I just wrote this for a passat CC customer:
Let me cover a few common questions.
Can the dealer see APR flashed my car?
No. All flash counters and original ECU information is retained. It will appear identical on all scantools as the way it was before flashing with APR software.
Can the dealer drive my car, feel the difference, and log the car to see the difference, thus identifying I'm chipped?
Yes. But we have a way to protect against this. If you purchase 'Stock Mode' you get an identical copy of your stock calibration. If you put the car in stock mode, they will not be able to tell a difference since the stock mode is the same exact stock calibration that came with your car.
Is stock mode really 'stock' or is it APR's version of stock?
It is stock. APR's program switching routines allows us to reflash the ECU each time you switch programs. Everything is internal and not though external devices. We simply have a copy of the stock program in the ECU.
Can't the dealer just switch from stock mode back to APR chipped mode if they know how to switch programs? Woln't they see the flashing lights APR uses for program switching and tell I'm chipped?
Yes. But we have a way to protect against this too! If you purchase 'Security Lockout' you can lock your car in stock mode. When locked, you must enter a code into the car to change programs. There's no indication of flashing lights or any ability to switch programs until this code is entered. This code is chosen by you. It's 4 digits long, much like an ATM pin number.
Can't the dealer just check boost log history in the ECU?
No. The ECU does not store boost logs.
But I've seen fault codes that list ambient pressure!
Ambient pressure is not boost pressure. Ambient pressure is the pressure outside the vehicle. The ambient pressure sensor is a small sensor physically located in the cars computer chip board.
I'm smart. I know you cant just add code and expect a file size to stay the same. If the dealer looks at the factory ECU file size and compares it to your file, it will be different
First off, the dealer cant do this but even if they could it wouldn't matter. ECU files sizes are fixed in length. Think of the file size as a piece of paper. If you write on only half of a piece of paper and you write on an entire piece of paper the size of the paper is still the same. That's how the ECU files work. You're given a file that's about 2 megs. If you don't use up some of the area on that file, it's still two megs. We fill up the unused area.
Oh, well then cant the dealership just compare the two files and see one looks different than the other?
Nope! Each file is encrypted, even when it's completely stock. It's a bunch of jumbled garbage. It's calculated before flashing to the car. No two files are identical and they require a super computer array to decrypt the files and recalculate all checksums and RAS encryption keys before flashing/decrypting/encrypting etc.
Can't the dealer just ask for the encryption keys?
No. Bosch does not give out that information nor do they check ECU's for dealerships.
