DTC P0742 TCC System Stuck On. Buick Skylark 1997

For 1990-2009 cars only

Makes 🢒 Buick 🢒 1997 🢒 Skylark 🢒 DTC 🢒 DTC P0742 TCC System Stuck On

DTC P0742 TCC System Stuck On 3.1L VIN M

OBD II Symbol Description Notice
Automatic Transmission Controls Schematics 3.1L VIN M
Automatic Transmission Components 3.1L VIN M

Circuit Description

The Torque Converter Clutch Solenoid Valve (TCC Sol Valve) acts on the hydraulic fluid, controlling TCC apply and release.

If the PCM detects 3 occurrences of TCC slip between -20 and +30 RPM when the TCC is commanded OFF, then DTC P0742 sets. DTC P0742 is a type B DTC.

Conditions for Setting the DTC

•	No TP DTCs P0122 or P0123

•	No VSS DTCs P0502 or P0503

•	No TCC PWM Solenoid Electrical DTC P1860

•	No TCC Enable Solenoid Electrical DTC P0740

•	Not in fuel shut off

•	The engine speed is more than 500 RPM for 5 seconds.

•	The PCM has commanded the TCC OFF.

•	The commanded gear is not 1st.

•	The transmission gear indicates 2nd, 3rd or 4th.

•	The throttle angle is14-50%.

•	The engine torque is 109-271 N·m (70-200 ft lbs.).

•	No gear change within 3 seconds.

•	The vehicle speed is 32-113 km/h (20-70 mph).

•	The engine speed is 800-4000 RPM.

•	The TCC slip speed is -20 to +25 RPM, 3 occurrences for 5 seconds.

Action Taken When the DTC Sets

The PCM illuminates the Malfunction Indicator Lamp (MIL) after two consecutive trips with a failure reported.

Conditions for Clearing the DTC

•	The PCM turns OFF the MIL after three consecutive ignition cycles without a failure reported.

•	A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

Diagnostic Aids

•	Check for PRNDL DTC P0705. DTC P0705 affects transmission operation. This may set DTC P0742 falsely.

•	Inspect the transmission fluid for debris.

Test Description

The step number below refers to the step numbers on the diagnostic table.

A TCC slip speed of -20 to +30 RPM indicates that this DTC is not current. Refer to the Diagnostic Aids. Inspect for PRNDL DTC P0705.

DTC P0742 Torque Converter Clutch System Stuck ON

Step

Action

Value(s)

Yes

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Install the scan tool.
With the engine OFF, turn the ignition switch to the RUN position.

Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function erases the stored Freeze Frame and Failure Records from the PCM.

Record the DTC Freeze Frame and Failure Records.
Select TCC Slip Speed.

Was the TCC slip speed within the range specified?

-20 RPM to +50 RPM

Go to Diagnostic Aids

Go to Step 3

Inspect for the following conditions:

•	The TCC enable solenoid stuck ON because of sediment.

•	The TCC apply valve stuck ON because of sediment.

•	Refer to Control Valve Body Assembly Inspection, Section 7.

Did you find and correct a problem?

Go to Step 4

In order to verify your repair, perform the following procedure:

Select DTC.
Select Clear Info.
Operate the vehicle under the following conditions:

•	The gear range is D2, D3, or D4.

•	The commanded gear is not 1st.

•	The engine speed is greater than 500 RPM for 5 seconds.

•	Not in fuel shut off

•	The engine torque is 109-271N·m (70-200 ft lbs.).

•	The throttle position is greater than 14-50%.

•	The PCM commands the TCC OFF.

•	The TCC slip speed is 150-2000 RPM for 5 seconds.

•	No gear change within 3 seconds

•	The vehicle speed is 32-113 km/h (20-70 mph).

•	The engine speed is 800-4000 RPM.

Select Specific DTC. Enter DTC P0742.

Has the test run and passed?

System OK

Begin diagnosis again, Go to Step 1

DTC P0742 TCC System Stuck On 2.4L VIN T