06-06-04-042B: LM4, LM7, L59, LR4, LQ9, LQ4, LY6 Throttle Actuator Control (TAC) Module Codes, MIL/SES DTCs P2108, P1516, U0107, Reduced Engine Power (Reprogram PCM) - (Mar 25, 2009)
|Subject:||LM4, LM7, L59, LR4, LQ9, LQ4, LY6 Throttle Actuator Control (TAC) Module Codes, MIL/SES DTCs P2108, P1516, U0107, Reduced Engine Power (Reprogram PCM)|
|Models:||2006 Cadillac Escalade Models|
|2006 Chevrolet Avalanche, Express 1500/2500/3500, Silverado, Silverado Flex Fuel, Silverado Hybrid, Silverado SS, Silverado 2500/3500 HD, Suburban, Tahoe|
|2006-2007 Chevrolet W3500/W4500 Series Medium Duty Tilt Cab|
|2006 GMC Savana 1500/2500/3500, Sierra, Sierra Flex Fuel, Sierra Hybrid, Sierra Performance Edition, Sierra 2500/3500 HD, Yukon Models|
|2006-2007 GMC W3500/4500 Series Medium Duty Tilt Cab|
|All Equipped with GEN III or GEN IV Vortec 4.8L, 5.3L or 6.0L V8 Engine (VINs V, T, Z, N, U -- RPOs LR4, LM7, LM4, L59, LQ9, LQ4, LY6)|
This bulletin is being revised to delete the 2007 model year and engines except for the 2007 MD 3500/4500 Tilt Cab Models. Please discard Corporate Bulletin Number 06-06-04-042A (Section 06 -- Engine/Propulsion System).
Some customers may experience engine operation in the Reduced Engine Power mode, an MIL/SES light on and DTCs P2108, P1516, and U0107 set.
This condition may be caused by an error in the TAC Module communication software.
| • ||Using the scan tool, check the Freeze Frame/Failure record for Engine Run Time and Vehicle Speed at the time the DTC occurred. If the above concern is encountered at start up and the vehicle speed is at zero, Do Not replace the TAC module for this condition. Refer to this bulletin for reprogramming the PCM.|
| • ||If the Freeze Frame/Failure record indicates that the DTC occurred while driving, the condition may have been caused by static electricity resulting from improperly grounded equipment. If the vehicle has been upfitted with a ladder rack, utility bed or similar equipment, install a ground strap between the frame and the upfitted equipment, then evaluate repairs. If pulling a trailer, proper trailer grounds must be installed according to the instructions in the Owners Manual. |
| • ||If the DTCs occur while the vehicle is in motion (speed greater than zero) and there is no apparent source of static electricity, proceed with diagnosis according to DTC P2108 service procedure in SI.|
PCM Reprogramming Instruction (if indicated from Diagnostic Aids)
Reprogram the PCM with the latest calibrations if the above concern is encountered. An updated PCM calibration is now available to address this concern. This calibration, or any that follow, is designed to address this concern. Refer to Service Programming System (SPS) using the appropriate Service Information (SI) procedures. The new PCM calibrations will be available to dealerships as part of TIS2000 incremental satellite update version 8.5, which was broadcast to dealers on 08/20/2006. For the dealerships that use CDs, the CD version will be 8.5 for 2006, which will be mailed 08/24/2006. As always, make sure your Tech 2® is updated with the latest software version.