Throttle Position Sensor: Testing and Inspection

CAUTION: Use a precision voltmeter with a scale of 0.01 volts to inspect or adjust the throttle sensor.

1. Remove the air hose from the throttle body.
2. Disconnect the throttle sensor connector (3-pin).

Throttle Sensor Test Harness:

3. Connect the adapter (SST Mazda Part# 49 G018 901) between the throttle sensor and the wiring harness.
4. Turn the ignition switch on.
5. Make sure that the throttle valve is fully closed.

Throttle Sensor Voltage Testing:

6. Measure BLACK and RED wire voltages. The black wire should be approx. 0 volts and the red wire should be 4.5-5.5 volts.
7. If not as specified check the battery voltage and wiring harness. If these are OK, replace the engine control unit.
8. Record the RED wire voltage.
9. Check the voltage at the BLUE wire and check that it corresponds with the RED voltage received in step 6 by using the following chart.

RED VOLTAGE (VOLTS) BLUE VOLTAGE (VOLTS)

4.50-4.59 0.37-0.54
4.60-4.69 0.38-0.55
4.70-4.79 0.39-0.56
4.80-4.89 0.40-0.57
4.90-4.99 0.40-0.58
5.00-5.09 0.41-0.60
5.10-5.19 0.42-0.61
5.20-5.29 0.43-0.62
5.30-5.39 0.44-0.63
5.40-5.49 0.44-0.64
5.50 0.44-0.66

Throttle Sensor Adjustment:

10. If not as specified, loosen the throttle sensor mounting screws and adjust BLUE wire voltage by rotating the throttle sensor. After adjusting the voltage, tighten the throttle sensor mounting screws and recheck the voltage.

Throttle Valve Fully Open:

11. Hold the throttle valve fully open.
12. Check that Blue and RED wire voltages. Check that the BLUE voltage corresponds with the RED voltage listed in the table below.

RED VOLTAGE (VOLTS) BLUE VOLTAGE (VOLTS)

4.50-4.59 3.58-4.23
4.60-4.69 3.66-4.32
4.70-4.79 3.74-4.41
4.80-4.89 3.82-4.51
4.90-4.99 3.90-4.60
5.00-5.09 3.97-4.70
5.10-5.19 4.05-4.79
5.20-5.29 4.13-4.88
5.30-5.39 4.21-4.98
5.40-5.49 4.29-5.07
5.50 4.29-5.17

13. If not as specified, replace the throttle sensor.
14. Turn the ignition switch off.
15. Disconnect the Self Tester and reconnect the throttle sensor connector.
16. Disconnect the negative battery terminal and depress the brake pedal for at least 5 seconds to eliminate the control unit malfunction memory created during inspection.