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 MANUALSCHEVROLET2006SUBURBAN C2500, 6.0 UREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1228 (CELLULAR SYSTEM, ENTERTAINMENT SYSTEM, AND NAVIGATION SYSTEM)DIAGNOSTIC INFORMATION AND PROCEDURESDTC B125C OR B125DCIRCUIT/SYSTEM TESTING
2006 Chevrolet Suburban C2500, 6.0 U
Circuit/System Testing
2006 Chevrolet Suburban C2500, 6.0 USECTION Circuit/System Testing
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the DRR antenna coax from the radio. Connect the EL-48028 to the radio and place on the roof of the vehicle. See Special Tools .
- Ignition ON, radio tuned to XM. Verify XM reception has improved.
- If the reception is not improved, replace the radio.
- Ignition OFF, disconnect the antenna coaxial from the digital radio antenna.
- Test for less than 5 ohms end to end at the coax center conductor.
- If greater than the specified range, replace the antenna coax.
- Test for less than 5 ohms end to end at the coax outer shield.
- If greater than the specified range, replace the antenna coax.
- Test for infinite resistance between the antenna coax center conductor and the outer shield.
- If less than the specified range, replace the antenna coax.
- If all circuits test normal, replace the digital radio antenna.
IMPORTANT:
Check for the proper operation of the OnStar® System prior to performing this diagnostic. Address any concerns with the OnStar® System prior to diagnosing or repairing the XM radio concern.
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.