ASE Practice Test (B5: Mechanical & Electrical Components) — Questions and Answers
Question 1: After a collision repair, a vehicle's steering pulls to the right. The technician checks the front alignment and finds the right front caster is significantly less than the left. The MOST likely cause is:
- A bent steering rack
- A damaged or displaced strut tower or control arm mounting point (Correct answer)
- Improper tire inflation on the right front
- A seized right front brake caliper
Correct answer: A damaged or displaced strut tower or control arm mounting point
Caster angle is determined by the geometry of the strut tower and lower control arm pivot points. If a collision has shifted or damaged these mounting points, caster will be altered on that corner. Unequal caster side-to-side causes the vehicle to pull toward the side with less positive caster.
Question 2: A refrigerant recovery/recycling/recharging machine must be used when servicing an A/C system after a collision because:
- It is recommended but not legally required
- Federal law prohibits venting refrigerants into the atmosphere (Correct answer)
- Refrigerant must be replaced after any impact regardless of leaks
- The machine purges moisture that enters during the collision
Correct answer: Federal law prohibits venting refrigerants into the atmosphere
Section 608 of the Clean Air Act prohibits the intentional venting of refrigerants (R-134a, R-1234yf) into the atmosphere. Technicians must use certified recovery equipment before opening any A/C system. Violators face significant EPA fines.
Question 3: After repairing a vehicle involved in a frontal collision, the technician notices the electric power steering (EPS) warning light is on. The MOST likely cause is:
- Low power steering fluid level
- A damaged or misaligned steering angle sensor (Correct answer)
- Incorrect front toe setting
- A blown fuse in the EPS motor circuit
Correct answer: A damaged or misaligned steering angle sensor
The steering angle sensor (SAS) is a critical input for EPS, stability control, and other ADAS systems. If the sensor was damaged in the collision or the steering column was disturbed, the SAS will be out of calibration and trigger a warning light. The SAS must be recalibrated after any alignment or steering repair.
Question 4: A SRS (airbag) system clock spring must be replaced if:
- The steering wheel was removed during the repair (Correct answer)
- Any front airbag has deployed
- The vehicle was involved in any collision regardless of airbag deployment
- The battery was disconnected for more than 30 minutes
Correct answer: The steering wheel was removed during the repair
The clock spring (or spiral cable) is a rotating electrical connector in the steering column. It must be replaced if the steering wheel was removed without proper locking procedures to prevent over-rotation and ribbon cable damage. It is a standard required replacement when removing the wheel.
Question 5: A technician is replacing a damaged radiator after a collision. After installation, the cooling system should be:
- Filled with straight water to test for leaks before adding coolant
- Pressure-tested, then filled with the OEM-specified coolant type and concentration
- Filled with universal long-life coolant regardless of OEM specification
- Vacuum-filled using a cooling system refill tool to purge air pockets (Correct answer)
Correct answer: Vacuum-filled using a cooling system refill tool to purge air pockets
Modern cooling systems, especially those with complex passages and multiple heater circuits, are best refilled using a vacuum fill tool. This method evacuates air from the system and draws coolant in without air pockets, preventing overheating caused by trapped air. The correct OEM coolant specification must always be used.
Question 6: After completing a collision repair involving deployment of side curtain airbags, which of the following must be performed before returning the vehicle to the customer?
- Road test only — airbag systems are self-diagnosing after battery reconnect
- SRS system scan, replacement of all deployed modules, and verification of no stored fault codes (Correct answer)
- Replace only the airbag modules — sensors and wiring are reusable
- Clear all SRS codes with a scan tool and verify the MIL is off
Correct answer: SRS system scan, replacement of all deployed modules, and verification of no stored fault codes
After any airbag deployment, all deployed modules (airbags, pretensioners) must be replaced. A full SRS system scan must be performed to identify any damaged sensors, wiring, or control modules. The system must be verified fault-code free before delivery to ensure it will function in a future collision.
ASE Practice Test (B5: Mechanical & Electrical Components)
After a collision repair, a vehicle's steering pulls to the right.
The technician checks the front alignment and finds the right front caster is significantly less than the left.
The MOST likely cause is: