Code 22: TPS Signal Volt Low: Notes

Throttle Position Sensor (TPS) provides a voltage signal that changes relative to the throttle valve. Signal voltage will vary from about 1.25 volts at idle to 4.5 volts at WOT. Code 22 will set if TPS voltage is greater than .2 volts for 5 seconds and engine speed is less than 1200 RPM.

1. This test checks to see if Code 22 is the result of a hard failure or an intermittent condition. A Code 22 will set if the engine is running or TPS voltage is below .2 volts (200 mV).
2. This test simulates conditions for a Code 21. If a Code 21 is set, or the "SCAN" tester displays over 4 volts, the ECM and wiring are okay.
3. The "SCAN" tester may not display 12 volts. The important thing is that the ECM recognizes the voltage as over 4 volts, indicating that circuit No. 417 and the ECM are okay.
4. If circuit No. 416 is shorted to ground, there may also be a stored Code 34. If circuit No. 416 is not shorted to ground and a Code 34 is stored, check circuit No. 474 for a short to ground.