Sierra 1500 2WD V8-5.3L Hybrid (2004)
Relays and Modules - Hybrid Drive: By Symptom
Engine Controls - DTC's P1A4B or P1AB2 (42V Faults)
Bulletin No.: 04-06-03-013A
Date: May 19, 2005
INFORMATION
Subject:
Hybrid - DTC P1A4A, P1A4B, P1AB2, P1AAE, B140C or AP0 System Fault DIC Message (Software Update)
Models:
2004-2005 Chevrolet Silverado
2004-2005 GMC Sierra
with RPO HP2 - Hybrid Vehicle
Supercede:
This bulletin is being revised to expand the DTCs involved and provide updated calibration information. Please discard Corporate Bulletin Number
04-06-03-013 (Section 06 - Engine/Propulsion System).
Changes have been made to the ESCM and SGCM software that will reduce the 42V correlation faults being set. If the vehicle has set either DTC
P1A4A, P1A4B P1AB2, P1AAE, B140C or an AP0 System Fault DIC Message, use the following procedure to verify the ESCM and SGCM calibration
information.
1.
BEFORE REPLACING ANY MODULES, use the steps to verify that the ESCM and SGCM contain the latest software calibration.
Important:
Both the ESCM and SGCM must have up to date calibrations.
2.
If the ESCM and/or SGCM do not have the latest software, use the Tech 2(R) SPS function to update the module(s) and clear all DTCs. The latest
software is available on TIS version 4.5, broadcast to dealers in April, 2005.
3.
If BOTH the ESCM and SGCM were equipped with the latest calibrations at the time the vehicle came in for service, replace the appropriate
module according to the DTC that was set:
^
P1A4A = ESCM Hybrid Battery Current Sensor Circuit
^
P1A4B = ESCM Hybrid Battery Current Sensor Performance