ASE A6 Electrical Electronics Practice Test

Door lock circuit.

51. The power door locks in the vehicle in the diagram above unlock only. There is no locking action. Which of the following is causing this condition?

  • A. Relay A
  • B. Relay B
  • C. Switch A
  • D. Fuse A


Door lock circuit.

Answer A is correct. Relay A, the lock relay is faulty.

Answer B is wrong. The vehicle's doors unlock OK, indicating that the unlock relay functions. Relay A, the lock relay and its circuit should be inspected further for an electrical problem.

Answer C is wrong. It is doubtful that both switches are faulty. Inspect the door lock relay; the contacts are stuck open, or the coil is faulty, and the relay needs replacement.

Answer D is wrong. Fuse A affects the power feed to the relay coils.