P0123

Circuit Description
The Accelerator Pedal Position (APP) module provides a voltage signal that changes relative to the Accelerator Pedal Position. There are three sensors located within the APP module that are scaled differently.

Conditions for Running the DTC
Ignition switch in the On position.

Conditions for Setting the DTC
^ The voltage is greater than 4.75 volts on APP 1 sensor.
^ The condition was met for 2 seconds.

Action Taken When the DTC Sets
^ The Service Throttle Soon lamp will not illuminate when one APP DTC sets. The PCM will only illuminate the Service Throttle Soon lamp when multiple APP DTCs set.
^ The PCM records the operating conditions at the time the diagnostic fails. This information stores in the Failure Records.

Conditions for Clearing the MIL/DTC
^ A History DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other emissions related diagnostic.
^ Use of a Scan tool will clear the DTC codes.

Diagnostic Aids
A scan tool reads APP 1 position in volts. It should read about 0.45 to 0.95 volts with the throttle closed and the ignition ON or at idle. Voltage should increase at a steady rate as the throttle is moved toward Wide Open Throttle (WOT). Also, 90% pedal travel is acceptable for correct 0 APP operation. Scan APP 1 sensor while depressing the accelerator pedal with the engine stopped and the ignition ON. Display should vary from about 0.74 volts when the throttle is closed to about 3.7 volts when the throttle is held at the Wide Open Throttle (WOT) position. A P0123 will result if the ground circuit is open or the signal circuit is shorted to voltage.

Test Description
The number(s) below refer to the step number(s) on the Diagnostic Table.
2. This step determines if DTC P0123 is the result of a hard failure or an intermittent condition.
3. This step checks the PCM and wiring.