Are you looking to program a new key fob for your Porsche Cayenne without the hefty price tag of dealership services? Good news! It’s entirely possible to program your Porsche Cayenne Key Fob yourself using readily available tools and a bit of technical know-how. As your trusted auto repair experts at keyfobx.com, we’re here to guide you through each step of this process.
This guide will provide you with a detailed walkthrough on how to program a new key fob to your Porsche Cayenne, specifically models from the 955 and potentially 957 generations. While this method has been verified on a 2004 Cayenne S, it’s crucial to note that this procedure is not applicable to 958 models.
This process involves three main steps:
- Downloading the Kessy EEPROM
- Calculating the secret security PIN
- Programming new keys using VAG-COM
Once you complete steps 1 and 2, you only need to repeat step 3 to program additional key fobs in the future. Let’s dive into the tools you’ll need and then get started with the programming process.
Tools You’ll Need
To successfully program your Porsche Cayenne key fob, you’ll need the following tools:
- EEPROM Reader: Preferably with a 0.050″ SOIC clip-on adapter for easy connection to the EEPROM chip.
- VAG-COM Software and Cable: This diagnostic tool is essential for communicating with your Cayenne’s Kessy module and programming the new key fob.
Step 1: Downloading the Kessy EEPROM
This first step, downloading the Kessy EEPROM, might seem a bit technical, but with careful attention to detail, it’s manageable. It’s crucial to be aware of Electrostatic Discharge (ESD) safety. If you’re unfamiliar with ESD mitigation techniques, it’s best to seek assistance from someone with electronics experience.
-
Accessing the Kessy Module: Begin by removing the lower kick panel on the driver’s side. You’ll find a single Torx screw securing it. Once removed, disconnect the footwell light and unclip the OBDII port from the panel, setting the panel aside for easier access.
-
Locating the Kessy Module: The Kessy module is situated above the accelerator pedal, specifically the module closest to the passenger side in left-hand drive vehicles. It’s held in place by a plastic clip. Undo this clip and gently pull the Kessy module downwards.
-
Disconnecting the Kessy Module: Unplug the two electrical connectors attached to the Kessy module and remove it from the vehicle to bring to your workbench.
-
Opening the Kessy Module Case: On your workbench, use a small flat-bladed screwdriver to carefully pry open the clips securing the Kessy module case. Gently remove the case to expose the internal components.
-
Identifying the 93C86 EEPROM Chip: Locate the 93C86 EEPROM chip on the Kessy module’s circuit board. Pin 1 is typically located at the top left of the chip for orientation.
-
Reading the EEPROM: Using your EEPROM reader, carefully read the data from the 93C86 chip. The exact procedure will depend on your specific EEPROM programmer. If you don’t have a clip-on adapter, you may need to carefully wire in using test hook clips. Ensure your programmer is set to read in 8-bit mode if possible, as the 93C86 EEPROM in the Cayenne Kessy is configured for 8-bit reads. If your programmer defaults to 16-bit reads, you may need to lift pin 6 (which is pulled to ground) and perform a byte swap on the read data later.
-
Verifying and Saving the EEPROM Dump: Read the EEPROM multiple times, verifying that the checksum remains consistent between reads to ensure data integrity. Save the EEPROM file to your computer.
-
Inspecting the EEPROM Dump: Open the saved EEPROM file using your programmer software or a hex editor. Look for your Vehicle Identification Number (VIN) around address 0x120. If the VIN appears scrambled with every other character out of order, you’ll need to perform a byte swap of even and odd bytes to correct the data.
Important Backup: This EEPROM file serves as a crucial backup. In case anything goes wrong during the key programming process, you can reprogram the EEPROM with this file to restore the Kessy module to its original state.
Step 2: Calculating the Secret Security Pin
With the EEPROM dump successfully downloaded, the next step is to calculate the secret security PIN. This PIN is essential as it grants you the necessary security access to program new keys using VAG-COM.
-
Using an Online PIN Calculator Service: The most straightforward method to obtain your security PIN is using an online service like https://www.weboctopus.nl/immo-code-dump-to-pin.php. Upload your EEPROM file to the website and initiate the calculation. Crucially, select VW (Volkswagen) as the vehicle brand, not Porsche.
-
Purchasing Tokens: This service requires tokens for each calculation. You’ll need to purchase tokens; the smallest package is typically 5 tokens. While this involves a small cost, it’s significantly less expensive than dealer or locksmith programming fees.
-
Retrieving the Security PIN: Once the calculation is complete, the service will display your security PIN and also send it to the email associated with the token purchase. The PIN is always a number starting with ‘0’. If the service indicates it cannot calculate the PIN, double-check your EEPROM reading process and file.
This security PIN is unique to your Porsche Cayenne and remains constant unless the Kessy module is replaced.
Step 3: Programming New Keys Using VAG-COM
With the security PIN obtained, you’re now ready to program your new Porsche Cayenne key fobs using VAG-COM.
-
Reinstalling the Kessy Module: If you haven’t already, reinstall the Kessy module back into your Porsche Cayenne, reversing the removal process.
-
OBDII Connector Modification for VAG-COM: Cayenne’s OBDII connector K-line pin configuration differs from VW/Audi vehicles, for which VAG-COM cables are primarily designed. To address this, you have two options:
-
OBDII Extension/Y-Splitter (Recommended for Regular VAG-COM Use): Purchase an OBDII extension or Y-splitter cable and follow the wiring modification described in this Rennlist thread: https://rennlist.com/forums/cayenne-…ds-how-to.html. This permanent modification allows for seamless VAG-COM use on your Cayenne in the future.
-
Temporary Pin Swapping (For Key Programming Only): For a temporary solution solely for key programming, you can move pin 3 to pin 15 in the OBDII connector. Slide the purple locking clip on the connector to the side and remove it. Use a small pick to gently lift the locking tab for pin 3, pull the wire, and insert it into the pin 15 position. The connector is labeled for easy identification. After key programming, reverse this process to restore the original OBDII configuration.
-
-
Key Programming Procedure with VAG-COM: The key programming procedure is identical to that of the Volkswagen Touareg with Kessy. Follow the Ross-Tech Wiki guide here: http://wiki.ross-tech.com/wiki/index…atching_(Kessy. The brake pedal wake-up procedure mentioned in the guide is applicable to the Cayenne and typically takes about 10 seconds.
-
Understanding Measuring Blocks: Familiarize yourself with VAG-COM measuring blocks 022, 023, and 024, which provide real-time data about the key matching process. Block 24, not 23 as mentioned in some documentation, contains unlock times. Refer to Uwe’s forum post (https://forums.ross-tech.com/index.php?threads/17199/) for detailed information on these fields.
During the key programming, your Cayenne’s dashboard will display “System Learning.”
-
Key Insertion and Programming: You will need to insert a key blade into the ignition to program a key fob. If your new keys are not yet cut, you can use a cut blade from an existing key. Hold the new key fob very close to the blade as you insert it into the ignition for proper detection. Dummy keys (without transponders) will not work for programming.
-
Key Quality and Considerations: Be mindful of the quality of aftermarket key fobs. As personal experience indicates, some suppliers may have quality control issues. Also, ensure you are purchasing the correct type of key fob for your needs. Standard key fobs require physical insertion into the ignition, while “Entry and Drive” versions offer keyless entry and ignition.
Conclusion
Congratulations! You’ve successfully navigated the process of programming your Porsche Cayenne key fob yourself. By following these steps and utilizing readily available tools, you can save a significant amount of money compared to dealership or locksmith services and gain the convenience of programming additional keys whenever needed.
Now, armed with this knowledge, you can confidently manage your Porsche Cayenne key fobs and ensure you always have a spare, without breaking the bank. Happy programming from your experts at keyfobx.com!
