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.
Circuit/System Testing
- Ignition OFF, disconnect the navigation antenna coax cable connector at the A11 Radio. Connect the EL-49903 GM OnStar antenna diagnostic tool kit to the A11 Radio, place the test antenna on the roof of the vehicle.
- Ignition ON, radio ON, navigation selected.
- Verify DTC B2462 is not set.
- If DTC B2462 is set
Replace the A11 Radio.
- If DTC B2462 is not set
- If DTC B2462 is set
- Ignition OFF, disconnect the radio navigation coax cable at the T15 Navigation Antenna Signal Splitter.
- Verify the radio navigation coax cable passes the coax cable component test. Refer to Component Testing .
- If the coax cable does not pass the test
Replace the coax cable
- If the coax cable passes the test
- If the coax cable does not pass the test
- Test or replace the T15 Navigation Antenna Signal Splitter.
Use the Manual With the Right Hardware
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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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