Audi A6L / Q7 steering lock module J518 fault result below troubles:
1.When use key to start you car,it is OK to switch,but the dashboard light off and can not unlock the steering lock,engine will not start.
Use VAG diagnostic tools to read trouble code,sometime after clear the trouble code,you can use key to start engine again,but sometime can’t.
There are main reasons result in Steering Lock Module J518 trouble:
1. Interior CPU fault
2.Interior relay fault
Here comes the corresponding solutions.
The most effective way to solve CPU Damage is replacement.You can buy new one to replace old.But you should pay attention to the data in old CPU.Before replacement,you need to use programmer to read and save the data in old CPU,include flash data and eeprom data.Different programmer have different wire connection style.
CPU Model Num: Begin with MC9S12 and end in(0L01Y/1L59W/3L40K)
Then welding it back on J518,and write the old CPU data in the new CPU.After,assemble it back to car,it ok! No need match the key!
Note:You should have a skillful welding.
Reply fault is easier than the CPU fault.Just replace new one.
At the end of this article,car repair advise you to replace both,it will save you more time.