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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2001CHEVY EXPRESS G2500, VAN CARGO EXTENDED, 5.7 R, L31/KL8REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 426 (DATA LINK COMMUNICATIONS SYSTEM)DIAGNOSTIC INFORMATION AND PROCEDURESDTC U1001 TO U1254: MODULE U1XXX COMMUNICATIONNOTES
2001 Chevrolet Chevy Express G2500, Van Cargo Extended, 5.7 R, L31/KL8
DTC U1001 to U1254: Module U1XXX Communication: Notes
2001 Chevrolet Chevy Express G2500, Van Cargo Extended, 5.7 R, L31/KL8SECTION Notes
WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
When more than one Loss of Communication DTC is set in either one module or in several modules, diagnose the DTCs in the following order:
- Current DTCs before history DTCs unless told otherwise in the diagnostic tables.
- The DTC which is reported the most times.
- From the lowest number DTC to the highest number DTC.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.