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 MANUALSGMC2013SIERRA 3500 HD WT, 2D PICKUP, 6.0L ENG VIN G, RWD, GASREPAIR AND DIAGNOSIS (SINGLE PAGE)ACCESSORIES & EQUIPMENTENTERTAINMENT SYSTEMSCELLULAR SYSTEM, ENTERTAINMENT SYSTEM, AND NAVIGATION SYSTEMDIAGNOSTIC INFORMATION AND PROCEDURESDTC B125CCIRCUIT/SYSTEM TESTING
2013 GMC Sierra 3500 HD WT, 2D Pickup, 6.0L Eng VIN G, RWD, Gas
Circuit/System Testing
2013 GMC Sierra 3500 HD WT, 2D Pickup, 6.0L Eng VIN G, RWD, GasSECTION Circuit/System Testing
- Ignition OFF, disconnect the digital radio antenna coax cable from the A11 radio. Connect the EL-48028 to the radio and place on the roof of the vehicle.
- Ignition ON, radio tuned to XM channel 1. Verify DTC B125C is not set as current and XM reception is improved.
- If DTC B125C is set as current or the reception is not improved, replace the A11 radio.
- Ignition OFF, reconnect the antenna coax cable at the A11 radio. Disconnect the antenna coax cable from the T4G antenna.
- Ignition ON, radio ON, test for 4.5-5.5 V between the antenna coax cable center terminal and an outer shield.
- If less than the specified range, test the antenna coax cable for an open/high resistance or a short to ground.
- If greater than the specified range, test the antenna coax cable for a short to voltage.
- If all circuits test normal, replace the T4G antenna.
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.