CAA Automotive Systems and Parts 3 — Questions and Answers
Question 1: What does an OBD-II diagnostic port allow an appraiser to check?
- Tire tread depth
- Paint thickness
- Stored trouble codes and readiness monitors (Correct answer)
- Frame straightness
Correct answer: Stored trouble codes and readiness monitors
The OBD-II port provides access to stored diagnostic trouble codes and emissions readiness monitor status.
Question 2: OBD-II became mandatory on all new light-duty vehicles sold in the United States beginning with which model year?
- 1990
- 1994
- 1996 (Correct answer)
- 2001
Correct answer: 1996
OBD-II was required on all U.S. cars and light trucks starting with the 1996 model year.
Question 3: Which component in an automatic transmission transfers engine power to the transmission through fluid coupling?
- Clutch disc
- Torque converter (Correct answer)
- Flywheel
- Planetary gear set
Correct answer: Torque converter
The torque converter uses transmission fluid to couple the engine to the transmission and multiply torque.
Question 4: Dark brown transmission fluid with a burnt smell found during an appraisal inspection typically indicates what?
- Normal fluid condition
- Overheated or degraded fluid and possible internal wear (Correct answer)
- Coolant contamination
- Recently serviced transmission
Correct answer: Overheated or degraded fluid and possible internal wear
Healthy ATF is usually red or pink; dark, burnt-smelling fluid signals overheating and likely internal wear.
Question 5: A milky, light-brown substance on the underside of the oil filler cap most likely indicates which problem?
- Coolant mixing with engine oil (Correct answer)
- Fuel dilution of oil
- Normal oil oxidation
- Low oil level
Correct answer: Coolant mixing with engine oil
A milkshake-like residue usually means coolant is contaminating the oil, often from a head gasket or cracked head.
Question 6: Which braking component converts hydraulic pressure into clamping force on a disc brake system?
- Master cylinder
- Brake booster
- Caliper (Correct answer)
- Proportioning valve
Correct answer: Caliper
The caliper's pistons receive hydraulic pressure and squeeze the pads against the rotor.
Question 7: What is the main purpose of an anti-lock braking system (ABS)?
- Shorten stopping distance on all surfaces
- Prevent wheel lockup so the driver maintains steering control (Correct answer)
- Reduce brake pad wear
- Automatically apply brakes in an emergency
Correct answer: Prevent wheel lockup so the driver maintains steering control
ABS modulates brake pressure to keep wheels from locking, preserving steering control during hard braking.
CAA Automotive Systems and Parts 3
What does an OBD-II diagnostic port allow an appraiser to check?