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LR4, LY2, L33, LH6, LM7, L59, LC9, LMG, LY5, LS2, LQ9, LQ4, L76, LY6 Throttle Actuator Control (TAC) Module Codes, MIL/SES DTCs P2108 P1516, U0107, Reduced Engine Power (Reprogram PCM)

Subject: LR4, LY2, L33, LH6, LM7, L59, LC9, LMG, LY5, LS2, LQ9, LQ4, L76, LY6 Throttle Actuator Control (TAC) Module Codes, MIL/SES DTCs P2108, P1516, U0107, Reduced Engine Power (Reprogram PCM)

Models:2006-2007 Cadillac Escalade Models
2006-2007 Chevrolet Avalanche, Express 1500/2500/3500, Silverado, Silverado Flex Fuel, Silverado Hybrid, Silverado SS, Silverado 2500/3500 HD, Suburban, Tahoe, W3500/W4500 Series Medium Duty Tilt Cab
2006-2007 GMC Savana 1500/2500/3500, Sierra, Sierra Flex Fuel, Sierra Hybrid, Sierra Performance Edition, Sierra 2500/3500 HD, Yukon Models, W3500/4500 Series Medium Duty Tilt Cab
2006-2007 HUMMER H2, H2 SUT
with GEN III or GEN IV Vortec V8 4.8L, 5.3L or 6.0L Engine (VINs V, C, B, M, T, Z, 3, 0, J, H, N, U, Y, K -- RPOs LR4, LY2, L33, LH6, LM7, L59, LC9, LMG, LY5, LS2, LQ9, LQ4, L76, LY6)



This bulletin is being revised to add the 2007 model year and engines. Please discard Corporate Bulletin Number 06-06-04-042 (Section 06 -- Engine/Propulsion System).


Condition

Some customers may experience engine operation in the Reduced Engine Power mode, an MIL/SES light on and DTCs P2108, P1516, and U0107 set.

Cause

This condition may be caused by an error in the TAC Module communication software.

Correction

Diagnostics Aids:

    • 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.

Warranty Information

For vehicles repaired under the 8 year/80,000 miles (130,000 kilometers) emission controller warranty, use:

Labor Operation

Description

Labor Time

J6353*

Module, Powertrain Control - Engine Reprogramming with SPS

0.4 hr

*This labor operation number is for bulletin use only. It will not be published in the Labor Time Guide.