Throttle Position (TP) Sensor

SCAN TOOL DIAGNOSIS
The Tech 1 scan tool displays throttle position in volts and percentage of throttle blade opening. The value should display between about 0.3 - 0.9 volts with the throttle closed and ignition "ON," or at idle. Voltage should increase at a steady rate as the throttle is moved toward Wide Open Throttle (WOT) (about 4.6 volts).
The PCM has the ability to auto-zero the Throttle Position (TP) sensor voltage if it is between about 0.3 to 0.9 volt. This means that any voltage in this window will be determined by the PCM to be 0% throttle. A failure in the TP sensor circuit should set a DTC 21 or 22. The Tech 1 has the ability to display the throttle angle and should be 0% when the throttle is closed.