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 PARK/NEUTRAL POSITION (PNP) SWITCH CIRCUIT (WITH CONSULT-II)





2: DETECT MALFUNCTIONING ITEM





3: CHECK PARK/NEUTRAL POSITION (PNP) SWITCH CIRCUIT (WITHOUT CONSULT-II)





4: DETECT MALFUNCTIONING ITEM





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





6: DETECT MALFUNCTIONING ITEM





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





8: DETECT MALFUNCTIONING ITEM





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





10: DETECT MALFUNCTIONING ITEM





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





12: DETECT MALFUNCTIONING ITEM





13: CHECK DTC





14: CHECK TCM INSPECTION

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