P0740

Description





The torque converter clutch solenoid valve is activated, with the gear in D4, 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 TCC SOLENOID/CIRC with CONSULT-II or P0740 without CONSULT-II is detected when TCM detects an improper voltage drop when it tries to operate the solenoid valve.

POSSIBLE CAUSE
Check the following items.
- Torque converter clutch solenoid valve
- Harness or connectors
(The solenoid circuit is open or shorted.)

DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION PROCEDURE

NOTE: If "DTC 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".





WIRING DIAGRAM - AT - TCV

Diagnostic Procedure





1: CHECK VALVE RESISTANCE





2: CHECK VALVE OPERATION





3: CHECK POWER SOURCE CIRCUIT





4: CHECK DTC





5: CHECK TCM INSPECTION