Throttle Position Sensor (TPS)

Operation

The throttle-position sensor functions to convert the degree of opening of the throttle valve to voltage, and to input that voltage (as signals) to the engine control module. The engine control module, based upon those signals, then regulates the amount of fuel injection, etc.

The 5V power supply within the engine control module is supplied to the throttle-position sensor, after which it passes through the resistance within the sensor and is grounded at the engine control module.

When the throttle valve shaft is rotated all the way from the idling position to the fully open position, the resistance between the throttle position sensor's variable-resistance terminal and the ground terminal also increases in accordance with that rotation, and, as a result, the voltage of the throttle-position sensor's variable-resistance terminal also becomes higher in accordance with that rotation.




Inspection




Harness Inspection

Troubleshooting Hints

Hint 1: The signals of the throttle-position sensor are more important tor control of the automatic transaxle than for control of the engine; shifting "impact shocks" are produced if there is a malfunction of the throttle-position sensor.

Hint 2: If the voltage of the throttle position sensor deviates from the standard value, check once again after making the throttle position sensor adjustment. In addition, if there are any indications that the fixed SAS has been moved, adjust the fixed SAS.



Sensor Inspection

(1) Disconnect the throttle position sensor connector.





(2) Measure resistance between terminal 2 (sensor ground) and terminal 3 (sensor power).

Standard value: 3.5-6.5 k/Ohms

(3) Connect a pointer type ohmmeter between terminal 2 (sensor ground) and terminal 4 (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.

Throttle position sensor installation torque: 1.5-2.5 Nm (1.1-1.8 ft.lbs.)