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Home >> Cadillac >> 2014 >> SRX Base >> Repair and Diagnosis >> Engine Performance >> System >> Data Communication System >> Diagnostic Information and Procedures >> DTC U18A6: Lost Communication with Right Object Detection Control Module >> Circuit/System Testing
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Circuit/System Testing

NOTE:

Use the schematics and connector end views to identify the device's ground, B+, and serial data circuit terminals.

  1. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. It may take up to 2 min for all vehicle systems to power down. Disconnect the harness connector at the B218R Side Object Sensor Module - Right.
  2. Test for less than 10 Ω between each ground circuit terminal and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  3. Ignition ON.
  4. If equipped, verify a test lamp illuminates between each B+ circuit terminal and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF.
    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, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF.
    2. 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 B218R Side Object Sensor Module - Right.
    • If the test lamp illuminates 
  5. Ignition ON.
  6. If equipped, test for at least 6 V between the communication enable circuit terminal and ground.
    • If less than 6 V 
    1. Ignition OFF, disconnect the harness connectors at the B218L Side Object Sensor Module - Left.
    2. Test for infinite resistance between the communication enable circuit terminal 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 communication enable circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the B218L Side Object Sensor Module - Left.
    • If 6 V or greater 
  7. Ignition OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. It may take up to 2 min for all vehicle systems to power down. Disconnect the harness connector at the B218L Side Object Sensor Module - Left.
  8. Test for less than 1 V between each serial data circuits and ground.
    • If 1 V or greater 

      Repair the short to voltage in the serial data circuit.

    • If less than 1 V 
  9. Test for infinite resistance between each serial data circuits and ground.
    • If less than infinite resistance 

      Repair the short to ground in the serial data circuit.

    • If infinite resistance 
  10. Test for infinite resistance between 2 serial data circuits.
    • If less than infinite resistance 

      Repair the short together between the serial data circuits.

    • If infinite resistance 
  11. Test for less than 2 Ω in each of the serial data circuits end to end between the B218L Side Object Sensor Module - Left and the B218R Side Object Sensor Module - Right.
    • If 2 Ω or greater 

      Repair the open/high resistance in the serial data circuit.

    • If less than 2 Ω 
  12. Replace the B218R Side Object Sensor Module - Right.
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