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Home >> Buick >> 2012 >> Regal Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 227 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> DTC B1287 >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2011 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the X1 harness connector at the T3 amplifier.
  2. Ignition ON, radio ON, mute OFF, test for less than 1 V between the amplifier control circuit terminal 37 and ground.
    • If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.
  3. Mute ON, test for 7.5-8.5 V between the amplifier control circuit terminal 37 and ground.
    • If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the A11 radio.
    • If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.
  4. If all circuits test normal, replace the T3 amplifier.
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