Are you tired of dealerships charging exorbitant prices to program a new key fob for your beloved 2005 Porsche Cayenne? The good news is, you don’t have to pay those hefty fees! With readily available tools and a bit of DIY spirit, you can program a new key fob yourself. This guide will walk you through the process of programming a 2005 Porsche Cayenne Key Fob, saving you time and money.
This method is confirmed to work on the 2004 Porsche Cayenne S and is highly likely to be applicable to all Porsche Cayenne 955 models, including the 2005 version. It might even work for 957 models, but it’s definitely not the procedure for newer 958 Cayennes.
Before you begin, gather the necessary tools:
- EEPROM Reader with SOIC Clip-on Adapter (0.050″): This tool is crucial for reading data from the Kessy module’s EEPROM chip without soldering.
- VAG-COM Software and Cable: A diagnostic tool essential for communicating with your Porsche’s computer system and programming the new key fob.
The process involves three main steps, with steps 1 and 2 only needing to be performed once. After completing these initial steps, you can add new keys anytime using just step 3.
Step 1: Downloading the Kessy EEPROM
This step requires some basic electronics knowledge and careful handling to avoid damaging sensitive components. If you’re not comfortable working with electronics, consider seeking help from someone with experience. Always practice ESD (Electrostatic Discharge) safety to protect electronic components.
First, locate the Kessy module. Start by removing the lower kick panel on the driver’s side. There’s usually a single Torx screw securing it. Once removed, disconnect the footwell light and unclip the OBDII port from the panel. Set the panel aside to provide better access.
The Kessy module is situated above the accelerator pedal, closer 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 down. Disconnect the two electrical connectors and take the Kessy module out of the vehicle.
Now, take the Kessy module to a clean, well-lit workbench. Carefully open the Kessy module casing using a small flat-blade screwdriver. Gently pry the clips holding the case together to avoid damage.
Identify the 93C86 EEPROM chip on the circuit board. This is the chip you need to read. Pin 1 is typically located at the top left of the chip.
Using your EEPROM reader and the SOIC clip-on adapter, carefully connect to the 93C86 EEPROM chip. Follow the instructions provided with your EEPROM programmer to read the chip’s data. Ensure you read the EEPROM multiple times and verify that the checksum remains consistent between readings. This ensures a reliable data dump. Save the EEPROM file to your computer.
Inspect the downloaded binary file using your EEPROM programmer software or a hex editor. You should see your Vehicle Identification Number (VIN) at address 0x120. If the VIN appears garbled with every other character out of order, you may need to perform a byte swap on the data. This might happen if your reader defaults to 16-bit reads instead of 8-bit, which is sometimes required for the 93C86 EEPROM.
This EEPROM file is also a valuable 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
Now that you have the EEPROM dump, the next step is to calculate the secret security pin. This pin is essential for gaining security access to the Kessy module and performing key programming functions using VAG-COM.
The recommended and user-friendly method to obtain this security pin is using an online service like https://www.weboctopus.nl/immo-code-dump-to-pin.php. Simply upload your EEPROM file to the website and select “VW” as the vehicle brand (not Porsche, as Cayenne systems are based on VW). The service will calculate the security pin for you.
This service requires tokens, and a minimum purchase is usually around 5 tokens for approximately 25 Euros. While this involves a small cost, it’s significantly cheaper and more convenient than dealership or locksmith alternatives. You might even be able to share or resell unused tokens if you purchase a pack.
After processing, you’ll receive your security pin, typically via email. The pin is usually a number starting with ‘0’. If the service cannot calculate the pin, double-check your EEPROM reading process and ensure the file is valid.
While other methods for calculating the security pin exist, this online service is generally considered the most reliable and least risky option for DIY users. Be cautious of standalone software that may require disabling antivirus software, as these can pose security risks. Specialized tools for pin calculation are available but are usually expensive and unnecessary for this purpose.
This security pin is unique to your Porsche Cayenne and remains constant unless the Kessy module is replaced. Keep it in a safe place as you will need it for key programming and other security-related functions.
Step 3: Programming New Keys Using VAG-COM
Now it’s time to program your new 2005 Porsche Cayenne key fob using VAG-COM. First, reassemble the Kessy module and reinstall it in your car, reversing the removal process from Step 1.
To use VAG-COM with your Porsche Cayenne’s Kessy module, you need to address the OBDII connector’s K-line pin differences compared to VW/Audi vehicles, for which VAG-COM cables are typically designed.
One solution is to use an OBDII extension or Y-splitter cable and follow the pin modification procedure detailed in forums dedicated to Porsche Cayenne and VAG-COM. This allows for permanent VAG-COM compatibility with your Cayenne.
Alternatively, for a simpler, temporary solution, you can temporarily relocate pin 3 to pin 15 in your Cayenne’s OBDII connector. To do this, slide the purple locking clip on the OBDII connector to the side to unlock it. Use a small pick or similar tool to gently lift the locking tab on the pin 3 wire. Carefully pull the wire from pin 3 and insert it into the pin 15 position. The connector is labeled on the back, making pin identification straightforward. After key programming, simply reverse this process to restore the OBDII connector to its original configuration.
The basic key programming procedure is similar to the one for Volkswagen Touareg models with Kessy, as outlined in the Ross-Tech Wiki (http://wiki.ross-tech.com/wiki/index.php/Immobilizer_III_KeyMatching(Kessy)). The brake pedal wake-up procedure described in the Ross-Tech article is indeed applicable to the Porsche Cayenne.
During the key programming process with VAG-COM, pay attention to the measuring blocks, particularly block 24 (unlock times), and familiarize yourself with the values before starting. Ross-Tech forums (https://forums.ross-tech.com/index.php?threads/17199/) provide further details on these fields:
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022.1 Start procedure permitted: Indicates if the car can be started. “Yes” means the key is matched correctly; “No” indicates a problem.
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022.2 ECM responding: Confirms communication with the Engine Control Module (ECU). “Yes” is expected; “No” indicates a communication issue.
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022.3 Key condition OK: Verifies if a legitimate transponder code is being read from the key. “Yes” is needed for successful key matching.
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022.4 Number of adapted keys: Shows the number of keys currently programmed. A maximum of 8 keys can be adapted.
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023.1 Authentication OK: Indicates successful authentication.
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023.2 Lockbits,set: Lock bit status.
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023.3 Key ID authorized: Confirms key authorization.
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023.4 Immobilizer,status: Immobilizer system status (refer to VAG-COM label files for specific decoding).
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Lock Times (Block 024):
- 024.1 Immobilizer,minutes: Immobilizer lock time in minutes.
- 024.2 A-CAN,minutes: A-CAN lock time in minutes.
- 024.3 Scan protection,minutes (key): Scan protection time for the key.
- 024.4 After adaptation,minutes: Time after adaptation in minutes.
During key programming, the instrument cluster may display “System Learning.” Follow the VAG-COM instructions and Ross-Tech guide carefully to complete the key matching process.
For key programming, you’ll need to insert a key blade into the ignition. If your new key fob doesn’t have a cut blade yet, you can temporarily use a blade from another key. Hold the 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.
When purchasing new key fobs, be aware of potential quality issues and ensure you are getting the correct type for your needs. Some aftermarket keys may have quality control problems or may not support features like Entry and Drive if your Cayenne is equipped with it.
Conclusion
Programming a 2005 Porsche Cayenne key fob yourself is entirely achievable with the right tools and guidance. By following these steps, you can bypass expensive dealership services and gain the satisfaction of DIY car maintenance. The initial setup involving EEPROM download and PIN calculation might seem a bit technical, but once completed, adding new keys becomes a straightforward process using VAG-COM. Don’t let a lost or broken key fob stress you out – take control and program your new 2005 Porsche Cayenne key fob yourself today!
