Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recommended Posts

So on the way home yesterday, everything drove fine. Key fob in my pocket, door handle unlocks no problem, "dummy" entry and drive works no problem to start the car.

Drive home and go to turn the dummy key to the left for 2 seconds (normal) and it won't complete the "shutdown" (move column in and what not). Go to turn the dummy key back to START and it says NO KEY FOUND.

try to lock and unlock with the handles, nothing. The key fob BUTTONS work to lock and unlock....but the proximity sensors on the handles do not.

To start the car now i can no longer use the entry and drive feature.....it requires the use of the key in the fob.

Three questions to start the discussion:

1. Why does the fob key work to start the car, and why do the buttons works, but nothing else?

2. Considering EVERYTHING no longer works, is it safe to assume the Kessy module?

3. Is there a fuse location i could check to see maybe the Kessy is not powered?

I don't have any sort of diagnostics, which i know will make it difficult to diagnose. But last resort will be to bring to and Indy shop with the porsche programmer.

Thanks

Share this post


Link to post
Share on other sites
    You can remove these ads by becoming a Contributing Member.

loren, Do you have a wiring diagram of the two plugs on the module? it would be easy to diagnose if i had the diagram to scope the various inputs and outputs of the module.

How does the ignition portion work? When i use the key fob key, is it just using a mechanical lock tumbler to allow the ignition to work? Or is it still using a sensor to read the key that is being inserted into the tumbler.

I find it interesting that everything stopped working at once.....meaning it must be a common issue i the Kessy Module.

Share this post


Link to post
Share on other sites

To my knowledge, there are no published diagnostics for this module other than through the Durametric system or the PIWIS, so I am not sure you will get anywhere testing inputs and outputs as there are alot of CAN bus communications involved...........

On the Kessy system, you have 3 interior antennas, and 6 exterior antennas. All four door handles have an antenna in them, and the rear bumper has two.

Communication path for Keyless Entry - Opening VehicleTouching the door handle (proximity sensor) leads to sending a key query signal in the area of the vehcleProximity sensor in door handle detects a hand touching it and sends a wake-up signal on the line between the door handle and the Kessy/Immobilzer control unit. Kessy activates a search for a valid key in the area via the integrated antenna in the door handle. The carrier signal is a 125 KHz field that is brodcast by the door handle antenna. The search signal is modulated on this signal. The search takes place only on the side of the vehicle that the wake-up-signal was triggerd on.The key transmitter answers the query from the Kessy using the alarm radio frequencythe key receives the 125KHz transmitted, evaluates the signal and sends a corresponding answer using the alarm remote frequency (315 MHz, USA market) A normal 125KHz signal without the correct requesting vehicle information will not wake up the key; this reduces the quiescent current draw of the key.The vehicle receives the alarm remote key signal through the alarm remote antenna in the rear spoiler.The signal sent by the key received and evaluated by the kessy through the alarm remote antenna in the rear spoiler. The answer from the key contains a vehicle specific data so that only keys assigned to the vehicles kessy control module are woken up and this after the vehicle implemented wake up.The Kessy evaluates the key data and commands the central locking system to unlock via the rear control module.The communication between the kessey and the Rear control unit is via the comfort CAN bus.Communication path for Keyless Entry- Starting VehicleConfrimation within the igniton switch starts the search for a key within the vehicleWhen the ignition key is inserted in the ignition switch and rotated the "S" circuit is actuated and the switch position is detected (KL15, KL50,) This initiates a search for a transponder in the interior of the vehicle. The search takes place at the same time on the outside of the vehicle by the interior antennas.The key answers the control midule request on the alarm remote radio frequencyThe key receives the 125KHz signal, evaluates this and sends an appropriate response via the alarm remote frequency 315 MHz.The vehicle receives the signal sent by the Kessy and releases the steering lock and enables starting in the DME and KESSY.The signal sent by the key is received by the kessy and evaluated. If the key is confirmed as assigned to the vehicle the starter operation is allowed and DME enable signal (via CAN) is sent. The starter engages and the engine starts.Communication path for keyless entry-Leaving VehicleOperation of the door handle micro switch leads to a key query being sent to the outside area of the vehicleThe micro switch is hardwired to the door control module and the door opening signal is sent to the kessy via the Comfort CAN. The kessy initiates a search for a valid key in the exterior area of the vehicle via the antennas that are intergrated in the door handles.The kessy evaluated the key data and controls the central locking system via the rear control module. The key data is evaluated in the kessy and then a command to lock the vehicle and actuate the alarm function is sent via the Comfort CAN.

See? All very simple...............

Share this post


Link to post
Share on other sites

Sounds like your Kessy has amnesia from a power glitch.

Try resetting it by pulling its power supply fuse.

If no joy, visit your friendly dealer who will reprogram it.

Make sure you take all your keys to the dealer for the reprogram.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Content

    • By loganmarriott
      Hello
      I have a tough question for any advanced Renntech users who have either stripped a 997 back to minimum wiring for racing, or fixed key issues
      Can anyone help with my alarm issues.
      Im building a 997 Track car- using a salvage chassis and the remaining parts from a rolled and written off cabriolet. Im think the key worked to unlock to car before i pulled it apart, but cant be certain as the engine was already out so there were limit functions to activate then.

      Since moving the dashboard and whole wiring loom into race chassis, I can unlock the doors (yes, its the correct key, ive moved the doors over too), and the dashboard lights up to tell me the current odometer values. However the whole time from when the battery is connected, the alarm siren is going off (currently a clamp muffles that noise to save the neighbors). I can put the key in the barrel, rotate, and then still remove it (the Barrel lock appears to electrically be live, as it releases the key).

      My guess if that the key has lost its coding for the alarm system, but I've tried following these instructions, https://rennlist.com/forums/997-foru...working-2.html,
      with all combinations of button holding, pushing the hazard light switch, foot on brake, and key in/out barrel .... without any success in recoding the key.
      Its worth noting the windows dont go through the usual drop down upon lifting the door latch sequence, im assuming this is due to the alarm running.

      Any suggestions.
      - my options seem to be getting the local agent to reprogram the key
      - are there any other steps i should try to revive the key. I do only have 1 for the wrecked chassis's system

      - a final last though is am i missing some switch that needs bridging from the cabriolet circuits to tell if the roof is down/up

      Regards
      Logan Marriott


    • By aureliusmaxed
      Troubleshooting a no crank issue; this code came up on the durametric alarm module section.
       
      My alldata documentation goes on to state;
       
       
      What does this even mean ? An entirely defective door lock module ? Did a previous owner install one from another car ? I don't really understand because the troubleshooting step is just one possible simple solution.
      I will carefully test all operation of the door lock and update with another post. 
    • By elc32955
      Found another issue I'm trying to sort out. My Cayenne is optioned with Entry & Drive, however when I purchased the vehicle a few weeks ago the former owner did not have the dummy plastic Entry and Drive key. I ordered a new key and it came in the other day.
      The remotes are both working correctly, the vehicle is locking and unlocking like it should, all door buttons work on the outside. The problem appears to be the ignition cylinder. When the plastic E&D key is put into the lock, it goes in OK all the way, but has very hard resistance turning one position to the right although it does go. It will not turn to the start position to start the vehicle. From center it will turn to the left with no problem and then back to center OK. I've also noted the key can be removed in the "on" position where it would normally not be able to. Both flip keys work the cylinder flawlessly in all positions.
      Am I doing something wrong here or could I just have a faulty cylinder? My first thought was can the cylinder be lubed and if so what would be the correct lubricant to use? Don't want to shoot it with something that will zorch the lock & then be towed to the kindly dealer. I'm sure the plastic key is fine, it was a new Porsche part in the bag.
      Thanks
      Eric
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.