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 sensor he throttle valve angle. As the throttle shaft rotates, the throttle angle 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 kOhms
When idling: 2.3 - 3.4 kOhms

3. Connect a pointer type 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 with 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 (15 - 25 kg.cm, 1.1 - 1.8 lb.ft)


TROUBLESHOOTING PROCEDURES




MALFUNCTION SYMPTOM
Input voltage from throttle position sensor is below 0.1V or above 4.7V when ignition switch is turned on.

TROUBLESHOOTING HINTS
1. The TP Sensor signal is important in the control of 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 is remain off, though the accelerator pedal is released. And it results the improper idle or accelerating.)


USING VOLTMETER