P0123
CIRCUIT DESCRIPTIONThe throttle position (TP) sensors 1 and 2 are located within the throttle body assembly. Each sensor has its own 5-volt reference, low reference, and 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 the PCM detects a fault with both TP 1 and TP 2 the diagnostic trouble code (DTC) sets.
CONDITIONS FOR RUNNING THE DTC
- The ignition switch is in the crank or run position.
- DTC P1635 is not set.
- The ignition voltage is more than 5.23 volts.
CONDITIONS FOR SETTING THE DTC
The TP sensor 1 and 2 voltages are not within a calibrated range.
ACTION TAKEN WHEN THE DTC SETS
- The PCM will illuminate the malfunction indicator lamp (MIL) during the first trip in which the diagnostic runs and fails.
- The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.
CONDITIONS FOR CLEARING THE MIL/DTC
- The PCM will turn OFF the 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.
DIAGNOSTIC AIDS
The DTC indicates 2 separate faults, one fault with TP sensor 1 and one fault with TP sensor 2. The DTC P1120 diagnostic table along with the DTC P1220 diagnostic table may need to be followed to find both faults.
TEST
