DTC 22

DIAGNOSTIC CHART





WIRING DIAGRAM

INSPECTION PROCEDURE

Circuit Description:
The TP Sensor provides a voltage signal that changes relative to the throttle valve. Signal voltage will vary from about .5 at idle to about 5 volts at Wide Open Throttle (WOT).
The TP Sensor signal is one of the most important inputs used by the Engine Control Module (ECM) for fuel control and for most of the ECM control outputs.

Test Description:
Numbers below refer to circled numbers on the diagnostic chart.
1. DTC 22 will set if:
- Engine is running
- TP Sensor signal voltage is less than about .2 volt for 2 seconds.
2. Simulates DTC 21: (high voltage) If the ECM recognizes the high signal voltage then the ECM and wiring are OK.
3. This simulates a high signal voltage to check for an open in CKT C13. The "Scan" tool will not read up to 12 volts, but what is important is that the ECM recognizes the signal on CKT C13.
4. There should be 5 volts at terminal "C" if measured with a DVM when ignition is "ON".

Diagnostic Aids:
A "Scan" tool reads throttle position in volts. Should read less than 1.25 volts 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 CKTs C14 or C13 will result in a DTC 22.
If a DTC 22 is also set check CKT C14 carefully for open or short to ground.
Refer to "Intermittents" in "Symptoms" or AUTOMATIC TRANSMISSIONS.