TCM Self-Diagnosis Does Not Activate

TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches Circuit Checks)
SYMPTOM: O/D OFF indicator lamp does not come on in TCM self-diagnostic procedure even the lamp circuit is good.

DESCRIPTION





- PNP switch
The PNP switch assembly includes a transmission range switch. The transmission range 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 throttle 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.

DIAGNOSTIC PROCEDURE





1: CHECK PNP SWITCH CIRCUIT (WITH CONSULT-II)





2: CHECK PNP SWITCH CIRCUIT (WITHOUT CONSULT-II)





3: CHECK OVERDRIVE CONTROL SWITCH CIRCUIT (WITH CONSULT-II)





4: CHECK OVERDRIVE CONTROL SWITCH CIRCUIT (WITHOUT CONSULT-II)





5: CHECK THROTTLE POSITION SWITCH CIRCUIT (WITH CONSULT-II)





6: CHECK THROTTLE POSITION SWITCH CIRCUIT (WITHOUT CONSULT-II)





7: CHECK DTC

COMPONENT INSPECTION





Overdrive Control Switch





- Check continuity between terminals 1 and 2.

PNP Switch





Location: Terminals





Table





Location: PNP

1. Check continuity between terminals 1 and 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 cable disconnected from manual shaft of A/T assembly. Refer to step 1.
3. If OK on step 2, adjust manual control cable.
4. If NG on step 2, remove PNP switch from A/T and check continuity of PNP switch terminals. Refer to step 1.
5. If OK on step 4, adjust PNP switch.
6. If NG on step 4, replace PNP switch.





Throttle Position Switch
Closed throttle position switch (idle position)





- Check continuity between terminals 5 and 6. Refer to "Preparation", "TCM Self-diagnostic Procedure (No Tools)".
- To adjust closed throttle position switch, refer to Powertrain Management; Computers and Control Systems.





Wide Open Throttle Position Switch





- Check continuity between terminals 4 and 5.