ASE Practice Test (B5: Mechanical & Electrical Components) 3 — Questions and Answers
Question 1: After replacing a driver's side mirror housing, the power mirror does not adjust. A test light confirms power and ground at the mirror connector. What should the technician check next?
- Replace the mirror switch on the door panel
- Verify the mirror motor and actuator connections inside the new housing are properly connected (Correct answer)
- Check the body control module for DTCs
- Test the mirror fuse with a voltmeter
Correct answer: Verify the mirror motor and actuator connections inside the new housing are properly connected
New replacement mirror housings sometimes have the internal motor wiring harness improperly connected at the factory, or connectors may not fully seat during installation. Since power and ground are confirmed at the external connector, the fault is inside the mirror assembly. The technician should open the mirror housing and verify the internal motor connector is properly seated before condemning the motor or other components.
Question 2: What type of sensor is commonly used in a power seat memory system to detect and store seat position?
- Piezoelectric pressure sensor
- Hall-effect or resistive position (potentiometer) sensors on each axis of movement (Correct answer)
- Infrared proximity sensor
- Accelerometer
Correct answer: Hall-effect or resistive position (potentiometer) sensors on each axis of movement
Power seat memory systems track seat position using sensors on each adjustable axis (fore/aft, height, recline). Hall-effect sensors (which detect magnetic position) or resistive potentiometers (variable resistance based on position) report seat location to the memory module. When a driver profile is recalled, the module drives the motors until the sensors confirm the stored position is reached.
Question 3: A technician is replacing a door beam (intrusion bar) after a side impact. Which of the following statements about this repair is correct?
- The door beam is cosmetic and can be fabricated from any steel
- The door beam must be replaced with an OEM part or approved replacement — it is a safety component that must meet original strength specifications (Correct answer)
- Any steel bar of similar size can be welded in as a substitute
- The beam should be straightened and re-installed if only mildly bent
Correct answer: The door beam must be replaced with an OEM part or approved replacement — it is a safety component that must meet original strength specifications
Door intrusion beams are engineered safety components designed to resist side-impact intrusion into the passenger compartment. They must be replaced with OEM or approved equivalent parts. Substituting unapproved materials, fabricating replacements, or straightening bent beams will not restore the original crash protection. A repair done incorrectly may pass visual inspection but fail to protect occupants in a subsequent side impact.
Question 4: When replacing a convertible top, what adjustment is critical to prevent water leaks along the windshield header?
- Adjusting the top bow height only
- Adjusting the front header latch tension and alignment so the top seals evenly along the full width of the windshield frame (Correct answer)
- Lubricating the top mechanism with white grease
- Replacing the windshield with a taller OEM unit
Correct answer: Adjusting the front header latch tension and alignment so the top seals evenly along the full width of the windshield frame
Convertible top water leaks at the windshield header are typically caused by incorrect header latch adjustment. The latches must pull the front bow down with sufficient and even tension to compress the weatherstrip uniformly across the full width of the windshield frame. If one side is looser than the other, water will track along the header and enter the cabin. Adjustment is made at the latch striker or the latch mechanism itself.
Question 5: A vehicle's heated seat element is not working on one side. The seat switch and fuse test normal. What is the MOST likely cause?
- Failed body control module
- Open circuit in the heating element mat due to a broken wire in the seat cushion (Correct answer)
- Shorted seat position sensor
- Failed HVAC blend door actuator
Correct answer: Open circuit in the heating element mat due to a broken wire in the seat cushion
Heated seat elements are resistive wire mats embedded in the seat cushion. Repeated bending and flexing of the seat as passengers sit and stand eventually breaks one of the resistance wires, creating an open circuit. With the fuse and switch confirmed good, measuring resistance across the element will show infinity (open) on the failed side instead of the expected resistance value. Replacement of the heating element mat is required.
Question 6: After a rear collision repair, the backup camera displays a distorted image. The camera body appears undamaged. What is the MOST likely cause?
- Failed radio/head unit display
- Damaged or pinched camera wiring harness in the repaired area causing signal degradation (Correct answer)
- Depleted backup camera battery
- Incorrect camera angle adjustment only
Correct answer: Damaged or pinched camera wiring harness in the repaired area causing signal degradation
Backup cameras use video signal cables that run from the camera (usually in the tailgate, license plate area, or bumper) through the vehicle to the display. During rear collision repair and panel replacement, the camera wiring harness can be pinched, cut, or stressed, degrading the video signal. A damaged coaxial video cable or twisted-pair signal wire will produce a distorted, snowy, or rolling image. Inspecting the harness routing through the repaired area is the first diagnostic step.
ASE Practice Test (B5: Mechanical & Electrical Components) 3
After replacing a driver's side mirror housing, the power mirror does not adjust.
A test light confirms power and ground at the mirror connector.
What should the technician check next?