Some customers may comment that occasionally the seat heater will not operate when activated. If the ignition key is cycled OFF and back ON again, the heated seat will operate correctly. Also, on some LB7 diesel engine vehicles, the seat heater may turn itself off during the first 10 minutes of operation. This occurs only with the first activation for the day and works correctly with subsequent activations immediately after the event. These conditions are intermittent and DTC B3941 may be set.
Technicians are to reprogram the driver seat module with an updated software calibration. This new service calibration was released with TIS satellite data update version 6.5 available June 13, 2005. As always, make sure your Tech 2® is updated with the latest software version.
Driver Seat Module - Reprogram
*This is a unique labor operation number for use only with this bulletin. This number will not be published in the Labor Time Guide.
When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
A customer may comment that the front passenger or drivers heated seats turn on by themselves. Dealer technicians my not be able to duplicate the concern and no DTCs will be set. This concern maybe caused by the customer inadvertently contacting the heated seat switch.
To correct this concern, a new low profile switch has been released. The new part number switches are as follows:
15116862 drivers w/ memory, heated, and adjusted pedals
15116863 drivers w/ memory and heated only
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.
(03 and 04 Chevrolet Silverado) and (03 and 04 Chevrolet Avalanche) and (03 and 04 Chevrolet Tahoe, Suburban) and (03 and 04 GMC Sierra, Sierra Denali) and (03 and 04 GMC Yukon, Yukon XL, Denali, Denali XL) and (03 and 04 Cadillac Escalade, EXT, ESV)