Torque Converter Clutch, Checking

Torque Converter Clutch, Checking

• Check DTC memory of Transmission Control Module (TCM) (J217) before troubleshooting.

• Check also DTC memory of Engine Control Module (ECM), as DTC's of the ECM can lead to transmission malfunctions.

• Check ATF level before troubleshooting. Refer to => [ ATF Level, Checking ] .

Torque converter clutch can only be checked when driving in On Board Diagnostics (OBD).





CAUTION!
• Test and measuring equipment must always be secured to the rear seat and operated from there by a second person.

• If test and measuring equipment is operated from the passenger seat, the person seated there could be injured in the event of an accident involving deployment of the passenger-side airbag.

- With ignition switched off, connect Vehicle Diagnosis, Testing and Information System (VAS 5051) to Data Link Connector (DLC).

- Start engine.

Display on (VAS 5051):





- Tap Vehicle Self-Diagnosis button.

Display on (VAS 5051):





- In selection - 1 -, click on function "02 - Transmission electronics".

- Wait until the next indication appears on display.

Display on (VAS 5051):





- From list - 1 - select function "08 - Reading measured value block".

Display on (VAS 5051):





1 Enter display group, max. input value = 255

- In button field - 2 -, tap 7 button for "display group 007" and confirm entry by tapping Q button.

- Perform a road test.

Display on (VAS 5051):





- Check indication in display fields - 3 - and - 4 -. Specified values:

3 TC closed
4 0 to 20/min

If indications do not resemble description, ratio of transmission RPM to engine speed with closed torque converter clutch does not match (implausibility).

• Causes:

- Torque converter clutch circuit malfunctioning, worn.

- Incorrect torque converter.

- Automatic Transmission Pressure Regulating Valve 4 (N218) mechanically malfunctioning.

- Problems in ATF lines to Automatic Transmission Pressure Regulating Valve 4 (N218).

- Valve for torque converter pressure malfunctioning.

- Torque converter clutch valve faulty.

- Press <- button to end function "08 - Read measured value block".

- Select "06 - End output" function.

- Switch off ignition and disconnect diagnostic connector.