P0120
DTC P0120CIRCUIT DESCRIPTION
The throttle position (TP) sensors 1 and 2 are located within the throttle body assembly. Each sensor has the following components:
- A 5-volt reference circuit
- A low reference circuit
- A signal circuit
This provides the powertrain control module (PCM) with a signal voltage proportional to throttle plate movement. TP sensor 1 signal voltage at closed throttle is near the 5-volt reference and decreases as the throttle plate is opened. TP sensor 2 signal voltage at closed throttle is near the low reference and increases as the throttle plate is opened. When TP sensor 1 signal voltage is not within the predicted range, this code sets.
CONDITIONS FOR RUNNING THE DTC
- The ignition switch is in the crank or run position.
- DTC P0641 is not set.
- The ignition voltage is greater than 5.23 volts.
CONDITIONS FOR SETTING THE DTC
TP sensor 1 voltage is less than 0.27 volts or more than 4.67 volts as observed on the scan tool.
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 and/or the Failure Records.
- The control module commands the TAC system to operate in the Reduced Engine Power mode.
- A message center or an indicator displays Reduced Engine Power.
- Under certain conditions the control module commands the engine OFF.
CONDITIONS FOR CLEARING THE MIL/DTC
- The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic runs and passes.
- The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
- The DTC can be cleared by using a scan tool.
TEST
