Keyless (kessy) entry problem fixed ! after 5 dollars and 1 hour o

[lewisweller]

Hi all,

My kessy was not working for entry/exit or the Dummy key. I replaced the mosfet and resistors in my kessy and works a treat now. I found only one mosfet was damaged but changed both anyway and 3 resistors which obviously was for the blown mosfet. The key is the drain ie the back of the mosfet soldered onto the pcb, this must be a solid solder sandwich or the mosfet won't work well or sometime at all. I did it 3 times to get it good. You can hear a sound like a crack when the solder is going to liquid and the pressure applied to the mosfet pushing it down with a screw driver to make the contact point for the solder to melt.

I also smeared the solder on the pcb evenly prior to trying to solder the mosfet drain on.

The kessy is under the drivers side dash panel nearest the center console, so water ingress is doubtful.

Battery drain could be many electrical circuits, there was a how to I read about connecting amp meter to battery and pulling fuses to determine the Power drain source.

Note the mosfet I had where different to the other people's that I copied the part order from, so when I opened it up and saw they where different, I had to reorder from mouser the correct ones.

[Kikokiko1976]

Hi,
Sorry to revive this thread, i just did this fix but after connecting the module fuse 41(kessy fuse)keeps blowing, please help.
Thanks


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[lewisweller]

4 hours ago, Kikokiko1976 said:

Hi,
Sorry to revive this thread, i just did this fix but after connecting the module fuse 41(kessy fuse)keeps blowing, please help.
Thanks


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Got any pictures of your pcb when it was out? What did you find was wrong when testing the resistors and mosfets? Check your dtc codes as I expect you will have a short to earth on an Antenna maybe if the module is not the problem. 

[Kikokiko1976]

Before the repair i cannot communicate with the Kessy, so i cannot check the dtc codes with durametric. My build had keyless entry but doesnt work and key fob was working intermittent so i had a go at it. Now fuse keeps blowing and no ignition


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[Kikokiko1976]

There was a rear convenience module error if its somehow connected


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[Kikokiko1976]

Update, fuse did not blow now but still no working kessy.ill just leave it as it is. I can still open/lock(arm) thru the fob. [emoji4]


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[Kira Langolf]

I'm wondering if the solution discussed in this thread will solve my KESSY problem: 99.9% of the time, unlocking the doors with the fob doesn't work, yes I've changed the battery! However, if I lift on the rear hatch entry handle (hope that makes sens) and THEN press the fob, it unlocks. I feel like I have to grab my cayenne's *** just to get the remote to work, LOL!

 

The door touch unlocking system hasn't worked in years. Was repaired at dealer while under extended warranty but failed shortly after (and after warranty expired). I miss this feature :( and have been searching for a solution.  I can't seem to find any similar symptoms and this thread seems to be close.  I'm thinking this repair would be a good place to start? Any other suggestions are greatly appreciated!

 

PS-Thank you to all of you that contribute on this forum! Thanks to this forum, I've been able to repair and replace parts myself and save a ton. Some repairs I have documented and put on Youtube (https://youtu.be/txTxRET7vew) mostly for myself to remember what I did, but also it may help someone else! 

 

[lewisweller]

19 minutes ago, Kira Langolf said:

I'm wondering if the solution discussed in this thread will solve my KESSY problem: 99.9% of the time, unlocking the doors with the fob doesn't work, yes I've changed the battery! However, if I lift on the rear hatch entry handle (hope that makes sens) and THEN press the fob, it unlocks. I feel like I have to grab my cayenne's *** just to get the remote to work, LOL!

 

The door touch unlocking system hasn't worked in years. Was repaired at dealer while under extended warranty but failed shortly after (and after warranty expired). I miss this feature :( and have been searching for a solution.  I can't seem to find any similar symptoms and this thread seems to be close.  I'm thinking this repair would be a good place to start? Any other suggestions are greatly appreciated!

 

PS-Thank you to all of you that contribute on this forum! Thanks to this forum, I've been able to repair and replace parts myself and save a ton. Some repairs I have documented and put on Youtube (https://youtu.be/txTxRET7vew) mostly for myself to remember what I did, but also it may help someone else! 

 

Does the dummy key work? If not then I suspect the mosfets and or the MELT resistors are blown. Also even if the mosfet sink soldering to the pcb is poorly done or weakened the antennas work badly or not at all. 

 

Edited May 12, 2017 by lewisweller

[Kira Langolf]

Thanks for your response!   Yes, the dummy key works.

 

Is there a guide to show how to get to the module?

 

PS I still have no idea why touching the tailgate handle enables the fob to function.

[lewisweller]

3 hours ago, Kira Langolf said:

Thanks for your response!   Yes, the dummy key works.

 

Is there a guide to show how to get to the module?

 

PS I still have no idea why touching the tailgate handle enables the fob to function.

This sounds like the antenna are weak but must still work because otherwise the rear hatch won't open. 

Due to the low cost I would go ahead and replace the mosfets and melt resistors making sure the sink soldering is spot on. I reckon this will fix all your problems. If not then it may be an issue with the key and something between the rear comfort control module and the kessy is wrong. Check clarksongli DIY link

Edited May 12, 2017 by lewisweller

[Brit6]

As you can probably see from this thread, i had the same problem, My dummy key always works, but my handles stopped working. I replaced the MOSFETS and MELT resistors and then everything started working again.

 

But, they blew again and i replaced them a second time! and guess what they went one more time just last year, i have not replaced them for a third time because something is blowing them out after a couple months of use.

 

I am going to investigate when it take it out of storage probably in the fall. My guess is rear end control (comfort) module (I have heard these are known to fail), tilt sensor, or passenger compartment monitoring sensor.

 

Kira Langolf: The reason it works when you press on the rear hatch entry handle is that when you do that it sends almost like a wakeup command to the KESSY module and then your key fob will work. My money is on the MOSFETS and MELT resistors, give it a go and go from there!

Edited May 12, 2017 by Brit6

[Brit6]

3 hours ago, Kira Langolf said:

Thanks for your response!   Yes, the dummy key works.

 

Is there a guide to show how to get to the module?

 

PS I still have no idea why touching the tailgate handle enables the fob to function.

The module is a little difficult to get to and even harder to install back. I am not sure if there is a guide online, but there should be, i'll try and look.

[Kira Langolf]

A soldering I will go! I have found the tutorial for removal of the module and the photos don't show. 

they would be very helpful, is there any other place they may be? Thanks for all the help!

Whoops! The pics are at the beginning of this thread!

Edited January 23, 2018 by Kira Langolf

[andrewjt19]

On 12/10/2013 at 5:05 PM, Brit6 said:

Well I replaced the 2 Mosfets and the 6 resistors. I plugged the KESSY unit back in and it said "Ignition Faulty" then it started right up with the Porsche Entry & Drive dummy Key. I drove the car a bit and then tested the locking button on the drivers side and it worked again! The unlocking by touching the handle is also working on the front driver side door and the front passenger side door. My tailgate also works fine again.

The only thing I have a question for is that neither of my rear doors open while touching the handle, I am guessing this is not normal? Can anyone confirm?

I'm looking into the issues here for a different reason, but I think the problem you're experiencing is a failure of the rear control module. Do your Comfort settings reset instead of retaining them? This might be your issue. As far as my issue, I'm trying to find part numbers for the exterior antennas for the key fob alarm. It has something to do with the kessy system, but I'm not entirely sure how. I know the interior antennas are related to the keyless start, etc.. 

[Brit6]

16 hours ago, andrewjt19 said:

I'm looking into the issues here for a different reason, but I think the problem you're experiencing is a failure of the rear control module. Do your Comfort settings reset instead of retaining them? This might be your issue. As far as my issue, I'm trying to find part numbers for the exterior antennas for the key fob alarm. It has something to do with the kessy system, but I'm not entirely sure how. I know the interior antennas are related to the keyless start, etc.. 

Yeah, that seems to be what it is boiling down to. I will try and replace my rear end control module this summer and then re-do the 2 mosfets and 6 resistors and see what happens. I'll report back.

 

I can help you find the part numbers, why do you believe that you need new exterior antennas?

[andrewjt19]

Yeah, that seems to be what it is boiling down to. I will try and replace my rear end control module this summer and then re-do the 2 mosfets and 6 resistors and see what happens. I'll report back.
 
I can help you find the part numbers, why do you believe that you need new exterior antennas?

Question for you... Do you remember the part number for the rear control module? I need to change mine too... Any info would help. Was the process to changing it difficult?

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[Brit6]

On ‎25‎/‎01‎/‎2018 at 12:44 PM, andrewjt19 said:

Question for you... Do you remember the part number for the rear control module? I need to change mine too... Any info would help. Was the process to changing it difficult?

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I have it written down, i'll try and dig it out, but they will be different depending on model.

[andrewjt19]

46 minutes ago, Brit6 said:

I have it written down, i'll try and dig it out, but they will be different depending on model.

Sounds good. I'm looking for a 2004 Cayenne Turbo of that's what you had... Either way it can get me started. Thanks

[cdibi]

I have a 2006 Touareg with some issues that I believe are related to this thread. 

 

My keyless entry works properly on all 4 doors, but the rear hatch keyless does not work. The other problem that I am having is the panic alarm siren is going on and off randomly at all different times of the day. Upon bringing it to the VW dealer they said they found DTC for both passenger side door handles, rear bumper antennas and alarm horn. Quoted $2,300 to fix which I won't do on this old of a car. They disabled the alarm system temporarily by pulling the fuse. 

 

I have also been getting an occasional mystery clicking sound in or under the dash that lasts for 10-15 seconds at a time. 

 

As a side note, I installed a push button start system myself when I originally purchased the car which has always worked fine.

 

Has anyone had or heard of this situation. 

[ttocs]

cdibi, the alarm siren randomly actuating can happen due to a sensor that is failing. I had a non-VW/Porsche that sounded the alarm randomly and it was due to a failing front hood latch sensor that made the security system think the hood was open when in fact it wasn't.

[cdibi]

How would you go about figuring out which sensor is the issue? Any tips?

 

[ttocs]

While I'm certain there's a logical way to investigate which faulty sensor might be "the one", I'm not educated enough to know this, so I would begin at the rear hatch since it is something that the fob can't control.

 

But, I question what else might be happening, especially with the mystery clicking. Could the clicking be related to your installed push button start? Relay? Sparking?

 

Here's a thought, I'm familiar with some of the weird things that can happen when a older Porsche has a battery that is slightly under-voltage. In other words, it works fine, seems normal, it'll start the car etc, but when tested is just a little low. When it happened to me it triggered Limp Mode on my Tiptronic so it would only shift up to 3rd gear, and a fault code was generated saying a "multifunction switch" was bad. It just so happens that my battery was tested a week prior and it was found that the voltage was low. After replacing the battery and clearing the code, nothing weird happened again, and that was 3 years ago.

[Juve1982]

Hi all

 

Just wanted to say a Big Thank You! If you want to know why ...

 

I had issues with my Cayenne Turbo 957 since last December, it all started with a dead battery. I installed a new one and everything worked fine for about one or two days. Then again, battery dead. First I thought the new battery had issues, I recharged it and it was fine for again one or two days. Then I started reading myself through various (German) forums and heard something about this forum and a potential solution. While reading through, I realized that my outdoor sensors were also not working since the problem initially came up (nevertheless the plastic dummy worked to start the engine). So I started doing some measures and realized that after about 15 minutes the current drain jumps from 30 mA to 3-5 A. Obviously something was messing it up, I removed the Kessy unit and checked the MOSFETs as described in this forum. It turned out both MOSFETs had a short circuit. It was not easy to find fitting MOSFETs since westlforidacomponents.com does practically not ship to Switzerland. But I found similar components on Mouser 942-AUIRFZ24NSTRL which I ordered and managed to install today. I gave it a shot and did my very first soldering at all with this task. To be honest, the solder points look very bad and I had big problems desoldering the broken MOSFETs, also I thought I messed up some other components because I mistakenly desoldered them and had to fix it somehow.

 

Then the moment of truth, I reinstalled Kessy and checked the outdoor sensors --> no luck ? .

Then I drove a few minutes, parked the car and checked again, and yaaaay ? outdoor sensors work, locking and unlocking seems to be fine.

Then the second test, current drain measurement: After approximately 30 minutes there seems to be no wrong current drain, it remains at around 30 mA.

Third and last test will follow next week when the car stays in the garage for a few days and hopefully does not empty the battery. Will keep you updated.

 

Again, many thanks for the great help!!!

[Alexandru Bigu]

On 5/16/2017 at 10:55 AM, Kira Langolf said:

A soldering I will go! I have found the tutorial for removal of the module and the photos don't show. 

they would be very helpful, is there any other place they may be? Thanks for all the help!

Whoops! The pics are at the beginning of this thread!

were you able to locate the pictures?

i am also trying to perform this repair, and am out of luck finding the pictures.

[Alexandru Bigu]

On 11/26/2013 at 3:40 PM, clarksongli said:

i posted a DIY in common fixes and repairs. there is a link there

FYI...these resistors sit across the drain of the transistors, if the resistors are blown, it's because one of the mosfets is bad.

Translation, replace everything at once (2 transistors and all 6 resistors.

Do you happen to still have the pictures for this tutorial? they do not seem to be available any longer.

thanks.