C 1500 Truck 2WD V6-4.3L VIN X (2003)
PROM - Programmable Read Only Memory: Customer Interest
Engine Controls - Lack of Power When Hot
Bulletin No.: 05-06-04-077
Date: December 22, 2005
TECHNICAL
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(TM) 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 0111212006. As always, make sure your Tech 2(R) is updated with the latest software version.
Warranty Information
For vehicles repaired under warranty use the table.
Disclaimer
