P0741
DTC P0741 TORQUE CONVERTER CLUTCH CIRCUIT - STUCK OFFGENERAL DESCRIPTION
The PCM controls the locking or unlocking of the Torque Converter Clutch (or Damper Clutch) by applying hydraulic pressure. The main purpose of the TCC control is to save fuel by decreasing the hydraulic load inside the torque converter. The PCM outputs duty pulses to control the torque converter clutch control solenoid valve and hydraulic pressure is applied to the torque converter according to the torque converter clutch duty ratio value. When the duty ratio is high, high pressure is applied and the torque converter clutch is locked. The normal operating range of the torque converter clutch control duty ratio value is from 30% (unlocked) to 85% (locked).
DTC DESCRIPTION
The PCM increases the duty ratio to engage the torque converter clutch, monitoring the slip rpms (difference between engine speed and turbine speed). To decrease the slip of the torque converter clutch, the PCM applies more hydraulic pressure by increasing the duty ratio. When the slip rpm does not drop down below the specification with 100% duty ratio, the PCM determines that the torque converter clutch is stuck OFF and sets this code.
DTC DETECTING CONDITION
DTC DETECTING CONDITION:
MONITOR SCAN TOOL DATA
1. Connect SCAN TOOL to data link connector (DLC).
2. Engine ON.
3. Select D RANGE and drive vehicle.
4. Monitor the TORQUE CONVERTER (DAMPER) CLUTCH parameter on the SCAN TOOL.
Specification: TCC, SLIP < 160 RPM (In condition that TCC SOL. DUTY > 80%
Specification:
5. Are TCC SOLENOID DUTY and TCC SLIP within specifications?
YES > Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration or damage. Repair or replace as necessary and go to Verification of Vehicle Repair procedure.
NO > Go to Component inspection procedure.
COMPONENT INSPECTION
1. CHECK TORQUE CONVERTER CLUTCH SOLENOID VALVE
1. Connect SCAN TOOL to data link connector (DLC).
2. Ignition ON & Engine OFF.
3. Select A/T solenoid valve actuator test and operate actuator test.
4. Can you hear operating tone for using TCC SOLENOID VALVE actuator testing function?
YES > Go to CHECK OIL PRESSURE.
NO > Replace TCC SOLENOID VALVE as necessary and go to Verification of Vehicle Repair procedure.
2. CHECK OIL PRESSURE
1. Connect oil pressure gauge to DA and DR ports.
2. Ignition ON & Engine OFF.
3. After connecting scan tool and monitor the TCC SOLENOID VALVE DUTY parameter on the SCAN TOOL data list.
4. Select the D range and accelerate engine speed to 2500 rpm.
5. Measure oil pressure.
Specification:
Specification:
6. Is oil pressure value within specification?
YES > Repair TORQUE CONVERTER CLUTCH (REPLACE Torque Converter) as necessary and go to Verification of Vehicle Repair procedure.
NO > Replace A/T assembly (or valve body assembly) as necessary and go Verification of Vehicle Repair procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect SCAN TOOL and select Diagnostic Trouble Codes (DTCs) mode.
2. Using a SCAN TOOL, Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present?
YES > Go to the applicable troubleshooting procedure.
NO > System performing to specification at this time.