INT NO TCC OR CEL CODE 62/26 (REPLACE 2ND GEAR SWITCH)

MODELS AFFECTED: 1988-89 CENTURY AND SKYLARK MODELS WITH 3T40/125C TRANSMISSIONS BULLETIN COVERS --------------- A condition, of inoperative or no TCC Torque Converter Clutch on a 1988 - 1989 THM 125C/HYDRA-MATIC 3T40 caused by a 2nd gear switch (338) that may be inoperative. Vehicle may exhibit intermittent service engine soon light and/or code 62 or 26 will be stored in the E.C.M.

DATE OF PRODUCTION CHANGE (Figure 1)

The 2nd gear switch has a 3-digit code stamped on top of the switch (metal side). The first 2 digits in the code represent the week in which the solenoid was built; the 3rd digit represents the year. All switches built with a number before Julian Date 179 (April 28, 1989), or 3rd digits of 7 or 8) when exposed to ambient operating temperatures may exhibit the following conditions:

1. Loose (flat blade terminals) 2. Terminals will appear blue or black in color

Inspect the torque converter clutch solenoid, third gear switch and entire wiring harness assembly for excessive heat exposure. 2nd gear switches produced after Julian Date 179 (April 28, 1989) are not affected.

SERVICE PROCEDURE

Do not attempt to repair suspect 2nd gear switches. If an inoperative 2nd gear switch is found in any THM 125C/HYDRA-MATIC 3T40, replace it with a new one.

SERVICE PARTS INFORMATION

Refer to the following part number when replacement of the solenoid assembly is necessary.

Part Number Description ----------- ----------- 8664388 Switch, 2nd Gear

Parts are currently available from GMSPO.

SERVICE MANUAL REFERENCE

Whenever servicing a 2nd gear switch on any THM 125C/HYDRA-MATIC 3T40, refer to the Unit Repair Section of your service manual.

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.