Before VIN #343314

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 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.

















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 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 linkage disconnected from manual shaft of A/T assembly. Refer to step 1.
3. If OK on step 2, adjust manual control linkage. Refer to Automatic Transmission/Transaxle; Shift Linkage, A/T.
Shift Linkage





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. Refer to Powertrain Management; Computers and Control Systems.
Computers and Control Systems

6. If NG on step 4, replace PNP switch.

Throttle Position Switch
Closed Throttle Position Switch (idle Position)








- Check continuity between terminals 4 and 5. Refer to TCM Self-Diagnosis Procedure (No Tools). TCM Self-Diagnostic Procedure (No Tools)

Wide Open Throttle Position Switch








- Check continuity between terminals 5 and 6.