VT25-E Automatic Transmission

VT25-E AUTOMATIC TRANSMISSION

DTC P0741





Circuit Description with VT25-E Automatic Transmission
The transmission control module (TCM) controls the TCC pressure control solenoid valve pulse width modulation. When the solenoid is commanded on, it exhausts release oil and allows regulated apply oil to flow to the apply circuit of the TCC system. The pressure in this system applies the pressure plate to the converter housing, and couples the transmission and engine directly through the TCC. The TCC slip speed should be near zero when fully applied.

When the TCM detects high torque converter slip when the TCC is commanded on, DTC P0741 sets. DTC P0741 is a type B DTC.

Conditions for Running the DTC
^ No engine torque DTC P1779.
^ No OSS DTCs P0722 or P0723.
^ No ISS DTCs P0716 or P0717.
^ No TCC system stuck ON DTC P0742.
^ No transmission range switch DTCs P0705, P1756, or P1758.
^ No TCC enable solenoid valve DTCs P1888 or P1889.
^ The ignition voltage is 8 - 18 volts.
^ The engine speed is greater than 500 RPM for 5 seconds.
^ The engine torque and throttle angle signals are valid.
^ The selected range is DRIVE, INTERMEDIATE, or LOW.
^ The time since the gear select lever change is greater than 6 seconds.
^ The transmission fluid temperature is 21 - 130°C (70 - 266°F).
^ The engine torque is 30 - 300 Nm (22 - 221 ft. lbs.).
^ The throttle position angle is greater than 5 percent.
^ The speed ratio is greater than 0.38.
^ The commanded TCC pressure is greater than 100 kPa (15 psi) for 5 seconds.
^ The TCC is commanded ON.

Conditions for Setting the DTC
The TCM commands the TCC ON, and the TCC slip speed is greater than 220 RPM for 3 seconds 3 times within the same ignition cycle.

Action Taken When the DTC Sets
^ The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
^ The TCM inhibits TCC engagement.
^ The TCM limits the commanded speed ratio to 1.6 or less.
^ The TCM freezes torque converter clutch (TCC) transmission adaptive functions.
^ The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
^ The TCM stores DTC P0741 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
^ The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
^ A scan tool can clear the MIL/DTC.
^ The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
^ The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Diagnostic Aids
^ Inspect the transmission fluid lines to the radiator. The lines may be pinched, plugged or twisted.
^ A worn or cut input shaft O-ring seal can cause DTC P0741 to set.
^ Inspect for sediment contamination caused by debonding of the TCC friction plate.

Test Description
The number below refers to the step number on the diagnostic table.
2. This step inspects the transmission fluid to ensure that it is at the proper level.