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Home >> Hummer >> 2010 >> H3 Alpha >> Repair and Diagnosis >> External Pages >> Different car >> Section 1913 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> DTC B125C >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
  1. 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.
  2. 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.
  3. Ignition OFF, reconnect the antenna coax cable at the A11 radio. Disconnect the antenna coax cable from the T4G antenna.
  4. 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.
  5. If all circuits test normal, replace the T4G antenna.
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