ASE A6 Electrical Electronics Practice Test

Diagram of 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


Answer A is correct. The lock relay is faulty.

Answer B is wrong. Answer A is correct.

Answer C is wrong. It is doubtful that both switches will not lock the door.

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

52. Two technicians discuss diagnostics and the data link connector. Technician A says the OBD II DLC connector is in the cabin near the steering wheel. Technician B says to use this connector to test resistance in the CAN (Controller Area Network). Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B


Answer A is wrong. Both technicians A and B are correct. The connector contains 16 slots, but they are not all standard; some are left to the manufacturer's discretion. They are located in the passenger's compartment near the steering wheel. OBD I connectors may be located elsewhere.

Answer B is wrong. Use pins 6 and 14 to test resistance in the controller area network.

Answer C is correct. Both A and B are correct.

Answer D is wrong. Both A and B are correct.

53. Which of the following statements about the CAN controller area network is correct?

  • A. All CAN networks operate at 1Mbps.
  • B. The CAN bus contains twisted wires to prevent RFI interference.
  • C. The ECM and the TCM connect to the low-speed controller area network.
  • D. The mirror and seat controller connect to the high-speed controller area network.


Answer A is wrong. Different networks have different classes and speeds. Different controller messages have priority or dominance over other recessive messages.

Answer B is correct. Twisted pair and shielded wiring prevent RFI and MFI interference.

Answer C is wrong. Answer B is correct.

Answer D is wrong. Answer B is correct.

Click to Enlarge.

54. An engine is overheating. The electric radiator cooling fan in the illustration does not operate under any condition. All of the following result in this condition EXCEPT:

  • A. A short to ground at point A.
  • B. An open at point B.
  • C. An open at point C.
  • D. An open at point D.


Answer A is correct. All the other answers result in an inoperative fan motor. A short to ground at point A causes the fan motor to operate whenever the ignition is switched ON.

Answer B is wrong. Answer A is correct.

Answer C is wrong. Answer A is correct.

Answer D is wrong. Answer A is correct.

55. All of the following are true statements about a fully charged lead acid battery EXCEPT:

  • A. It acts as a capacitor smoothing current.
  • B. It powers the accessories while the engine is running.
  • C. The electrolyte has a specific gravity of 1.265
  • D. It powers the starter while the engine is cranking.


Answer A is wrong. Due to the nature of their design, batteries act as capacitors, smoothing A/C current and alternator ripple.

Answer B is correct. This is an EXCEPT type question. Once the engine starts, the charging system takes over and provides power for all accessories.

Answer C is wrong. The electrolyte of a good battery has a specific gravity of ~1.265.

Answer D is wrong. It provides a high current above 100 amps to operate the starter motor and power engine systems during cranking and starting.