TCM Self-Diagnosis Does Not Activate

21. TCM Self-diagnosis Does Not Activate {Park/neutral Position (PNP), Overdrive Control and Throttle Position Sensor [Accelerator Pedal Position (APP) Sensor] Switches Circuit Checks}

SYMPTOM: O/D OFF indicator lamp does not come on in TCM self-diagnostic procedure even if 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 sensor [accelerator pedal position (APP) sensor]
The throttle position sensor [accelerator pedal position (APP) sensor] is part of the system that controls the throttle position. This system also uses an electric throttle control actuator, which consists of a throttle control motor and throttle position sensors. Accelerator pedal position signal is sent to the ECM.

DIAGNOSTIC PROCEDURE

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

1. CHECK PARK/NEUTRAL POSITION (PNP) SWITCH CIRCUIT (WITH CONSULT-II)
With CONSULT-II
1. Turn ignition switch to ON position. (Do not start engine.)
2. Select "TCM INPUT SIGNALS" in "DATA MONITOR" mode for"A/T" with CONSULT-II.





3. Read out P/N, R, D, 2 and 1 position switches moving selector lever to each position. Check that the signal of the selector lever position is indicated properly.
OK or NG
OK >> GO TO 5.
NG >>GO TO 2.

2. DETECT MALFUNCTIONING ITEM








Check the following items:
- Park/neutral position (PNP) switch
- Check continuity between park/neutral position (PNP) switch F29 terminals 1 (G/OR) and 2 (B) and between terminals 3 (Y) and 4 (OR), 5 (L), 6 (W/G), 7 (BR/W), 8 G/W), 9 (G) while moving manual shaft through each position.
- If NG, check again with manual control cable disconnected from manual shaft of A/T assembly. Refer to step a.
- If OK on step b, adjust manual control cable.
- If NG on step b, remove park/neutral position (PNP) switch from A/T and check continuity of park/neutral position (PNP) switch terminals. Refer to step a.
- If OK on step d, adjust park/neutral position (PNP) switch.
- If NG on step d, replace park/neutral position (PNP) switch.
- Harness for short or open between ignition switch and park/neutral position (PNP) switch (Main harness)
- Harness for short or open between park/neutral position (PNP) switch and TCM (Main harness)
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.

3. CHECK PARK/NEUTRAL POSITION (PNP) SWITCH CIRCUIT (WITHOUT CONSULT-II)
Without CONSULT-II
1. Turn ignition switch to ON position. (Do not start engine.)








2. Check voltage between TCM terminals 26 (OR), 27 (L), 34 (W/G), 35 (G/W), 36 (BR/W) and ground while moving selector lever through each position.
Voltage:
B: Battery voltage
0: 0V
OK or NG
OK >> GO TO 6.
NG >>GO TO 4.

4. DETECT MALFUNCTIONING ITEM
Check the following items:








- Park/neutral position (PNP) switch
- Check continuity between park/neutral position (PNP) switch F29 terminals 1 (G/OR) and 2 (B) and between terminals 3 (Y) and 4 (OR), 5 (L), 6 (W/G), 7 (BR/W), 8 G/W), 9 (G) while moving manual shaft through each position.
- If NG, check again with manual control cable disconnected from manual shaft of A/T assembly. Refer to step a.
- If OK on step b, adjust manual control cable.
- If NG on step b, remove park/neutral position (PNP) switch from A/T and check continuity of park/neutral position (PNP) switch terminals. Refer to step a.
- If OK on step d, adjust park/neutral position (PNP) switch.
- If NG on step d, replace park/neutral position (PNP) switch. Harness for short or open between ignition switch and park/neutral position (PNP) switch (Main harness) Harness for short or open between park/neutral position (PNP) switch and TCM (Main harness)
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.

5. CHECK OVERDRIVE CONTROL SWITCH CIRCUIT (WITH CONSULT-II)
With CONSULT-II
1. Turn ignition switch to ON position. (Do not start engine.)
2. Select "TCM INPUT SIGNALS" in "DATA MONITOR" mode for "A/T" with CONSULT-II.





3. Read out "OVERDRIVE SW". Check the signal of the overdrive control switch is indicated properly. (Overdrive control switch "ON" displayed on CONSULT-II means overdrive "OFF".)
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.

6. DETECT MALFUNCTIONING ITEM





Check the following items:
- Overdrive control switch M44.
- Check continuity between two terminals.
- Harness for short or open between TCM and overdrive control switch (Main harness)
- Harness of ground circuit for overdrive control switch (Main harness) for short or open
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.

7. CHECK THROTTLE POSITION SENSOR [ACCELERATOR PEDAL POSITION (APP) SENSOR]
- Perform throttle position sensor [accelerator pedal position (APP) sensor] inspection. Refer to "DTC P1705 THROTTLE POSITION SENSOR [ACCELERATOR PEDAL POSITION (APP) SENSOR]".
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.

8. CHECK TCM INSPECTION
1. Perform TCM input/output inspection.
OK or NG
OK >> INSPECTION END.
NG >> Inspect TCM terminals and related wiring harnesses for damage or loose connections. Repair or replace damaged parts.