Procedure 21

SYMPTOM:
O/D OFF indicator lamp does not come on in TCM self-diagnostic procedure even the lamp circuit is good.

DESCRIPTION
- Inhibitor switch
Detects the selector lever position and sends a signal to the TCM.
- Overdrive control switch
Detects the overdrive control switch position (ON or OFF) and sends a signal to the TCM.
- Throttle position switch
Consists of a wide-open throttle position switch and a closed throttle position switch.
The wide-open position switch sends a signal to the TCM when the throttle valve is open at least 1/2 of the full throttle position. The closed throttle position switch sends a signal to the TCM when the throttle valve is fully closed.

Steps 1 - 2:

Steps 3 - 4:

Steps 5 - 6:

DIAGNOSTIC PROCEDURE
NOTE: The diagnostic procedure includes inspections for the overdrive control and throttle position switch circuits.

COMPONENT INSPECTION




Overdrive Control Switch
- Check continuity between two terminals.

Continuity:
Switch position "ON":
No
Switch position "OFF":
Yes


Inhibitor Switch










1. Check continuity between terminals 1 arid 2 and between terminals 3 and 4, 5, 6, 7, 8, 9 while moving manual shaft through each position.




2. If NG, check again with manual control linkage disconnected from manual shaft of A/T assembly. Refer to step 1.
3. If OK on step 2, adjust manual control linkage.




4. If NG on step 2, remove inhibitor switch from A/T and check continuity of inhibitor switch terminals. Refer to step 1.
5. If OK on step 4, adjust inhibitor switch.
6. If NG on step 4, replace inhibitor switch.

Throttle Position Switch







Closed Throttle Position Switch (Idle Position)
- Check continuity between terminals 1 and 2.







Wide Open Throttle Position Switch
- Check continuity between terminals 2 and 3.