VVDI Prog Read and Write Problematic BCM of Porsche

 How to successfully read and write the problematic front BCM of many Porsche models.

Recently a customer of ours lost all his keys on his 2012 Porsche Cayenne S. We have several programmers on hand but at a glance it seemed that Autel would be able to program keys without a fuss. More research should have been done but what I’ve realized is that Autel IM608 and its complementary programmer XP400Pro aren’t the best at it.

While I managed to backup the D-flash, Autel wiped off my P-flash. Some say that XP400 doesn’t do that, I’ll never know because I won’t use Autel in the future with this BCM.
In hindsight, it could have still worked had I not backed up the P-flash. Normally you only need the D-flash file and once you copy it then you can do your keys via OBD with the IM608.

So Autel IM608 might do it but I have more confidence in VVDI-prog and VVDI2 from Xhorse. The steps with VVDI are pretty straightforward. I didn’t use the solderless adapter, I soldered the wires. Below are the steps:

Once you desolder the zero ohm resistor, the diode and cut the trace on the pcb between the quartz and MCU, connect your wires and select Read/Write/Unlock. You must select the option without adapter. Read your D-flash and save it. You’ll want to verify the file, so hit verify (at the top menu), if all ok, you can put the BCM together.

You will connect your VVDI2 key programmer via USB to your computer. Select “Porsche” and load your file that you saved previously. Check and select an empty key slot, usually two keys are programmed, you select emply slot/key3. Now put your key in the programmer’s slot and kit “Make dealer key”. Save that file in your computer, name it “dealer key3” or something like that; you’ll need that to learn the key (s).

You have to options now, you can learn the key via the programmer or via OBD2. I did it via OBD2.

Connect your BCM to your car and VVDI2 key programmer via OBD2 connector. Your laptop is connected with the programmer via the USB cable. Hit the brake pedal a few times and push the hazard lights switch on to wake up the CAN network.

IMPORTANT: if you turn your hazard lights on but you can’t see your two blinking arrows in the instrument cluster your BCM isn’t communicating with the vehicle. Most likely your P-flash is corrupt or BCM damaged.

In the programmer at the top hit “Learn key”. It will ask you to load your file, now select “dealer key3” that you just saved. Hit “learn key” again, at the bottom of the screen it will say “learning key”, after a few seconds it will prompt you to insert key 1 (your key to be programmed) in the ignition and turn ignition on. If successful, the lights on the dash will turn on.

If you have a second key, remove the programmed key and insert your second key. Same process, turn ignition to on position (lights on dash won’t turn on at this stage), once key is programmed the lights on the dash will turn on. Wait for the programmer to finish learning your key. Once the keys are learned, check it the car starts and if remote lock/unlock functions work.

If you cannot read your D-flash, because it says chip is crypted, you’ll have to unlock the chip. My D-flash was already read by Autel so I didn’t have to do it but I had to unlock the chip in order to write the P-flash that I found online. I had to use “force unlock” with the VVDI-prog.

If you need to unlock your MCU, select “Force unlock”, the option without the solderless adapter if you’re soldering the wires. If you use the solderless adapter make sure your alignment is dead on. Once it unlocks your chip, it will say decrypt 7D location. That’s the memory location that you have to use to lock the chip again once your done reading/writing.

Hit “Read ID” with top menu button. If it reads numbers and letters, your chip is unlocked and you can proceed reading/writing. If it reads FEEE, your chip is locked. If you want to read and make a copy of your D-flash, make sure your D-flash button is pressed not the P-flash. The D-flash should be pressed by default. Verify your file and save the D-flash. Autel damaged my P-flash when I tried to read it, so I wouldn’t read the P-flash since you only need the D-flash to program keys. If you clone your BCM then both P and D flash files are needed.

Now that you have a good copy of your D-flash file, hit “Lock” at the top menu. It will ask what memory location, enter 7D. Once locked, read ID, if it reads “FEEE” that means it’s locked. From here you can proceed and learn your keys with VVDI2.