PROD. INFO. - POSS. INTERMIT. SECOND GEAR START IN D2 (COLD)

SUBJECT: POSSIBLE INTERMITTENT SECOND GEAR START IN D2 WHEN COLD (PRODUCT INFORMATION)

VEHICLES AFFECTED: 1990-93 "A,J,L,N,W,T" MODELS AND "U" VAN WITH 3T40 AUTOMATIC TRANSAXLE (RPOMD9)

CONDITION:

Some 1990-93 vehicles with HYDRA-MATIC 3T40 transaxles (RPO MD9) may intermittently start out in second gear when the gear selector is in the intermediate (D2) range, and ambient temperature is low.

CAUSE:

A pressure calibration change was made during the 1990 Model Year to enhance transaxle performance during heavy throttle operation in the intermediate (D2) range. At low ambient temperatures, transaxle fluid viscosity increases and may not exhaust quickly enough from the governor circuit to return the 1-2 shift valve to the downshifted position. This results in a second gear start.

CORRECTION:

No correction is necessary or available for this condition. As the transaxle warms up, fluid viscosity decreases and no longer affects the normal operation of the 1-2 shift valve. This condition does not create any durability concerns.

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.