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 MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 15 (BODY CONTROL MODULES)SELF-DIAGNOSTIC SYSTEMCELLULAR COMMUNICATION SYSTEM DIAGNOSTIC SYSTEM CHECK
2003 Chevrolet TrailBlazer 4.2 S, 4WD
Cellular Communication System Diagnostic System Check
2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Cellular Communication System Diagnostic System Check
WARNING: This page is about a different car, the 2002 Chevrolet Monte Carlo, 2002 Chevrolet Impala, 2001 Chevrolet Monte Carlo, and 2001 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Use this check as starting point for any cellular communication system complaint.
- Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to TEST D: SCAN TOOL DOES NOT POWER UP under SYSTEM TESTS.
- Turn ignition switch to RUN position. Using scan tool, attempt to establish communications with Vehicle Interface Unit (VIU). If communication is established, go to next step. If communication cannot be established, go to TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS.
- Select VIU DTCS function on scan tool. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair as necessary.
- Using scan tool, check for DTCs U1000-U1305. If DTCs are present, go to next step. If DTCs are not present, go to step 6.
- Check for DTC B1500. If DTC is present, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . Repair as necessary. If DTC B1500 is not present, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . Repair as necessary.
- Check for DTCs B1000, B1004, B1007 or B1009. If DTCs are not present, go to next step. If any DTC is present, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . Repair as necessary.
- Check for DTCs B1327 or B1328. If DTCs are not present, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If DTCs are present, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . Repair as necessary.
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.