LU3 May Lack Power at High Ambient Temperatures Only (If Necessary, Reprogram PCM with New Service Calibration)
| Subject: | Lack of Power (LU3 Engine) at High Ambient Temperatures Only (If Necessary, Reprogram PCM with New Service Calibration) |
| Models: | 2003-2005 Chevrolet Astro, Blazer, Express, S-10, Silverado |
| 2003-2005 GMC Jimmy, Safari, Savana, Sierra, Sonoma |
| with 4.3L Vortec™ V6 Engine (VIN X -- RPO LU3) |
Condition
Some customers may comment that the vehicle may exhibit a lack of power at high ambient temperatures.
Cause
Engineering has identified a concern with the PCM software. In high ambient temperatures, the engine control management system may falsely retard the timing, causing a noticeable loss of power.
Correction
Important: Before Reprogramming the PCM, verify the customer concern. Refer to SI Engine Controls and under Diagnostic Information and Procedures. Refer to Lack of Power, Sluggishness, or Sponginess for the cause of the low power condition at high ambient temperatures. If no trouble is found, then reprogram the PCM.
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 12.5, which was broadcast to dealers on 12/11/2005. For the dealerships that use CDs, the CD version will be 1.0 for 2006, which will be mailed 01/12/2006. As always, make sure your Tech 2® is updated with the latest software version.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J6354 | Module, Powertrain Control - Engine Reprogramming w/SPS | Use Published Labor Operation Time |
