DTC 39

Torque Converter Clutch Diagnostic Chart:

Torque Converter Clutch Circuit:

Circuit Description:
The purpose of the Torque Converter Clutch (TCC) is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise condition. This allows the convenience of the automatic transmission and the fuel economy of a manual transmission.

Switched battery voltage is supplied to the TCC solenoid which is located on the valve body. When the PCM/TCM closes the TCC driver, the solenoid will activate a valve within the valve body. Pressure will then be applied to the torque converter clutch. The PCM/TCM will continue to open and close the TCC driver very rapidly to modulate pressure.

Code 39 will set if:
^ TCC is engaged.
^ TCC "slip" is greater than 65 rpm for 2 seconds.
^ 2nd or 3rd gear is selected or indicated.

Test Description:
Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test will determine if transmission is receiving a TCC command to the pass-thru connector.

2. Checks for power to transmission.

3. Determines if PCM/TCM is commanding TCC "ON."


Diagnostic Aids:
Clear codes and recheck for Code 39. If code resets, problem could be internal to the transmission. Testing and Inspection

Code 39 will only set in 3rd gear. TCC slip in 4th gear will set Code 68.