2006 Corvette: Service Bulletin: Automatic Transmission, Busy Shifting, MIL Illuminated, DTC P1751

Service Bulletin #: 1741321

Date: December 9, 2005

Subject: Automatic Transmission, Busy Shifting, MIL Illuminated, DTC P1751

Model(s): 2006 Chevrolet Corvette, 2006 Cadillac XLR-V and STS-V, 2007 Cadillac Escalade, 2007 GMC Yukon

Equipped with 6L80 (RPO - MYC) Automatic Transmission

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern
Some customers may experience busy or frequent up and down shifts in 3rd, 4th, 5th or 6th gear at approximately 30-50 mph. The MIL may also be illuminated and a DTC P1751 stored in the TCM.

Recommendation/Instructions:
These conditions may be caused by an undersized hole or debris in the control valve body spacer plate.

To correct this condition the control valve body spacer plate must be replaced. These parts are not currently available from GMSPO and must be obtained by contacting Technical Assistance. If the control valve body spacer plate is required a complete valve body assembly including TCM will be sent to the dealer at no charge.

Service Procedure
Refer to SI document # 1670458 - Control Valve Lower and Upper Body Replacement for the proper procedure. The TCM must be programmed after installation of the control valve body assembly, refer to SI document # 1466621 - Transmission Control Module Programming and Setup. Service Fast Learn Adapts must also be run, refer to SI document # 1688788 for that procedure.

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.