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.
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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1779 (DATA COMMUNICATION SYSTEM)DIAGNOSTIC INFORMATION AND PROCEDURESDIAGNOSTIC CODE INDEX
2003 Chevrolet TrailBlazer 4.2 S, 4WD
Diagnostic Code Index
2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Diagnostic Code Index
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
DIAGNOSTIC CODE INDEX
| DTC | Description |
|---|---|
| DTC B1000 | Electronic Control Unit (ECU) Performance |
| DTC B1001 | Option Configuration Error |
| DTC U0073 | High Speed CAN Communication Bus |
| DTC U0100-U0299 | Lost Communication With XXXX Control Module |
| DTC U1000 | Class 2 Data Link Malfunction |
| DTC U1001-U1254 | Lost Communication With XXXX Control Module |
| DTC U1300, U1301, or U1305 | Class 2 Data Link |
| DTC U2100 | Controller Area Network (CAN) Bus Communication |
| DTC U2102 or U2103 | More/Fewer Controllers On Bus Than Programmed |
| DTC U2104 | Controller Area Network (CAN) Bus Reset Counter Overrun |
| DTC U2105-U2199 | Lost Communication With XXXX Control Module |
RENDER: 1.0x
NO RELATED
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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.