CAL Automotive Door and Trunk Lock Systems 2

Question 1

What is the primary structural difference between a trunk lock cylinder and a door lock cylinder in most vehicles?

Accepted Answer

Trunk lock cylinders typically have fewer wafer or tumbler positions

Answer

Trunk lock cylinders typically have fewer wafer positions (often 4–5) than door lock cylinders (often 6–8), reflecting a lower security priority for trunk access in most vehicle designs.

Question 2

A customer reports that power door locks work from the interior switch but not from the key fob. What is the most likely cause?

Accepted Answer

Dead or weak key fob battery

Answer

Since the interior switch bypasses the RF signal path entirely and still works, a dead or weak key fob battery is the most common cause of remote-only failure.

Question 3

Which of the following best describes a 'passive entry' system on modern vehicles?

Accepted Answer

The vehicle unlocks automatically when the authorized fob is in proximity without pressing any button

Answer

Passive entry systems use low-frequency signals to detect an authorized fob within range and automatically unlock the door when the handle is touched, requiring no button press from the driver.

Question 4

When servicing a trunk latch that will not release via the interior handle, what component should be checked first?

Accepted Answer

The release cable or actuator rod for binding or disconnection

Answer

A binding, kinked, or disconnected release cable or actuator rod is the most common mechanical cause of trunk latch failure and should be inspected before checking electronic components.

Question 5

What does the term 'slam latch' refer to in automotive trunk systems?

Accepted Answer

A latch that engages automatically when the trunk lid is pressed closed

Answer

A slam latch (auto-latch) uses spring tension to engage automatically when the trunk lid is closed, eliminating the need to manually turn a key to secure it.

(CAL) Certified Automotive Locksmith Practice Test

(CAL) Certified Automotive Locksmith Practice Test

CAL Automotive Door and Trunk Lock Systems 2