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Home >> Cadillac >> 2021 >> XT5 Sport >> Repair and Diagnosis >> External Pages >> Different car >> Section 734 (Keyless Entry System And Remote Functions) >> Diagnostic Information and Procedures >> DTC B305D >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the X1 electrical connector at the K84 Keyless Entry Control Module and the X4 electrical connector at the K9 Body Control Module
  2. Test circuit 4086 from end to end for less than 10 Ω
    • If 10 Ω or greater, repair the open/high resistance on the circuit
    • Go to next step: If less than 10 Ω
  3. Test circuit 4086 between X1 terminal 10 and ground
    • If continuity, repair the short to ground
    • Go to next step: If infinite resistance
  4. Test circuit 4086 for short to voltage end to end
    • If voltage is present
    • Go to next step: Repair the short to voltage on the circuit
  5. Ignition OFF, connect the X1 electrical connector at the K84 Keyless Entry Control Module
  6. Using a DMM between X4 terminal 25 and ground, verify the K84 Keyless Entry Control Module is grounding the circuit when Keyless Entry is requested by pressing the transmitter
    • If infinite resistance, replace the K84 Keyless Entry Control Module
    • Go to next step: If a ground is present
  7. Replace the K9 Body Control Module