2006 Corvette: Service Bulletin: 6L80 Automatic Transmission Delayed Engagement From PARK to DRIVE or PARK to REVERSE (Reprogram Transmission Control Module (TCM))

Service Bulletin #: 06-07-30-002

Date: January 20, 2006

Subject: 6L80 Automatic Transmission Delayed Engagement From PARK to DRIVE or
PARK to REVERSE (Reprogram Transmission Control Module (TCM))

Model(s): 2006 Chevrolet Corvette with Transmission – Auto 6 Spd, HMD, 6L80 (RPO MYC)

Condition
Some customers may comment on a delayed engagement into Drive or Reverse when shifting from Park.

Tip: Normal Park/Neutral to Reverse or Drive engagement time will be in the vicinity of one and a half (1.5 seconds) if the automatic transmission fluid (ATF) is above 0°C (32°F) . When the ATF is colder than 0°C (32°F), the engagement time will become longer with the colder the transmission fluid.

Correction
A revised transmission calibration has been released to address this issue. Follow the service procedure below.

1. Reprogram the TCM with an updated software calibration released with TIS satellite data update version #1 on 01/09/06 or later. Refer to Transmission Control Module Programming and Setup in Vehicle Control Systems (SI Document ID #1466621).

Important: After reprogramming the TCM, Service Fast Learn Adapts must be performed.

2. Perform the Service Fast Learn Adapts. Refer to Service Fast Learn Adapts (SI Document ID #1688788).

Important: After performing Service Fast Learn Adapts, the Garage Shift Adapts must also learned by following the procedure below.

3. With a scan tool, ensure that the transmission temperature is 30°C (86°F) or higher.

4. With the engine at idle, shift from Reverse to Drive leaving the shift lever in Drive for five seconds. After five seconds, shift back to the Reverse position leaving the shift lever in Reverse for five seconds. Perform this procedure 20 times (R-D-R-D-R-D...). The transitions need to be directly to Drive and Reverse, without stopping in Neutral.

5. With the engine at idle, shift from Neutral to Drive leaving the shift lever in Drive for five seconds. After five seconds, shift back to the Neutral position leaving the shift lever in Neutral for five seconds. Perform this procedure 10 times (N-D-N-D-N-D...).

6. With the engine at idle, shift from Neutral to Reverse leaving the shift lever in Reverse for five seconds. After five seconds, shift back to the Neutral position leaving the shift lever in Neutral for five seconds. Perform this procedure 10 times (N-R-N-R-N-R...).

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.