor 2
^ The fuel level sensor 1
^ The air conditioning (A/C) refrigerant
^ The fuel tank pressure (FTP) sensor
^ The engine oil pressure (EOP) sensor

The ECM monitors voltage on the 5-volt reference circuit. If the ECM detects that the voltage on the 5-volt reference circuit is outside a calibrated range, DTC P0651 will set.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

^ The ECM detects a voltage that is out of range on the 5-volt reference 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

The number below refers to the step number on the diagnostic table.

5. This step will determine if the throttle body is at fault, or if another device or circuit condition is at fault.