CAL Ignition System Servicing 3 — Questions and Answers
Question 1: What is the purpose of a 'plug follower' when servicing an ignition cylinder?
- To push the key plug out of the housing while retaining the springs and pins (Correct answer)
- To read the key cuts without a key present
- To bypass the immobilizer system temporarily
- To test the ignition switch electrical output
Correct answer: To push the key plug out of the housing while retaining the springs and pins
A plug follower is inserted behind the key plug as it is removed to keep springs and pins loaded in the shell, preventing them from scattering.
Question 2: When decoding an ignition cylinder by feel using a pick, the locksmith is determining which characteristic of the wafers or pins?
- Their material composition
- Their height or depth setting within the cylinder (Correct answer)
- Their spring tension
- Their orientation (left or right)
Correct answer: Their height or depth setting within the cylinder
Decoding by feel involves sensing where each tumbler sets, revealing the depth value at each cut position, which translates directly to the key's bitting code.
Question 3: A vehicle owner reports that the ignition key turns but the engine does not crank. Which component should the locksmith suspect FIRST?
- The ignition cylinder mechanical linkage to the ignition switch (Correct answer)
- The battery terminals
- The starter motor brushes
- The ECM programming
Correct answer: The ignition cylinder mechanical linkage to the ignition switch
If the key turns freely but no electrical action occurs, the mechanical-to-electrical linkage between the ignition cylinder and the switch behind it may be broken or disconnected.
Question 4: Which ignition key type uses a round, hollow shaft and is associated with motorcycles, desks, and some older vehicles?
- Laser cut key
- Tubular key (Correct answer)
- Valet key
- Sidewinder key
Correct answer: Tubular key
Tubular (barrel) keys have a hollow cylindrical tip with cuts around the circumference and operate tubular pin tumbler locks found on motorcycles and other applications.
Question 5: When a high-security ignition lock uses a sidebar mechanism, what additional element must align for the cylinder to rotate?
- A secondary spring plate inside the key head
- Gates in the sidebar pins that must line up with the sidebar (Correct answer)
- A magnetic strip on the key blade
- An RFID chip frequency match
Correct answer: Gates in the sidebar pins that must line up with the sidebar
Sidebar locks require both standard pins/wafers to set AND sidebar pins to align their gates with the sidebar, making picking significantly harder.
Question 6: After installing a replacement ignition cylinder on a 2010s Chrysler vehicle, what additional step is commonly required?
- Resetting the tire pressure monitoring system
- Programming or initializing the new cylinder to the vehicle's PATS or immobilizer system (Correct answer)
- Replacing the steering column airbag sensor
- Re-calibrating the cruise control module
Correct answer: Programming or initializing the new cylinder to the vehicle's PATS or immobilizer system
Modern Chrysler vehicles use transponder-based immobilizers that must recognize the new cylinder's associated key chip, requiring programming with appropriate equipment.
Question 7: What is the correct procedure when an ignition cylinder must be drilled as a last resort?
- Drill through the entire cylinder to destroy all tumblers
- Drill at the shear line to separate the plug from the shell while minimizing damage (Correct answer)
- Drill from the rear of the cylinder toward the front
- Use the largest drill bit available to ensure complete removal
Correct answer: Drill at the shear line to separate the plug from the shell while minimizing damage
Controlled drilling at the shear line separates plug from shell, allowing rotation without destroying more of the housing than necessary and enabling proper replacement.
CAL Ignition System Servicing 3
What is the purpose of a 'plug follower' when servicing an ignition cylinder?