Throttle Position Sensors and Solenoids
TESTING THE THROTTLE POSITION SENSOR (TPS)
The throttle position sensor is used to tell the engine computer the position of the throttle valve.
If your engine light is on, it could be telling you the throttle position sensor is bad.
To test the throttle position sensor (TPS), you will need a voltmeter.
Disconnect the connector from the ECM (engine control module) to the TPS (throttle position sensor). This is the connector to the TPS.
The connector will have three terminals. One is negative, one is the signal and one is the reference terminal. The center terminal is probably the negative terminal.
Connect the volt meter ground to the battery ground.
Connect the voltmeter positive lead to one of the non negative terminals. One of the terminals is the reference terminal and should read 5 volts. Anything below 5 volts would indicate you have the signal terminal, not the reference. In this case go to the other terminal.
A 5 volt reading from the reference terminal indicates the power feed from the ECM is ok.
Plug the connector back into the throttle position sensor.
Connect the positive voltmeter lead to the signal wire of the connector (while connected to TPS).
Slowly open the throttle valve. If you get a fluctuation of voltage as you move the throttle, then replace the throttle position censor.
Order your throttle Position Sensor below.
Part Number 1209-1
Part Number TPS051
Part Number TPS100
Part Number TPS054
1988-93 GMC Truck, Oldsmobile, Pontiac
Part Number TPS101
Part Number 200-1001
Part Number 66-462