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 2.
NG >> Check the following items:
^ PNP switch (Refer to "DTC P0705 PARK/ NEUTRAL POSITION (PNP) SWITCH"
^ Harness for short or open between ignition switch and PNP switch (Main harness)
^ Harness for short or open between PNP switch and TCM (Main harness)

2. 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 3.
NG >> Check the following items:
^ Overdrive control switch
^ Harness for short or open between TCM and over drive control switch (Main harness)
^ Harness of ground for overdrive control switch Main harness) for short or open

3. 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 4.
NG >> Repair or replace damaged parts.

4. CHECK TCM INSPECTION
1. Perform "DIAGNOSTIC PROCEDURE"
OK or NG
OK >> INSPECTION END.
NG >>
^ Perform TCM input/output signal inspection.
^ If NG. recheck TCM Pin terminals for damage or loose connections with harness connector.

COMPONENT INSPECTION
Overdrive Control Switch








^ Check continuity between terminals 1 and 2.

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.