ASE A6 Electrical Electronics Practice Test
51. The power door locks on 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. The door lock system unlocks the doors, indicating that the unlock relay is functioning. The lock relay or it's circuit is at fault.
Answer C is wrong. It is doubtful that both switches will not lock the door. Inspect the door lock relay, it's probably stuck open.
Answer D is wrong. Fuse A would affect the power feed to the relay coils. These relays are switched by a positive pulse.
52. Two technicians are discussing diagnostics and the data link connector. Technician A says the OBD II DLC connector is located 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 technician A and B are correct. The connector contains 16 slots, but they are not all standard, some are left to 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. A CAN controller area network is being discussed. Which of the following statements are correct?
- A. The CAN now operates at 1Mbps.
- B. The CAN contains twisted wires to prevent RFI interference.
- C. The low speed CAN connects to the ECM and the TCM.
- D. The high speed CAN connects to the mirror and seat controller.
Answer A is wrong. The CAN system contains different classes or network speeds according to the controller. 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.
54. A vehicle is overheating. The electric radiator cooling fan in the illustration does not operate under any condition. All of the following answers result in an inoperative fan motor EXCEPT?
- A. A short to ground at point A of the system.
- B. An open at point B in the system.
- C. An open at point C in the system.
- D. An open at point D of the system.
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. An open at point B results in no fan operation because the fuse element is open.
Answer C is wrong. An open at point C results in no fan operation because the fan motor is not receiving power.
Answer D is wrong. An open at point D will prevent fan motor operation because it removes the circuit’s ground.
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 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 high current in excess of 100 amps to operate the starter motor and power engine systems during cranking and starting.