Throttle Position Sensor: Testing and Inspection

Fig. 5 Checking Throttle Sensor Terminal Voltage:

TERMINAL VOLTAGE
1. Remove rubber boot from connector Fig. 5.
2. Turn ignition switch on.

Fig. 74 Throttle sensor connector terminal identification. Turbo:

3. Check voltage between each terminal and ground, then open throttle valve and check voltage between each terminal and ground, Fig. 74. Voltage should be .4---.6 volt at terminal A with throttle valve closed, approximately 4.5 volts at terminal A with throttle valve open, less than 1.5 volts at terminal B regardless of throttle valve position, 4.5---5.5 volts at terminal C regardless of throttle valve position, less than 1.5 volts at terminal D with throttle valve closed and approximately 12 volts at terminal D with throttle valve open.
4. If voltage is incorrect at terminal D only, check throttle sensor setting.
5. If voltage is incorrect at terminals other than D, check resistances of throttle sensor, terminals 2A, 2C, 2E and 1G of EGI control unit and the wiring harness.
6. Install rubber boot to connector.

Fig. 6 Inserting Thickness Gauge, Throttle Sensor:

TESTING TERMINAL RESISTANCE
7. Check throttle sensor setting, if necessary, as follows:
a. Disconnect connector from sensor.
b. Install a .016 inch thick gauge between lever and throttle adjusting screw Fig. 6.

Fig. 8 Checking Throttle Sensor Terminal Resistance:

c. Using ohmmeter, Fig. 8, check for continuity between terminals B and D.
d. Replace thickness gauge with one of .022 inch.
e. Check for no continuity between terminals B and D.

Fig. 7 Rotating Throttle Sensor:

f. If continuity is not as described, adjust sensor by turning sensor Fig. 7, then repeat steps b through e.
8. Check resistance between terminals, then open throttle valve fully and check resistance between terminals. Resistance between terminals A and B should be approximately 500 ohms with throttle valve closed and approximately 4.5k ohms with throttle valve open and resistance between terminals B and C should be 4---6k ohms regardless of position of throttle valve.