TCM Self-Diagnosis Does Not Activate

21. TCM Self-diagnosis Does Not Activate (PNP & 3 Position Switches Circuit Checks), and Throttle Position Sensor [Accelerator Pedal Position (APP) Sensor] Circuit Check

SYMPTOM:











A/T check (position) 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.
^ 3 position switch
Detects the A/T selector lever in 3 position 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 inspection for the 3 position switch circuit.

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 T0 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/R) and 2 (B) and between terminals 3 (G/Y) and 4 (PU/W), 5 (P/B), 6 (G), 7 (BR), 8 (G/W) and 9 (GY/R) 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. Refer to "Park/Neutral Position (PNP) Switch Adjustment".
- 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 (PU/W), 27 (P/B), 34 (G), 35 (G/W), 36 (R/B) and ground while moving selector lever through each position.
Voltage:
B : Battery voltage
O : OV
OK or NG OK >> GO TO 6.
NG >> GO T0 4.

4. DETECT MALFUNCTIONING ITEM
Check the following items:








^ Park/neutral position (PNP) switch
- Check continuity between park/neutral position (PNP) switch terminals 1 (G/R) and 2 (B), and between terminals 3 (G/Y) and 4 (PU/W), 5 (P/B), 6 (G), 7 (BR), 8 (G/W) and 9 (GY/R) 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. Refer to "Control Cable Adjustment".
- 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. Refer to "Park/Neutral Position (PNP) Switch Adjustment".
- 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 3 POSITION 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 3 position switch is indicated properly. (Overdrive 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:
^ 3 position switch M34.





- Check for continuity between terminals 1 (L/W) and 2 (B) with selector lever in 3 position.
^ Harness for short or open between meter and 3 position switch (Main harness)
^ Harness of ground circuit for 3 position 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]". P1705
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.

8. CHECK TCM INSPECTION
1. Perform TCM input/output inspection. Refer to "TCM INSPECTION TABLE" Pinout Values and Diagnostic Parameters
OK or NG
OK >> INSPECTION END
NG >> Inspect TCM terminals and related wiring harnesses for damage or loose connections. Repair or replace damaged parts.