brett968

Yes, it is possible to program/match new key fobs to your Cayenne without going to the dealer or a locksmith and using readily available tools! In fact, it's actually quite simple (IMO)! These are the basic steps:

1) Download the Kessy EEPROM
2) Calculate the secret security pin (required for next step)
3) Program new keys using VAG-COM

Steps 1 and 2 only need to be performed once. After this, new keys can be added at any time using step 3.

Supported vehicles:

I have verified that this works on my 2004 Cayenne S. I have not tested this on any other vehicle. I suspect it works for all 955s and it may work for 957s as well. It is definitely not the correct procedure for 958s.

Tools/equipment needed:

- an EEPROM reader, prefererably with a 0.050" SOIC clip-on adapter
- VAG-COM software and cable

Step 1 - Download the Kessy EEPROM

This is the only step that might be tricky for some people. Any electronics geek should have no problem with this though. You should be familiar with basic ESD mitigation handling techniques. If you don't understand what I just wrote then you should find an electronics geek to help you.

First, remove the lower kick panel on the driver's side. There is only the single torx screw to remove. Unplug the footwell light and unclip the OBDII port from the panel. Put the panel to the side. (Optionally you can leave it in but it will just get in the way.)

The Kessy module is above the accelerator pedal. It is the module closest to the passenger's side (left-hand drive cars). There is a single plastic clip holding it in place. Undo the clip and pull the Kessy module down. Unplug the two electrical connectors and remove the Kessy module from the vehicle.



Take the Kessy module to the workbench where you will be working on it. Using a small flat-bladed screwdriver, pry gently on the clips holding the case on and remove the case.



The location of the 93C86 EEPROM that you need to read is shown below. Pin 1 is top left.



Use your EEPROM reader to read out the chip. The exact procedure depends on your EEPROM programmer. I used a programmer that I had on hand but it was not ideal for this task. There are cheap EEPROM programmers all over eBay. I will let others explore the options and determine which is best to use here.

I did not have a clip on adapter for my reader so I had to wire in using test hook clips. The other problem I had was that my programmer defaulted to 16-bit reads and there was no way to select 8-bit reads. The 93C86 EEPROM can be configured for 8-bit or 16-bit reads. This is determined by the logic level on pin 6. On the Kessy, this pin is pulled to ground. To get my programmer to work properly I had to lift this pin. I also had to perform a byte swap afterwards on the read-in data due to the 16-bit read. Again, my setup wasn't ideal. I know there are cheap programmers that have clip-on adapters and support 8-bit reads on this chip. This would make this step much easier for most people.



Read the EEPROM a few times and verify that the checksum isn't changing between reads. Save the EEPROM file to disk. Use your EEPROM programmer software or an external tool to inspect the binary download. It should look something like this. The VIN should be at address 0x120. If you see something that looks like your VIN but every other character is out of order then you need to swap all the even/odd bytes.



Note that this EEPROM file also serves as a backup in case something goes screwy during the key programming process. I am fairly certain that you could reprogram the EEPROM with this file and recover the original state of the Kessy.

Step 2 - Calculate the secret security pin

Now that you have the EEPROM dump, you need to calculate the secret security pin. This pin is what gives you security access to perform the key programming functions through VAG-COM. The best way that I know of to get the security pin is to use this service: https://www.weboctopus.nl/immo-code-dump-to-pin.php . You simply upload your file and press calculate. Be sure to select VW as the vehicle brand (not Porsche). You will need to buy tokens to use this and the smallest increment is 5 tokens at a cost of 25 Euros. If you buy a five pack, you can use the one token for your car and sell/give the other 4 tokens to friends.



You (or the original token purchaser) will also receive an email with your security pin. If the online tools says it cannot calculate the pin then you probably screwed up the EEPROM read. The pin is the first number and it will always begin with a '0'.



There are other options to calculating the security pin but this was the least sketchy option I could find. There are some stand-alone apps out there for this but the one I saw required that you disable your antivirus software. Umm, no thanks. There are also $$$ tools that will calculate the security pin but buying one of these tools would totally defeat the purpose. For $6, the service I described is a no-brainer.

Now that you have your pin, you can program keys and do other tasks that require security access. This pin is unique to your car and never changes (unless you replace the Kessy).

Step 3 - Program new keys using VAG-COM

If you haven't done so already, put the Kessy back in to the vehicle. Installation is reverse of the removal process.

To use VAG-COM with the Kessy module, you need to do something about the OBDII connector K-line pins on the Cayenne being in a different location than the VW/Audi's that the VAG-COM cable was intended for. One way to do this is to buy an OBDII extension or y-splitter and follow the procedure discussed in this thread: https://rennlist.com/forums/cayenne-...ds-how-to.html . This option is nice in that it allows you to use VAG-COM on the Cayenne whenever you need to. If you don't care about this, then there is an easier option. Simply temporarily move pin 3 from the connector to pin 15. To do this, slide the purple locking clip to the side and remove it. Use a small pick to lift up the pin locking tab pull the wire from pin 3 and place it into the pin 15 position. The back of the connector is labelled, making this really easy. When you are done programming your keys, simply reverse the process.




The basic procedure for programming the keys is exactly the same as the one for the Touareg outlined here: http://wiki.ross-tech.com/wiki/index...atching_(Kessy) Note that the brake pedal wake-up procedure described is in fact applicable to the Cayenne (from what I saw it wakes up in about 10 seconds).

Note that the unlock times are actually in block 24, not block 23 as the page says. You may want to familiarize yourself with these fields a bit before you start the key programming process. Try the different keys and see how the values change. Uwe posted more information on these fields on his forums (from https://forums.ross-tech.com/index.php?threads/17199/) :

022.1 Start procedure permitted | Yes = car can be driven No = key is not or matched or incorrectly matched or the Engine Control Module is incorrectly adapted or malfunctioning
022.2 ECM responding | Yes = ECU communications OK (whether ECU is matched or not) No = not possible to match the Immo to the ECU at this time.
022.3 Key condition OK | Yes = a legitimate transponder code could be read (authorized or not) No = it will not be possible to match this particular key
022.4 Number of adapted keys, A maximum of 8 adapted keys is permitted.

023.1 Authentication OK Possible display: Yes or No
023.2 Lockbits,set Possible display: Yes or No
023.3 Key ID authorized Possible display: Yes or No
023.4 Immobilizer,status,Please see the label file for decoding information.

Lock Times:
024.1 Immobilizer,minutes,
024.2 A-CAN,minutes
024.3 Scan protection,minutes (key)
024.4 After adaptation,minutes

While you are programming the keys, the dash will display something along the lines of "System Learning". I was busy and didn't get a picture of this. I don't have a whole lot else to say about the key matching procedure as it is pretty much as described on the VAG-COM instructional page I linked to above. It went very smoothly for me but YMMV.

Note that you will need to be able to put a key blade in the ignition to program a key. If you haven't cut the keys yet but have a cut blade available from another key, then you can remove the blade assembly and use the same blade for all the keys you want to program. The procedure for this is to hold the key fob very close to the blade as you insert it into the ignition. It must be close or it will not be detected properly. Also, I'm pretty sure I tried the dummy key and this didn't work.

A note on keys. I bought 3 keys from here: https://www.remotesremotes.com/produ...ProductDetails . One of the keys had a broken unlock button and a broken panic button. The second key was assembled incorrectly and had a very large gap--large enough to potentially allow the blade to fall off. The third key had no obvious physical defect. So 1 for 3. Pretty terrible quality control. Also, be aware that these keys are NOT the entry and drive version of the keys. Unfortunately, I learned this the hard way. I programmed the 1 new key (along with my original key) successfully but the new key must be physically inserted into the ignition. I have located the entry and drive version of the keys elsewhere and will be trying them soon. I'll report back with my findings.

So, using only tools that I already had on hand, the total cost to obtain the ability to program keys was $6 (assuming I can sell my 4 unused tokens for $6/each) and I can add keys whenever I want!

Now you don't have any excuse for not having a spare key(s)! Have fun programming!

oldskewel

Wow, that does look easier than I thought it would be. I probably won't even need to dust off my scanning electron microscope (LOL, who uses those any more) to attach the micro probes to the EEPROM leads there.

More general question on the KESSY ... is it true (I believe it is) that there are different levels of that, as an option? Such as where the car will simply detect the presence of the key fob, rather than requiring a button press? I know that my 2004 S requires either the mechanical key, or the fob button press to unlock. And that when I opened up one of the door panels to replace the door lock actuator, I learned about the different functionality of KESSY (and that my car had the lower level, perhaps meaning it does not have "KESSY"). Still wondering - do all 2004 S have KESSY, and are there really different levels ???

brett968

All the cars have a Kessy module but the entry and drive feature is optional.

TomF

Wow! Great writeup. Thanks for doing this.

Yep. Entryand Drive is the one of the few options my 2009 CTTS doesn't have. The Entry and Drive has different door handles, wiring looms and a whole bunch of antennas. It would be very hard to retrofit even with a complete system from a donor car.

Dave Waldo

Thanks.

This security pin, is it just for the key or might this unlock other features on the cars ?

brett968

The security pin is also needed when swapping out the engine computer. I'm not sure if it's used for much more than that.