We’ve all heard stories about cars being stolen with things like “shaved keys” and we are forced to ask ourselves what steps are being taken to protect our cars from this type of attack?
PREVENTING AUTO THEFT WITH CHIP KEYS
Starting in the mid 90’s, automotive manufacturers and insurance companies wanted to make it harder to steal cars so a simple transponder and receiver idea was employed.
The transponder chip is embedded into the head of the key and the receiver antennae ring surrounds the ignition housing. The car sees the transponder as it gets in range of the antenna ring. It asks for the unique ID number of the transponder and the transponder returns the information to the car. If the chip ID is recognized as valid the car is allowed to start. If not, the car is told to go into a security mode which prevents the car from starting.
REPLACING KEYS FOR CARS WITHOUT A PROGRAMMING METHOD
For today I want to discuss the cars that don’t specifically have a “back door” for programming when all keys are lost.
If a car doesn’t have a programming method, the standard procedure is to remove the module that the immobilizer information is stored in and replace the module with a new one. For example, many Toyota and Lexus modules made before 2006 had no means to add a key to the ECU (Engine Control Unit) or immobilizer box without a working master key. An ECU and 2 new keys can cost as much as $2500.00 to replace. Other examples are found in Honda, Acura, Subaru, Isuzu, SAAB, Porsche, Fiat, VW and more.
We then need to either replace the data with a virgin file (so the car thinks it’s a brand new module), interpret the EEPROM data to produce an existing transponder chip, or add values to the ROM for our transponder.
Reading the chip in circuit is always the preferred method. However, if you are using a programmer that doesn’t have variable supply voltage you may inadvertently power up other components in the immobilizer and cause interference with gathering the EEPROM data. In situations like this, you either need to lower the supply voltage, block the power on one of the data tracks, or simply short the oscillator out to prevent the microprocessor for operating. If this is not an option, you must remove the chip and read it out of circuit.
As our EEPROM reading ability increases, it no longer requires the customer to purchase and replace the affected module. Instead, we can prepare transponder chips and get vehicles back on the road faster, without towing.