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





- Park/neutral position (PNP) switch
The park/neutral (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

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

COMPONENT INSPECTION








Overdrive Control Switch
- Check continuity between terminals 5 and 6.
Continuity:
Switch position ON: No
Switch position OFF: Yes

PNP Switch








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.
- To adjust closed throttle position switch, refer to Powertrain Management; Computers and Control Systems.
Computers and Control Systems









Wide Open Throttle Position Switch
- Check continuity between terminals 4 and 5.