Vehicle Systems and Identification Flashcards

A customer is booking a recall check, and the service consultant needs the vehicle's model year. Which VIN position should the consultant look at?

Answer: 10th character

On VINs used since 1981, the 10th character is the model-year code. For example, "L" in that position means a 2020 model year.

A customer reads the VIN to a service consultant over the phone and says one of the characters is the letter "O." What should the consultant conclude?

Answer: The character is really a zero, because I, O and Q are not used in VINs

Standard 17-character VINs never use the letters I, O or Q because they are too easy to confuse with the numbers 1 and 0. The character must be the number zero.

A warranty claim needs the vehicle's month and year of manufacture. Where is this information most reliably found?

Answer: The safety certification label on the driver's door jamb or B-pillar

The FMVSS certification label, usually on the driver's door jamb or B-pillar, shows the month and year of manufacture. The VIN shows the model year, which can differ from the build date.

Which VIN character tells a service consultant the country where the vehicle was manufactured?

Answer: The 1st character

The first character of the VIN identifies the country or region of manufacture. For example, 1, 4 and 5 mean the United States, 2 means Canada, 3 means Mexico and J means Japan.

A hybrid customer asks what the bright orange cables under the hood are. What is the best explanation?

Answer: They are high-voltage cables that only trained technicians should handle

Industry practice (SAE J1673) uses orange cables or sheathing to mark high-voltage circuits on hybrid and electric vehicles. They carry dangerous voltage between the battery pack, the inverter and the motor-generators.

On a hybrid or electric vehicle, what is the main job of the inverter?

Answer: To convert the battery's high-voltage DC into AC to drive the traction motor, and to convert AC back to DC during regeneration

The high-voltage battery stores DC, but most traction motors run on three-phase AC. The inverter converts DC to AC for driving and changes AC back to DC to recharge the battery during regenerative braking.

A customer with a front-wheel-drive car complains of a rhythmic clicking noise during sharp turns while accelerating. Which component is the most likely cause?

Answer: Outer constant-velocity (CV) joint

A worn outer CV joint, often after its protective boot tears and lets grease out, typically clicks or pops during tight turns under power. That is when the joint works at its sharpest angle.

On a part-time or full-time four-wheel-drive truck, which component splits engine power between the front and rear drive axles?

Answer: Transfer case

The transfer case is mounted behind the transmission and sends power to the front and rear driveshafts. It often includes high and low range gearing.

A customer's tire sidewall reads P215/65R16 98H. What does the number 65 represent?

Answer: The aspect ratio: sidewall height as a percentage of tread width

In P-metric sizing, the number after the slash is the aspect ratio. Here the sidewall height is 65% of the 215 mm section width.

Which statement best describes regenerative braking on hybrid and electric vehicles?

Answer: The motor-generator works as a generator during deceleration, turning kinetic energy into electricity that recharges the high-voltage battery

During regenerative braking the traction motor acts as a generator. Its resistance slows the vehicle while it sends energy back to the high-voltage battery, and the friction brakes blend in as needed.