How to Get and Use Security Password of Volkswagen Cars
If you don’t know the security password of Volkswagen cars or you have lost the cipher card, you can get the password according to steps following:
Link Launch X431; Turn the ignition switch on; Choose an anti-theft system; Press the “Confirm” button twice. After about 5 seconds, it will show information about the ECU on the screen. At this time, repairing station may check out the 14-digit number of the anti-theft control unit using Launch X431. Then it will telex to after-sales service system of VW which will get the password (A 7-digit number includes the country code, the dealer code and the service station code.) telexed to the repairing station to create the key.
After you changing the anti-theft control unit, the repairing station should also check out the 14-digit number and telex it to the after-sales service system which will telex the password checked out by itself to the repairing station to create the key.
Instructions: there are a 14-digit number and a 4-digit password sticking on the anti-theft control unit used by cars. This is a blackened cipher card hanging on the key ring of the new car or there is a blackened password strip on the left of the passenger seats’ toolbox. If so, scrape off the Blackened layer you can see a 4-digit password.
If it is the second-generation anti-theft system, you will get a 4-digit password.
If it is the third-generation one, you will get a 4-digit or a 7-digit password.
For the generation of the password, it is a database related to the 14-digits PIN of the anti-theft device. And the password is alway a 4-digit number(Hexadecimal one). Through querying the database by entering the 14-digit PIN of the anti-theft device you can get the 4-digit password and then you will get the 7-digit one calculated by a formula with Dealer code, Service Station Code and Query Date. This is just the key that after you getting the 4-digit password you can the 7-digit one through another algorithm with information that you offered. Which is a process of coding.
You have to settle down the query date after you get the 7-digit password for that X431 requires these two all as well as the dealer code and service station code. The X431 will get a 5-digit password(Decimal number) then by decoding the 7-digit password and information above. This is a inverse process for coding-process of encoding. In other words, whether the input is 7-digit or 5-digit password (Decimal) the final code transferring on the Data Bus is the 4-digit password (Hexadecimal). And what stored inside the immobilizer control unit is a 4-digit password (Hexadecimal).
If the password you input matches the one stored inside the immobilizer control unit through conversion,calculation,encryption,decryption and transferred to it you are authorized and you can now match the keys. Conversely, you have to wait until you can input another password.
Before logging in by inputting a 7-digit password you should choose “System Log in”-“7-dogit password” after into the system to input the 7-digit PIN number, service station code, dealer code and query date to get a 5-digit password(Decimal) which is the original password.
Identifying the second-generation or the third-generation anti-theft system of Volkswagen carsMethod to differ the second-generation and the third-generation anti-theft system of Volkswagen cars is like bellow: Into the engine system; Read the information of ECU’s version; Settle down the computer model; Do what above again. If these two computer model are the same it is the second-generation anti-theft system, or it is the third-generation one.
1. The second-generation anti-theft system
Instructions on car keys’and matching keys’ using: Only using the recognized key which matches with the immobilizer control unit installed in the car, the engine can be started.
When matching car keys, all the keys are always need to match all the keys to the immobilizer control unit simultaneously. If you just need to match the car keys again or match one more key you should also do this.
If you lose one of the legal keys you have to match all the other legal keys again by X431 for the safety reason. Thus the lost key will become illegal and cannot stat the engine.
These are some methods to identify the second-generation anti-theft system for different situations bellow:
(1) Replace the matching program of the control unit
After replacing the control unit of the engine it have to match with the immobilizer control unit again.
Necessary option: one of the legal keys.
Steps:
① Link X431
② Turn on the ignition switch
③ Select the anti-theft system and then select “Channel Adjustment match” function and press the “Enter” key at last
④ Input channel number 00 and press the “Enter” key
⑤ Clear the learning value
Instructions: As the ignition switch is on at the moment, the random code of the engine’s control unit will be stored by the immobilizer control unit.
(2) Replace the matching program of the immobilizer control unit
① Replace the immobilizer control unit by a new one:
The random code of the engine’s control unit will be read and stored automatically by the immobilizer control unit and you need match all the keys one more time.
② Replace the immobilizer control unit by one detached from other cars:
You need match the engine’s control unit with the immobilizer control unit once more and match all the keys one more time.
2. The third-generation anti-theft system
Passat B5 1.8T 2.8, new Polaris, Polo and AUDI A6 produced by FAW from the 23th week of 2000 equipped with the third-generation anti-theft system. In the third-generation anti-theft system combined to the meter combination. To test this system you have to enter it through dashboard system. You can enter it through the anti-theft system but you will get a series of useless data.