DTC Advanced Diagnostics: P0741
DTC P0741:Torque Converter Clutch Circuit Performance or Stuck OFF (Engine Type: J35Y1)

General Description

Torque converter clutch operation
A/T clutch pressure control solenoid valve D
ON (100 %)
OFF (0 %)
Shift solenoid valve C
ON (12 V)
Torque converter clutch:
maximum duty
Torque converter clutch:
minimum duty
OFF (0 V)
Torque converter clutch OFF
Torque converter clutch OFF

The power transfer capacity of the torque converter clutch is controlled by the balance of automatic transmission fluid (ATF) supplied to and discharged from the torque converter clutch and the torque converter. When hydraulic pressure supplied to the torque converter clutch is less than the torque converter internal pressure, lock up is off. When hydraulic pressure supplied to the torque converter clutch is greater than the torque converter internal pressure, lock up is on. As the hydraulic pressure supplied to the torque converter clutch is increased, the power transfer capacity of the torque converter clutch is increased. The supply of hydraulic pressure is switched by shift solenoid valve C and the lock-up shift valve. When the powertrain control module (PCM) turns on shift solenoid valve C, the hydraulic pressure is supplied to the torque converter clutch. When the PCM turns off shift solenoid valve C, the hydraulic pressure is not supplied to the torque converter clutch. The balance of hydraulic pressure supplied to the torque converter clutch and the torque converter is controlled by A/T clutch pressure control solenoid valve D and the lock-up control valve. When the PCM turns on A/T clutch pressure control solenoid valve D, the power transfer capacity of the torque converter clutch is at its maximum. When the PCM turns off A/T clutch pressure control solenoid valve D, the power transfer capacity of the torque converter clutch is at its minimum. If the ratio of engine speed and input shaft (mainshaft) speed is not about 1:1 while the PCM is issuing the command to turn shift solenoid valve C and A/T clutch pressure control solenoid valve D on, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status
Execution
Once per driving cycle
Sequence
None
Duration
22 seconds or more
DTC Type
Two drive cycles, MIL off, A/T gear position indicator blinks
OBD Status
PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions
Condition
Minimum
Maximum
Engine coolant temperature [Engine Coolant Temperature]
158 °F (70 °C)
221 °F (105 °C)
Battery voltage
[BATTERY VOLTAGE]
11 V
–
Shift status
6th gear
Torque converter clutch
During controlling operation
No active DTCs set (prevents monitor from running)
P0117, P0118, P0122, P0123, P0222, P0223, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0351, P0352, P0353, P0354, P0355, P0356, P0705, P0706, P0716, P0717, P0718, P0721, P0722, P0723, P0746, P0747, P0751, P0752, P0756, P0757, P0761, P0762, P0776, P0777, P0796, P0797, P0962, P0963, P0966, P0967, P0970, P0971, P0973, P0974, P0976, P0977, P0979, P0980, P1658, P1659, P1683, P1684, P2101, P2118, P2122, P2123, P2127, P2128, P2135, P2138, P2176, P2648, P2649, P2653, P2654, P2658, P2659, P2714, P2720, P2721
Other
When both the vehicle speed and the accelerator pedal position are in Enable Range

[ ]: HDS Parameter

Malfunction Threshold
The ratio of the engine revolution to the transmission input pulse does not reach about 100 % for at least 22 seconds.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
Torque converter clutch failure
A/T clutch pressure control solenoid valve D failure
Shift solenoid valve C failure
Lock-up shift valve stuck
Lock-up control valve stuck

Confirmation Procedure
Operating Condition
1.
Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
2.
Drive the vehicle at a constant speed of 60 mph (96 km/h) for at least 22 seconds.
Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
None.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the A/T gear position indicator blinks and a Confirmed DTC and the freeze data are stored. The MIL does not come on.

Conditions for clearing the DTC
The A/T gear position indicator comes off by pressing the engine start/stop button to select the OFF mode. The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.