Throttle Position Sensor: Testing and Inspection

INSPECTION

FUNCTION AND OPERATION PRINCIPLE
ETC (Electronic Throttle Control) system is electronically controlled throttle device which controls the throttle valve. It consists of ETC motor, throttle body and throttle position sensor (TPS). A mechanical throttle control system receives a driver's intention via a wire cable between the accelerator and the throttle valve, while this ETC system does the signal from the Accelerator Position Sensor (APS) installed on the accelerator pedal. After the PCM receives the APS signal and calculates the throttle opening angle, it activates the throttle valve by using the ETC motor. Additionally, it can materialize cruise control function without any special devices.





COMPONENTS





SPECIFICATION
[THROTTLE POSITION SENSOR]














[ETC MOTOR]






SCHEMATIC DIAGRAM





FAIL-SAFE MODE






NOTE:
When throttle value is stuck at 5°, engine speed is limited at below 1,500rpm and vehicle speed at maximum 40 - 50 km/h (25 - 31mph).

COMPONENT INSPECTION

THROTTLE POSITION SENSOR (TPS)

1. Connect a scantool on the Data Link Connector (DLC).
2. Start engine and check output voltages of TPS 1 and 2 at C.T and W.O.T.

Specification: Refer to SPECIFICATION.


3. Turn ignition switch OFF and disconnect the scantool from the DLC.
4. Disconnect ETC module connector and measure resistance between ETC module terminals 1 and 2.

Specification: Refer to SPECIFICATION.


ETC MOTOR
1. Disconnect ETC module connector and measure resistance between ETC module terminals 3 and 6.

Specification: Refer to SPECIFICATION.


ETC SYSTEM INITIALIZATION
When ignition switch is turned from OFF to ON, ETC system learns the throttle angle in 1 sec.
1. Throttle valve moves from limp-home position to close position.
2. And then, it opens to about 15° and moves to limp-home position.