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Home >> Cadillac >> 2017 >> CT6 Plug-In >> Repair and Diagnosis (Single Page) >> Electrical >> Body Electrical >> Power Outlets >> Diagnostic Information and Procedures >> DTC B151E: Accessory DC/AC Power Inverter Module Relay Circuit >> Circuit/System Testing
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Circuit/System Testing

WARNING: To help avoid personal injury, always treat the accessory power receptacle, accessory DC/AC power inverter module, AC circuit wires and connectors as if AC high-voltage is present.
  1. Ignition OFF/Vehicle OFF and all vehicle systems OFF, disconnect the KR80 Accessory Relay, ignition ON.
  2. Verify a test lamp illuminates between the B+ circuit terminal 87 and ground.
    • If the test lamp does not illuminate 

      Replace the X53A Fuse Block - Rear Body

    • If the test lamp illuminates 
  3. Verify a test lamp illuminates between the ignition circuit terminal 86 and ground.
    • If the test lamp illuminates 
  4. Ignition OFF/Vehicle OFF and all vehicle systems OFF, nothing plugged into the X81 Accessory Power Receptacle. Disconnect the X1 and X2 harness connectors at the T1 Accessory DC/AC Power Inverter Module.
  5. Connect the KR80 Accessory Relay, ignition ON.
  6. Verify a test lamp illuminates between the relay control circuit terminal 4 X2 and ground.
    • If the test lamp does not illuminate 
    1. Ignition OFF/Vehicle OFF, remove the test lamp.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the KR80 Accessory Relay.
    • If the test lamp illuminates 
  7. Ignition ON/Vehicle in Service Mode, connect a test lamp between T1 Accessory DC/AC Power Inverter Module connector B+ circuit terminal 1 X1 and ground.
  8. Ignition ON/Vehicle in Service Mode, connect a 7.5 A fused jumper wire between the T1 Accessory DC/AC Power Inverter Module connector control circuit terminal 4 X2 and ground. Verify the test lamp illuminates.
    • If the test lamp does not illuminate and the fuse is good 
    1. Ignition OFF/Vehicle OFF, remove the test lamp and fused jumper.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the KR80 Accessory Relay.
      • If the test lamp does not illuminate and the fuse is open 
    3. Ignition OFF/Vehicle OFF, remove the test lamp and fused jumper.
    4. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the T1 Accessory DC/AC Power Inverter Module.
    • If the test lamp illuminates 
  9. Test or replace the T1 Accessory DC/AC Power Inverter Module.
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