The PCM TCM controls the locking and unlocking of the Torque Converter Clutch ( or Damper Clutch ), to the input shaft of the transmission, by appling hydraulic pressure. The main purpose of T/C clutch control is to save fuel by decreasing the hydraulic load.
The TCM increases the duty ratio to engage the Damper Clutch by monitoring the slip rpms (difference vlaue beteween engine speed and turbine speed ). If a very small amount of slip rpm is maintained though the TCM applies 0% duty ratio value, then the TCM
Item | Detecting Condition & Fail Safe | Possible cause |
DTC Strategy | ● Stuck "ON" | ※ TORQUE CONVERTER(DAMPER) CLUTCH : TCC ● Faulty TCC or oil pressure system ● Faulty TCC solenoid valve ● Faulty bady control valve ● Faulty TCM(PCM) |
Enable Conditions | ● Throttle position ＞1.5V ● Output speed ＞1000rpm ● Solenoid status OFF ● A/T range switch D,SP ●Time after TCC release ＞5secs | |
Threshold value | ●(rationality-low) Calculated slip (engine speed-input speed)＜5rpm or (rationality-high) Calculated slip ＞-5rpm | |
Diagnostic Time | ● more than 5secs | |
Fail Safe | ● Damper clutch abnormal system (If diagnosis code P0741 is output four times, TORQUE CONVERTER(DEMPER) CLUTCH is not controlled by PCM/TCM) |
Connect scantool to data link connector(DLC)
Engine "ON".
Sellect "D RANGE" and drive vehicle
Monitor the "TORQUE CONVERTER(DAMPER) CLUTCH" parameter on the scantool
Specification : TCC SLIP>5RPM
Are "TCC SOLENOID DUTY and TCC SLIP" within specifications ?
▶ Fault is intermittent caused by poor contact in the sensor's and/or TCM(PCM)'s connector or was repaired and TCM(PCM) memory was not cleared. Throughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration or
▶ Go to "Component Inspection" procedure
CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE
Connect scantool to data link connector(DLC)
Ignition "ON" & Engine "OFF".
Select A/T Solenoide valve Actuator test and Operate Actuator test.
Can you hear operating tone for using TCC SOLENOID VALVE Actuator Testing Function ?
▶ Go to "CHECK OIL PRESSURE" as below.
▶ Replace "TCC SOLENOID VALVE" as necessary and Go to "Verification Vehicle Repair" procedure
CHECK OIL PRESSURE
Connect Oil pressure guage to "DR" port.
Ignition "ON" & Engine "OFF".
After connecting Scantool and monitor the "TCC SOLENIOD VALVE DUTY" parameter on the Scantool data list.
Select 1st gear and accelerate Engine speed to 2500 rpm
Measure oil pressure
Specification : approx. 6.1kg/cm²
Is oil pressure value within specification?
▶ Repair TORQUE CONVERTER CLUTCH(REPLACE Torque Converter ) as necessary and Go to "Verification Vehicle Repair " procedure.
▶ Replace A/T ass'y (possible to BODY CONTROL VALVE faulty) as necessary and Go to "Verification Vehicle Repair " procedure.
Refer to DTC P0741
