Throttle Position Sensor: Testing and Inspection
SCAN TOOL TESTINGThe scan tool displays Throttle Position (TP) in volts. The voltage should display between 0.23 and 0.59, with throttle closed and ignition "ON," or at idle. Voltage should increase at a steady rate as throttle is moved toward Wide Open Throttle (WOT) about 4.6 volts.
The ECM has the ability to Auto-Zero the TP sensor voltage if it is between 0.23 and 0.59 volt. This means that any closed throttle voltage between 0.23 and 0.59 volt will be determined by the ECM to be 0% throttle. The Tech 1 has the ability to display the throttle angle, and should display 0% when the throttle is closed. A failure in the TP sensor circuit should set a DTC 21 or 22. Testing and Inspection