CPL Automotive Lock & Transponder Systems 3 — Questions and Answers
Question 1: What frequency do most North American remote keyless entry (RKE) fobs transmit on?
- 125 kHz
- 315 MHz (Correct answer)
- 433.92 MHz
- 2.4 GHz
Correct answer: 315 MHz
Most North American RKE systems use 315 MHz, while European systems typically use 433.92 MHz.
Question 2: What is the purpose of the antenna ring around the ignition cylinder in a transponder system?
- It amplifies the key's radio signal to the ECU
- It energizes the transponder chip via inductive coupling and reads its response (Correct answer)
- It detects key insertion depth
- It provides power to the immobilizer relay
Correct answer: It energizes the transponder chip via inductive coupling and reads its response
The antenna ring uses inductive coupling to power the passive transponder chip and receive its identification signal when the key is inserted.
Question 3: Which programming method requires the locksmith to enter a specific sequence of actions using the existing working key?
- OBD-II programming
- On-board programming (Correct answer)
- Dealer-level programming
- EEPROM programming
Correct answer: On-board programming
On-board programming (also called self-programming) uses a sequence of key turns, door operations, or button presses with an existing working key to add new keys.
Question 4: A technician needs to program a key for a vehicle with a crypto-secured transponder system (like Megamos Crypto). What is required?
- Only a cloner tool
- On-board programming sequence only
- Advanced programming device with vehicle-specific software and possibly PIN/CS code (Correct answer)
- Resistor pellet matching
Correct answer: Advanced programming device with vehicle-specific software and possibly PIN/CS code
Crypto-secured transponder systems require specialized programming equipment, often with vehicle-specific software, and may require a PIN or CS (crypto secret) code.
Question 5: What is a 'dead lock' feature in automotive door systems?
- A lock that cannot be opened from inside or outside when engaged (Correct answer)
- A lock that fails permanently after tampering
- A lock requiring two key turns to open
- A backup mechanical lock when electronics fail
Correct answer: A lock that cannot be opened from inside or outside when engaged
A deadlock (or double-lock) prevents the door from being opened from inside even if the interior handle is pulled, providing extra security against break-in.
Question 6: When making an automotive key by code, what does the term 'cut progression' refer to?
- The order in which key cuts are made on the machine
- The incremental depth steps available for each key position (Correct answer)
- The sequence of positions from bow to tip
- The speed at which the cutting wheel moves
Correct answer: The incremental depth steps available for each key position
Cut progression defines the allowable depth values (increments) at each position; valid bittings must follow these progressions to prevent key binding.
Question 7: Which component stores the secret cryptographic key in a vehicle's immobilizer ECU?
- The antenna ring coil
- The transponder chip's EEPROM
- The vehicle's BCM or immobilizer module EEPROM (Correct answer)
- The OBD-II port interface
Correct answer: The vehicle's BCM or immobilizer module EEPROM
The vehicle's BCM or dedicated immobilizer module contains an EEPROM that stores the secret crypto keys and authorized transponder IDs.
CPL Automotive Lock & Transponder Systems 3
What frequency do most North American remote keyless entry (RKE) fobs transmit on?