Powertrain Controls - ECM/PCM

DTC 22 Diagnostic Chart:

Throttle Position (TP) Circuit:

CIRCUIT DESCRIPTION
The Throttle Position (TP) sensor provides a voltage signal that changes relative to the throttle blade. Signal voltage will vary from about 0.5 volt at idle to about 4.0 volts at Wide Open Throttle (WOT).
The TP signal is one of the most important inputs used by the Powertrain Control Module (PCM) for fuel control and for most of the PCM control outputs.

CHART TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.
1. DTC 22 will set if:
^ Engine running.
^ TP signal voltage is less than 0.2 volt for 4 second.
2. Simulates DTC 21: (high voltage) If the PCM recognizes the high signal voltage the PCM and wiring are OK.
3. This step determines a poor connection or faulty TP sensor.
4. This simulates a high signal voltage to check for an open in CKT 417.

DIAGNOSTIC AIDS
A TECH 1 scan tool reads throttle position in volts and should read about 0.5 to 1.25 volt with throttle closed and ignition "ON" or at idle. Voltage should increase at a steady rate as throttle is moved toward WOT.
An open or short to ground in CKT 416 or 417 will result in a DTC 22.
Refer to Diagnosis by Symptom/Intermittents
- Intermittent Malfunctions
Scan TP sensor while depressing accelerator pedal with engine stopped and ignition "ON." Display should vary from below 1.25 volt (1250 mV) when throttle was closed, to over 4.0 volts (4000 mV) when throttle is held at Wide Open Throttle (WOT) position.