Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 24 other vehicles, including the 1992 GMC Yukon, 1992 GMC Vandura Special, 1992 GMC Vandura, 1992 GMC Value Van, and 1992 GMC Suburban. However, it is still accessible from the selected car via links, so may be relevant.

Clear codes and re-check for Code 39. If code resets, problem could be internal to the transmission. Code 39 will only set in 3rd gear. TCC slip in 4th gear will set Code 68.

Fig 1: CODE 39, Schematic, Torque Converter Clutch Stuck "OFF"

Courtesy of GENERAL MOTORS CORP.

Fig 2: CODE 39, Flow Chart, Torque Converter Clutch Stuck "OFF"

Courtesy of GENERAL MOTORS CORP.