P0123
DTC P0123
Circuit Description
The throttle position (TP) sensors 1 and 2 are located within the throttle body assembly. Each sensor has the following circuits:
- 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 the throttle plate movement. The TP sensor 1 signal voltage at closed throttle is near the 5-volt reference circuit and decreases as the throttle plate is opened. The TP sensor 2 signal voltage at closed throttle is near the low reference circuit and increases as the throttle plate is opened. If the PCM detects that the TP sensor 1 signal voltage is more than the predicted range, DTC P0123 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
The PCM detects that the TP sensor 1 voltage is more than 4.67 volts.
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 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.
Step 1 - 5:
Step 6 - 12:
