Powertrain Controls - ECM/PCM

DTC 22 Accelerator Pedal Position (APP) 1 Circuit Low:

Accelerator Pedal Position (APP):

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

DIAGNOSTIC TROUBLE CODE (DTC) 22 WILL SET WHEN
Voltage is less than 0.25 volt for 2 seconds on APP 1 sensor.

ACTION TAKEN (PCM will default to)
The input from APP 1 sensor is ignored. A current and history DTC will set but it will not turn "ON" the "Service Throttle Soon" lamp. The throttle will operate normally as long as there is only one sensor malfunctioning. If two different APP sensors have a malfunction, the "Service Throttle Soon" lamp will light and the Powertrain Control Module (PCM) will limit power. If three APP sensors have a malfunction present, the "Service Throttle Soon" lamp will light and the PCM will only allow the engine to operate at idle.

DTC 22 WILL CLEAR WHEN
The fault condition(s) no longer exist and the ignition switch is cycled "OFF" then "ON."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step determines if DTC 22 is the result of a hard failure or an intermittent condition.
2. This step checks the PCM and wiring.
3. This step will determine if there is a faulty connection or sensor.
4. This step will check the ground circuit.

DIAGNOSTIC AIDS
A scan tool reads APP 1 position in volts. Should read about 0.45 to 0.95 volt with throttle closed and ignition "ON" or at idle. Voltage should increase at a steady rate as throttle is moved toward Wide Open Throttle (WOT).
Also, 90% pedal travel is acceptable for correct APP operation.
Scan APP 1 sensor while depressing accelerator pedal with engine stopped and ignition "ON." Display should vary from about 0.74 volt when throttle is closed to about 3.7 volts when throttle is held at Wide Open Throttle (WOT) position. A DTC 22 will result if circuit is open.