Throttle Full Close Switch: Testing and Inspection

OPERATION
- The closed throttle position switch senses whether the accelerator pedal is depressed or not, converts it into high/low voltage and inputs the voltage to the engine control module, which then controls the idle air control motor based on the input signal.
- The voltage in the engine control module is applied to the closed throttle position switch through a resistor. When the accelerator pedal is released, the closed throttle position switch is turned on to conduct the voltage to ground. This causes the closed throttle position switch terminal voltage to go low from high.

TROUBLESHOOTING HINTS
If the closed throttle position switch harness and individual part check results are normal but the closed throttle position switch output is abnormal, the following troubles are suspected.
(1) Poorly adjusted accelerator cable or auto-cruise control cable
(2) Poorly adjusted fixed SAS

INSPECTION





Using Scan Tool

NOTE:
*: The closed throttle position switch normally turns off when the voltage of the throttle position sensor is 50 - 100 mV higher than the voltage at the idle position. It the closed throttle position switch turns back on after the throttle position sensor voltage has risen by 100 mV and the throttle valve has opened, the closed throttle position switch and the throttle position sensor need to be adjusted.

HARNESS INSPECTION





Measure the power supply voltage of the closed throttle position switch.
- Connector: Disconnected
- Ignition switch: ON
Voltage (V): 4 or more
OK: GO TO STEP 2
NG: Repair the harness. (A3-79)





Check for continuity of the ground circuit.
- Connector: Disconnected
OK: STOP
NG: Repair the harness. (A4-49)

CLOSED THROTTLE POSITION SWITCH CHECK
(1) With the accelerator pedal released, check to be sure that the throttle valve lever or the fixed SAS is pushed.

NOTE: If it is not pushed, adjust the fixed SAS. Refer to Idle Speed.





(2) Disconnect the throttle position sensor connector.








(3) Check the continuity across the throttle position sensor connector terminal (4) (Sensor ground) and (3) (Closed throttle position switch).

NOTE: If there is no continuity when the accelerator pedal is returned, loosen the throttle-position sensor installation screw; then, after turning all the way in the counterclockwise direction, check again.

(4) Replace the throttle-position sensor (closed throttle position switch incorporated) if there is a malfunction.