The transmission control module (TCM) controls the torque converter clutch (TCC) solenoid valve pulse width modulation (PWM). The solenoid directs the hydraulic fluid for TCC apply and release. When the TCC is released, the engine is coupled by fluid to the transmission and TCC slip speeds of -300 RPM to +1,500 RPM, during heavy acceleration, are normal.
If the TCM detects low torque converter slip when the TCC is commanded OFF, then DTC P0742 sets. DTC P0742 is a type B DTC.
This diagnostic procedure supports the following DTC:
DTC P0742 Torque Converter Clutch (TCC) System - Stuck On
• | No throttle system DTC P0120. |
• | No ISS DTCs P0716 or P0717. |
• | No OSS DTCs P0722 or P0723. |
• | No TCC performance DTC P0741. |
• | No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826. |
• | No engine torque signal circuit DTC P2637. |
• | No TCC solenoid electrical DTCs P2764 or P2763. |
• | The engine run time is greater than 5 seconds. |
• | The IMS range is D5. |
• | The transmission fluid temperature is 20-130°C (68-266°F). |
• | The engine torque is greater than 80 N·m (59 lb ft). |
• | The throttle position is 12-90 percent. |
• | The transmission is not in 1st gear and the gear ratio is 0.73:1 to 2.27:1. |
• | The vehicle speed is greater than 15 km/h (9 mph). |
The following conditions occur 3 times in 1 ignition cycle:
• | The TCM commands the TCC OFF. |
• | The TCC slip is between -20 to +20 RPM for greater than 3.5 seconds. |
• | 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 freezes transmission adaptive functions. |
• | At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
• | At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame. |
• | The TCM stores DTC P0742 in TCM history. |
• | The ECM turns off the MIL after the sixth consecutive drive trip in which the TCM does not send a MIL illumination request. |
• | A scan tool can clear the DTC. |
• | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring. |
• | The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM. |
• | Rapid fluctuation in line pressure may set DTC P0742. Refer to Line Pressure Check . |
• | The customer may notice an engine stalling condition. |
The numbers below refer to the step numbers on the diagnostic table.
This step verifies that the PCM commanded the TCC PWM solenoid valve OFF and the slip speed is -20 to +150 RPM.
This step inspects and repairs the components that caused the DTC to set.
Step | Action | Value(s) | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||||||
Important:
While the TCC duty cycle is 0 percent, does the scan tool display a TCC slip speed within the specified range? | -20 to +20 RPM | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections | |||||||||||||
Did you find and correct a condition? | -- | Go to Step 4 | -- | |||||||||||||
4 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 5 | Go to Step 2 | ||||||||||||
5 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
The transmission control module (TCM) controls the torque converter clutch (TCC) solenoid valve pulse width modulation (PWM). The solenoid directs the hydraulic fluid for TCC apply and release. When the TCC is released, the engine is coupled by fluid to the transmission and TCC slip speeds of -300 RPM to +1,500 RPM, during heavy acceleration, are normal.
If the TCM detects low torque converter slip when the TCC is commanded OFF, then DTC P0742 sets. DTC P0742 is a type B DTC.
This diagnostic procedure supports the following DTC:
DTC P0742 Torque Converter Clutch (TCC) System - Stuck On
• | No throttle system DTC P0120. |
• | No ISS DTCs P0716 or P0717. |
• | No OSS DTCs P0722 or P0723. |
• | No TCC performance DTC P0741. |
• | No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826. |
• | No engine torque signal circuit DTC P2637. |
• | No TCC solenoid electrical DTCs P2764 or P2763. |
• | The engine run time is greater than 5 seconds. |
• | The IMS range is D5. |
• | The transmission fluid temperature is 20-130°C (68-266°F). |
• | The engine torque is greater than 80 N·m (59 lb ft). |
• | The throttle position is 12-90 percent. |
• | The transmission is not in 1st gear and the gear ratio is 0.73:1 to 2.27:1. |
• | The vehicle speed is greater than 15 km/h (9 mph). |
The following conditions occur 3 times in 1 ignition cycle:
• | The TCM commands the TCC OFF. |
• | The TCC slip is between -20 to +20 RPM for greater than 3.5 seconds. |
• | 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 freezes transmission adaptive functions. |
• | At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
• | At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame. |
• | The TCM stores DTC P0742 in TCM history. |
• | The ECM turns off the MIL after the sixth consecutive drive trip in which the TCM does not send a MIL illumination request. |
• | A scan tool can clear the DTC. |
• | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring. |
• | The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM. |
• | Rapid fluctuation in line pressure may set DTC P0742. Refer to Line Pressure Check . |
• | The customer may notice an engine stalling condition. |
The numbers below refer to the step numbers on the diagnostic table.
This step verifies that the PCM commanded the TCC PWM solenoid valve OFF and the slip speed is -20 to +150 RPM.
This step inspects and repairs the components that caused the DTC to set.
Step | Action | Value(s) | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||||||
Important:
While the TCC duty cycle is 0 percent, does the scan tool display a TCC slip speed within the specified range? | -20 to +20 RPM | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections | |||||||||||||
Did you find and correct a condition? | -- | Go to Step 4 | -- | |||||||||||||
4 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 5 | Go to Step 2 | ||||||||||||
5 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |