Silverado 3500 2WD V8-6.0L (2007)
PROM - Programmable Read Only Memory: Customer Interest
Engine Controls - Engine Sag Shifting Into Drive/Reverse
Bulletin No.: 07-06-04-007
Date: March 05, 2007
TECHNICAL
Subject:
LY6 Cold Start Idle Concern, Engine Sags While Shifting Into Drive or Reverse (Reprogram PCM)
Models:
2007 Chevrolet Silverado HD
2007 GMC Sierra HD
with Vortec(TM) 6.0L V8 Engine (VIN K - RPO LY6)
Condition
Some customers may comment that the vehicle's engine sags while shifting into drive or reverse when it is cold outside.
Cause
The powertrain control module (PCM) calibration may allow the vehicle's engine idle to sag when the engine coolant temperatures are around 8°C (47°
F) while shifting into drive or reverse.
Correction
Reprogram the PCM with the updated calibration.
Due to the length of this programming event, we strongly recommend the following precautions:
Before reprogramming, check the battery condition to prevent a reprogramming error of any of the modules due to battery discharge. Battery voltage
must be between 12 and 16 volts during reprogramming. If the vehicle battery is not fully charged, use jumper cables from an additional battery. Be sure
to turn off or disable any system that may put a load on the battery, such as automatic headlamps, daytime running lights, interior lights, heating,
ventilation, and air conditioning (HVAC) system, radio, engine cooling fan, etc. A programming failure or control module damage may occur if battery
voltage guidelines are not observed.
To maintain battery voltage during programming, make sure you are using an approved battery charger such as the Midtronics Charger, PSC 300 or
PSC550. You may also use a fully charged jumper pack (not connected to AC outlet) as a supplemental source.
The ignition switch must be in the proper position. The Tech 2(R) will prompt you to turn the ignition ON, with the engine OFF. DO NOT change the
position of the ignition switch during the programming procedure unless instructed to do so.
If you experience programming issues utilizing the Pass-Thru method, please reattempt using the remote method with the Tech 2(R) and a "CANDi"
module. If you are still experiencing programming issues, please call the Techline Customer Support Center for assistance.
An updated PCM calibration is now available to address this concern. This calibration, or any that follow, is designed to address this concern.
Reprogram the PCM with the software now available in TIS2WEB using the Service Programming System (SPS). Use data version 2.5 for 2007 or later,
available on TIS2WEB (website version of TIS) February 18, 2007; and on TIS DVD version 3.0 /2007 or later, mailed to dealers beginning March 14,
2007.
If you cannot access the calibration, call the Techline Customer Support Center and it will be provided. As always, make sure your Tech 2(R) Diagnostic
Scan Tool is updated with the latest software version.
DTCs may be set during programming and additional reprogramming time is required for downloading the operation files with the calibration files.
Clear any codes and verify the condition has been fixed.
Warranty Information
