DTC 0904

SYSTEM DESCRIPTION
The ECM controls torque converter clutch solenoid valve to cancel the lock-up condition of A/T When the solenoid valve is turned on, lock-up is cancelled. When the solenoid valve is turned off, Air lock-up is operational.

Conditions for lock-up cancel:
Torque converter clutch solenoid valve is turned "ON" when;
- Throttle valve is fully closed (during idling or deceleration)
- Engine coolant temperature is below 60°C (140°F)
- Vehicle speed is less than 64 km/h (40 MPH)
- During high-load operation
Conditions for lock-up operation:
- Under 68 to 76 km/h (42 to 47 MPH) (2/8 throttle on flat road), lock-up does not operate even when the torque converter clutch solenoid valve is "OFF".
- Over 106 to 114 km/h (66 to 71 MPH) (2/8 throttle on flat road), lock-up should operate because the torque converter clutch solenoid valve is "OFF".
To confirm vehicle lock-up, the torque converter clutch solenoid valve must be in operation ("ON" during idle and deceleration and "OFF" during acceleration) and engine speed should drop.
When the accelerator pedal is depressed (less than 2/8) in lock-up, the engine speed should not change abruptly. If there is a big jump in engine speed, there will be no lock-up.




CONSULT REFERENCE VALUE IN DATA MONITOR MODE




ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values and are measured between each terminal and (43) (ECCS ground).




ON BOARD DIAGNOSIS LOGIC

DIAGNOSTIC TROUBLE CODE 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.

With CONSULT
(1) Turn ignition switch "ON".
(2) Select "DATA MONITOR" mode with CONSULT.
(3) Wait at least 5 seconds.

OR

With Generic Scan Tool
(1) Turn ignition switch "ON" and wait at least 5 seconds.
(2) Select "MODE 7" with GST.

OR

Without Scan Tools
(1) Turn ignition switch "ON" and wait at least 5 seconds.
(2) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
(3) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.




DIAGNOSTIC PROCEDURE




WIRING DIAGRAM







COMPONENT INSPECTION
Torque converter clutch solenoid valve
1. Check resistance between torque converter clutch solenoid valve terminals (1) and (3).

Resistance: Approximately 25 Ohms [at 25°C (77°F)]

2. Remove torque converter clutch solenoid valve. Refer to "ON-VEHICLE SERVICE" in AT section.
3. Supply the solenoid valve terminals (1) and (3) with battery voltage and check the solenoid valve operation.
Torque converter clutch solenoid valve should be operated.
4. If NG, replace torque converter clutch solenoid valve.