Electronic Throttle Actuator: Testing and Inspection

ETC (ELECTRONIC THROTTLE CONTROL) SYSTEM

ETC (Electronic Throttle Control) System Description:

DESCRIPTION
ETC system controls the opening angle of throttle valve to operate throttle valve control, idle speed control, traction control, auto cruise control and so on.

ECM receives accelerator position sensor signals (APS1, APS2) and calculates appropriate throttle opening angle which is used to control the throttle angle of throttle motor. Throttle position sensor integrated into throttle body assembly detects the throttle opening angle (TPS1, TPS2) and sends it to ECM for feedback control.

Circuit Diagram:

Fail-Safe:

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

INSPECTION

ETC MOTOR
1. Disconnect the throttle body assembly connector.
2. Measure resistance as shown below.

Specification : Between pin 3 and 6 : 1.2 - 1.8 at 20 degrees C (68 degrees F)

3. Connect the throttle body assembly connector.

THROTTLE POSITION SENSOR (TPS)
1. Start engine and connect the scan tool to data link connector.




2. Inspect TPS signal output with the scan tool on condition as shown.

Specification :
[TPS #1]
Idle : 0.25 - 0.9 V
Wide open throttle : Min.4.0 V

[TPS #2]
Idle : Min.4.0 V
Wide open throttle : 0.25 - 0.9 V

3. Stop engine and disconnect throttle body assembly connector.




4. Measure resistance as shown.

Specification : Between pin 1 and 2 : 0.88 - 1.63 kOhms