Code 23, Throttle Position Sensor MISADJUSTED: Notes

The Throttle Position Sensor (TPS), a variable mechanical resistor, informs ECM of throttle opening. The TPS, connected to a 5-volt reference signal, has a high resistance value at closed throttle. At wide open throttle, TPS resistance is at its lowest, and output to ECM will be close to 5 volts. Code 23 indicates ECM has noted that voltage, at terminal A2, is not .25-1.35 volts for at least 30 seconds, with engine speed at 550-650 RPM.

1. This confirms Code 23 fault is present.
2. This test determines if sensor signal line is shorted to ground.
3. See THROTTLE POSITION SENSOR in N - REMOVE/INSTALL/OHAUL article.