P1776
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, A/T 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 KPH (40 MPH)
- During high-load operation
Conditions for lock-up operation:
- Under 68 to 76 KPH (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 KPH (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 engine ground.
ON BOARD DIAGNOSIS LOGIC
DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
CAUTION: Always drive vehicle at a safe speed.
NOTE: Always perform the test at a temperature of -10°C (14°F) or higher.
TESTING CONDITION: 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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 5 seconds.
3. Start engine.
4. Select "TCC S/V FNCTN P1776" of "A/T (TCC S/V)" in "DTC WORK SUPPORT" mode with CONSULT.
5. Touch "START".
6. When the following conditions are met, "TESTING" will be displayed on the CONSULT screen. Maintain the conditions continuously until "TESTING" changes to "COMPLETED". (It will take approximately 20 seconds.)
Selector lever: D (OD "ON")
Vehicle speed: 76 - 100 KPH (47 - 62 MPH)
CMPS.RPM (REF): Less than 3,200 rpm
B/FUEL SCHDL: 1.8 - 4.8 msec
THRTL P0S SEN: Less than 1.4V
If "TESTING" is not displayed after 5 minutes, retry from step 2.
7. Make sure that "OK" is displayed after touching "SELF-DIAG RESULTS".
If "NG" is displayed, refer to "DIAGNOSTIC PROCEDURE".
OR
With Generic Scan Tools
1. Start engine and warm it up to normal operating temperature.
2. Select MODE 7 with GST.
3. Perform test drive in "D" position (OD "ON") at least 20 seconds continuously under the following conditions.
Engine speed: Less than 3,200 rpm
Vehicle speed: 76 - 100 KPH (47 - 62 MPH)
4. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".
OR
Without Scan Tools
1. Start engine and warm it up to normal operating temperature.
2. Perform test drive in "D" position (OD "ON") at least 20 seconds continuously under the following conditions.
Engine speed: Less than 3,200 rpm
Vehicle speed: 76 - 100 KPH (47 - 62 MPH)
3. Stop the vehicle, turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
4. Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
5. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".
DIAGNOSTIC PROCEDURE
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".
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.
Torque converter clutch control valve
1. Disassemble torque converter clutch control valve assembly. Refer to "REPAIR FOR COMPONENT PARTS".
2. Check torque converter clutch control valve.
- Valve, and sleeve slide along valve bore under their own weight.
- Valve, and sleeve are free from burrs, dents and scratches.
- Control valve springs are free from damage, deformation and fatigue.
- Hydraulic line is free from obstacles.
3. If NG, replace torque converter clutch control valve.