ASE A6 Electrical Electronics Practice Test

Door lock circuit.

6. 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 is functioning. Relay A, the lock relay and it's circuit should be inspected further for an electrical problem.

Answer C is wrong. It is doubtful that both switches are faulty and will not lock the doors. Inspect the door lock relay, it's contacts are probably stuck open or it's coil is faulty and it just needs to be replaced.

Answer D is wrong. Fuse A would affect the power feed to the relay coils. These relays are switched by a positive pulse from the switches.