TCM Self-Diagnosis Does Not Activate {Park/Neutral Position (PNP), Overdrive Control and Throttle Position Sensor [Accelera
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.
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
^ Harness for short or open between PNP switch and TCM
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. Refer to Overdrive Control Switch.
^ Harness for short or open between TCM and overdrive control switch
^ Harness of ground for overdrive control switch 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 AT-187, DTC P1705 THROTTLE POSITION SENSOR [ACCELERATOR PEDAL POSITION (APP) SENSOR]. P1705
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4. CHECK TCM INSPECTION
1. Perform AT-250, DIAGNOSTIC PROCEDURE
OK or NG
OK >> INSPECTION END.
NG >>
^ Perform TCM input/output signal inspection. Pinout Values and Diagnostic Parameters
^ 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. Refer to Control Cable Adjustment.
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 Park/Neutral Position (PNP) Switch Adjustment.
6. If NG on step 4, replace PNP switch.