Weird KESSY trunk alarm problem

[RWI]

Hello,

 

I have weird problem with opening and closing trunk using KESSY. Successful scenario should look like this:

1. I approach locked car with key fob in my pocket,
2. I open trunk with button located on tailgate,
3. Alarm turns off, trunk opens but doors still remains closed,
4. I close trunk and alarm gets immidiately activated again, I can go away from car.

 

But since like two days opening trunk will cause alarm to deactivate, all doors are being unlocked and closing trunk won't reactivate alarm, scenario now goes like this:

1. I approach locked car with key fob in my pocket,
2. I open trunk with button located on tailgate,
3. Alarm turns off, trunk and doors will open,
4. After closing trunk nothing happens, I have to lock car with sensor in front door handle or button on the key fob.

 

Interesting thing is that opening trunk with button on key fob works fine, alarm activates right after closing trunk. I tried to change key fob batterry but it didn't help.

So it seems that opening trunk works just like opening front door with KESSY. Are there some kind of settings or something I could change earlier by accident? Did anyone had similar problem?

 

Best regards,

RWI

[nta16]

Hi, welcome.

 

Have a look in your Driver's Handbook  (Owner's Manual) you may need to resynchronise the keyfob after changing the battery (I always do regardless).  Check the keyfob battery is fully fitted correctly, that the battery is of the correct type (number) and is a good quality battery as cheap ones wear quicker and can play up.

 

For the boot check to see if it's anything you can select in one of the car's menu, on the car or look in the book, we don't have KESSY so I'm not familiar with it.

 

Edited 10 December, 2021 by nta16

[RWI]

Thanks for your suggestion @nta16. I tried the following:

1. Key resynchronisation according to users manual,
2. I pulled out KESSY and central lock module fuses and waited for around 15 minutes before putting them back,
3. Changing key fob batterry (mentioned earlier) ,
4. Opening trunk with spare key fob,
5. Reading errors with ELM327, no errors found (not sure if such cheap toy would show me kessy related errors anyway)

 

None of these things worked, it still acts the same. Does anybody know where kessy module is located? Are there any antennas or modules at the back of the car? I had minor paint job (scratches) done quite recently, rear bumper and tailgate trim were probably removed, maybe something was not connected back properly.

[nta16]

1 hour ago, RWI said:

Reading errors with ELM327, no errors found (not sure if such cheap toy would show me kessy related errors anyway)

From reading about someone else with that scan tool they seem to be very low level (reader) so may miss stuff but also there can be many faults the dumb computer programs won't give error codes for and the error codes can be very raw data so just pointers.

 

I think you done all I can think of, other than checking the car battery is very well charged.

 

 

1 hour ago, RWI said:

I had minor paint job (scratches) done quite recently, rear bumper and tailgate trim were probably removed, maybe something was not connected back properly.

Now that sounds reasonable, wire or connector perhaps but that should show up on a reasonable scan tool if so, perhaps as a communication error.  A (much) higher level scan tool and you could detect and activate parts to check they're working to perhaps isolate the fault.

 

If work has been done or new parts fitted they're always  suspects to me.

 

If you lived near Northampton my neighbour could try his higher level scan tool, it had 638 lines for the engine in my wife's Fabia alone.

 

Edited 10 December, 2021 by nta16

[RWI]

5 hours ago, nta16 said:

I think you done all I can think of, other than checking the car battery is very well charged.

 

Battery is 1 year old and I drive car regularly for 20-30min. at highway speeds to recharge it, so this was not a problem, hovewer your comment inspired me to do "hard reset". I disconnected both battery terminals. For safety measure I measured voltage on disconnected clamps, it was around 300mV. I waited several minutes for voltage to drop under 100mV and then I shorted clamps together with multimeter set to mA range (it has considerable internal resistance and is fused so it was not hard short circuit).  I waited for a while to discharge capacitors in car modules to be sure that everything will reset. Then I reconnected battery and everything went back to normal! Only time, trip and fuel consumption were deleted, everything else is just fine. Alarm works just like before. This metod of "hard reset" was described by HumbleMechanic on YouTube. I did similar thing but with extra safety measures:

 

 

I hope issue will not come back and someone will find this topic usefull in the future.

[nta16]

Well done on sorting it.

 

It's ironic as I usual put about doing a computer 'turn it-off-'n'-on-agin' by battery disconnect and discharge of stored electric but Sod's Law the one time I don't it'd have worked.

 

With this time of year I've been trying to promote how important the battery is especially on these VWs with their over-complicated and very invasive and intertwined computer programs that can throw up all sorts of wobblies if the car battery gets too low for them even if the car does start and the lights seem bright enough.  Many find the idea of a low battery causing all the problems very hard and take a lot of convincing or just don't believe it.

 

Problem is with complicated issues many want the sexy complicated, sometimes 'look how clever I am' and sexy solutions rather than the really clever simple , quick, no or low cost solutions and they can't believe how dumb the computers are and the computers get so confused and messed up.

 

The video's not bad, he could have cleaned the battery post clamps a little though, crud grit was dropping off one at least but I might use that video as previous ones I didn't save.

 

Cheers.