Throttle Position Sensor: Testing and Inspection

THROTTLE POSITION (TP) SENSOR
The TP Sensor is a rotating type variable resistor that rotates with the throttle shaft to sense the throttle valve angle. As the throttle shaft rotates, the resistance of the TP Sensor changes and the ECM detects the throttle valve opening based on the change of the throttle angle.




CIRCUIT DIAGRAM










HARNESS INSPECTION PROCEDURES




SENSOR INSPECTION
1. Disconnect the throttle position sensor connector.
2. Measure resistance between terminal 2 (sensor ground) and terminal 3 (sensor power).

Standard value 0.7-3.0 k Ohm
When idling 2.3-3.4 k Ohm

3. Connect an ohmmeter between terminal 3 (sensor ground) and terminal 1 (sensor output).
4. Operate the throttle valve slowly from the idle position to the full open position and check that the resistance changes smoothly in proportion to the throttle valve opening angle.
5. If the resistance is out of specification, or fails to change smoothly, replace the throttle position sensor.

Tightening torque: 1.5-2.5 Nm (1.1-1.8 ft.lbs.)




USING VOLTMETER







TROUBLESHOOTING PROCEDURES

HINTS:
1. The TPS signal is important in the control of the automatic transaxle. Shift shock and other troubles will occur if the sensor is faulty.
2. If the idle condition or accelerating is abnormal, check the TPS connector. (When the TPS connector is not connected properly, the current data can show that the idle state remains off, though the accelerator pedal is released. And it results in improper idle or accelerating.)
3. Input voltage from throttle position sensor is below 0.1V or above 4.7V when ignition switch is turned on.