INTERMITTENT WIRING HARNESS SHORT (REPL. INTERNAL HARNESS)

SUBJECT: INTERMITTENT WIRING HARNESS SHORT TO GROUND

MODELS: 1993 C/K, S/T TRUCKS, AND M/L AND G VANS w/4L60-E TRANSMISSION (M30)

CONDITION

Some 1993 vehicles equipped with the 4L60-E transmission may blow an ignition fuse which forces the transmission to default into 3rd gear starts when in D4. Possible diagnostic trouble codes (DTC's) 66, 67, 81, and 82 may exist.

CAUSE (Figure 1)

The 4L60-E transmissions built before October 1, 1992 (Julian Date 275), may have a wiring harness that has a wire connector that may short to the valve body.

CORRECTION

Follow the diagnostic procedure using Figures 2, 3, and 4.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.