Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Chevrolet Express 1/2 Ton Van V6-4.3L VIN XFACTORY OEM SERVICE PROCEDURE
Engine Controls/Electrical - MIL ON/DTC's/Driveability
Bulletin No.: 04-06-04-028
Date: April 22, 2004
TECHNICAL
Subject:
Various Driveability Concerns, Check Engine Light On, DTCs Set (Repair Wire Harness)
Models:
2003-2004 Chevrolet Express Van
2003-2004 GMC Savana Van
Condition
Some customers may comment on various driveability or engine performance concerns and that the check engine light is illuminated.
These conditions may occur intermittently and diagnosis may find various DTCs set.
Cause
The cause of these conditions may be the PCM wire harness chaffing on the left side suspension upper control arm forward bracket.
Correction
Raise the front left side of the vehicle and inspect the PCM wire harness as it routes over the control arm. The harness may come in contact with the forward upper control arm bracket and chaffing may occur as the vehicle goes over bumps. If wire chaffing is found, follow published wire repair procedures in SI and tie strap the harness out of the way so it does not contact the sharp edges of the bracket.
Warranty Information
For vehicles repaired under warranty, use the table shown.
Disclaimer
Date: April 22, 2004
TECHNICAL
Subject:
Various Driveability Concerns, Check Engine Light On, DTCs Set (Repair Wire Harness)
Models:
2003-2004 Chevrolet Express Van
2003-2004 GMC Savana Van
Condition
Some customers may comment on various driveability or engine performance concerns and that the check engine light is illuminated.
These conditions may occur intermittently and diagnosis may find various DTCs set.
Cause
The cause of these conditions may be the PCM wire harness chaffing on the left side suspension upper control arm forward bracket.
Correction
Raise the front left side of the vehicle and inspect the PCM wire harness as it routes over the control arm. The harness may come in contact with the forward upper control arm bracket and chaffing may occur as the vehicle goes over bumps. If wire chaffing is found, follow published wire repair procedures in SI and tie strap the harness out of the way so it does not contact the sharp edges of the bracket.
Warranty Information
For vehicles repaired under warranty, use the table shown.
Disclaimer
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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