P0740

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Description





The torque converter clutch solenoid valve is activated, with the gear in "D1", by the TCM in response to signals sent from the vehicle speed and throttle position sensors. Lock-up piston operation will then be controlled.

Lock-up operation, however, is prohibited when A/T fluid temperature is too low.

When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.





CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE





TCM TERMINALS AND REFERENCE VALUE





ON BOARD DIAGNOSIS LOGIC

DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION PROCEDURE

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch OFF and wait at least 5 seconds before conducting the next test.

After the repair, perform the following procedure to confirm the malfunction is eliminated.

With CONSULT-II
1. Turn ignition switch ON.








2. Select "DATA MONITOR" mode for "ENGINE" with CONSULT-II and wait at least 1 second.

With GST
- Follow the procedure "With CONSULT-II".

AT-TCV-01:

Wiring Diagram-AT-TCV

Diagnostic Procedure
1. CHECK GROUND CIRCUIT
1. Turn ignition switch to OFF position.
2. Disconnect terminal cord assembly connector in engine compartment.
3. Check resistance between terminal cord assembly connector E72 terminal 5 and ground. Refer to wiring diagram.
Is resistance approximately 10 - 20 ohms?
Yes >> GO TO 2
No >>.
1. Remove oil pan.
2. Check the following items:
- Torque converter clutch solenoid valve.
- Harness of terminal cord assembly for short or open

2. CHECK RESISTANCE
1. Turn ignition switch to OFF position.
2. Disconnect TCM harness connector.
3. Check resistance between terminal cord assembly connector E72 terminal 5 and TCM harness connector M77 terminal.
3. Refer to wiring diagram.
If OK, check harness for short to ground and short to power.
Is resistance approximately 0 ohms?
Yes >> GO TO 3
No >> Repair open circuit or short to ground or short to power in harness or connectors.

3. CHECK DTC
Perform "DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION PROCEDURE".
OK or NG
OK >> INSPECTION END
NG >>
1. Perform TCM input/output signal inspection.
2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.

Component Inspection
TORQUE CONVERTER CLUTCH SOLENOID VALVE
- For removal, refer to "Control Valve Assembly and Accumulators".

Resistance Check








- Check resistance between terminal 7 and ground.

Operation Check





- Check solenoid valve by listening for its operating sound while applying battery voltage to the terminal 7 and ground.