Throttle Full Close Switch: Testing and Inspection

CLOSED THROTTLE POSITION SWITCH

OPERATION
- The closed throttle position switch functions to convert (to HIGH/LOW-level voltage) data as to whether the accelerator is depressed or released, and to input that voltage (as signals) to the engine control module. The engine control module, based upon those signals, regulates the idle air control motor.
- Voltage within the engine control module is applied, by way of the resistance, to the closed throttle position switch. When the foot is taken off the accelerator, the closed throttle position switch is switched ON, so the current is grounded. As result, the closed throttle position switch terminal voltage changes from HIGH to LOW level.

TROUBLESHOOTING HINTS
If there is an abnormal condition of the closed throttle position switch output even though the results of the checking of the closed throttle position switch harness and of the component itself indicate a normal condition, the cause is probably one of the following.
1. Incorrect adjustment of the accelerator cable or the cruise-control cable.
2. Incorrect adjustment of the fixed Speed Adjustment Screw (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. If the closed throttle position switch turns buck 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





STEP 1. Check for an open or short-circuit between the closed throttle position switch and the engine control module.
- Engine control module connector: Disconnected
- Throttle position sensor connector: Disconnected

OK: GO TO STEP 2
NG: Repair the harness. (A2 - 87)





STEP 2. Check for continuity in the ground circuit.
- Throttle position sensor connector: Disconnected

OK: GO TO STEP 3
NG: Repair the harness. (A1 - 92)





STEP 3. Measure the power supply voltage of the closed throttle position switch.
- Throttle position sensor connector: Disconnected
- Engine control module connector: Connected
- Ignition switch: ON

Voltage (V): 4 or higher

OK: STOP
NG: Replace the engine control module.





SENSOR INSPECTION
1. With the accelerator pedal released, check that the throttle valve lever or the fixed SAS is pushed.

NOTE:
If it is not pushed, adjust the fixed SAS.

2. Disconnect the throttle position sensor connector.








3. Check for continuity between throttle position sensor connector terminal (1) (sensor ground) and terminal (2) (closed throttle position switch).

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

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