DTC 39, Torque Converter Clutch Stuck Off (1994): Notes

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

PCM/TCM commands the TCC PWM solenoid on by modulating TCC signal fluid acting on converter clutch shift valve. TCC fluid applies torque converter clutch.

DTC 39 will set when DTC(s) 28, 71 or 74 is not present, TCC is commanded on, TCC slip speed is greater than 65 RPM, transmission range switch indicates "D3" or "D4", transmission is in 2nd or 3rd gear and all conditions are met for 2 seconds. PCM/TCM will inhibit 4th gear if in hot mode.

NOTE: Test number refers to number on diagnostic chart.

Test Number 1) This test checks the mechanical and hydraulic operation of TCC, while commanded on by PCM/TCM.