P0122

DTC P0122

CIRCUIT DESCRIPTION




The throttle position (TP) sensor is used by the engine control module (ECM) to determine the throttle plate angle for various engine management systems. The TP sensor is a potentiometer type sensor with three circuits:
- A 5-volt reference circuit
- A low reference circuit
- A TP sensor signal circuit

The ECM provides the TP sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Rotation of the TP sensor rotor from the closed throttle position to the wide open throttle (WOT) position provides the ECM with a signal voltage from less than 1 volt to more than 4 volts through the TP sensor signal circuit. If the ECM detects an excessively low signal voltage, DTC P0122 sets.

CONDITIONS FOR RUNNING THE DTC
The engine is running.

CONDITIONS FOR SETTING THE DTC
The ECM detects that the TP sensor voltage is less than 0.20 volt for more 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 - 10:

Steps 11 - 14:

The number below refer to the step number on the diagnostic table.
5. This step determines if the 5 volts supplied by the ECM is available to the sensor. It also determines if the circuit is capable of carrying the necessary amperage.