KESSY starting issue after changing key battery

[roblings]

So the battery in my key ran out the other day...

 

I unlocked the car fine with the remote, but when I went to start the engine, It said 'Key not detected' on the display. No problem, I touched the key on the Start/Stop button and started the engine that way, then carried on to work. Left the car unlocked in the work car park (couldn't be bothered to faff with the lock cover on the door) and then drove home in the same manner. Car was moaning every so often that the key wasn't found. Once home, I changed the battery in the key, and locked the car - no problems.

 

Went to use the car again two days later. Unlocked no problem, but again on trying to start the engine it said 'key not detected'. Again I had to start the engine with the key next to the Start/Stop button. I have since tried using the key in the door lock to synchronise the key, but the remote locking works fine - so that isn't the issue. Tried the spare key and that works without a problem - so it's not a problem with the car, it's specific to that key.

 

I have changed the key batteries before, although previously I've done it prior to driving the car when the old battery has failed. I can't imagine that I've damaged the key in any way this time around - it seems much more likely to be some kind of synchronisation issue.

 

Anyone got any ideas on how I can get my key working again?

[nta16]

What about swapping over keyfob batteries to see if the problem remains with the keyfob (or battery) - or meter the replacement battery to make sure it's  not a cheap duff one or passed its 'use-by-date'.

 

[roblings]

Good shout - the one in the faulty key read 2.91V, whereas another one from the same pack was 3.23V.

 

Both Energizer batteries and well within their boasted 10yr shelf life! Just a dodgy one I guess. 

 

Glad it was easily resolved - thanks again for the advice.

[nta16]

Happens to the best of us.  😁  If only I'd thought to test the new brake light bulb before I fitted the fish-slippery taillight unit back on the car!  The bulb was cosseted shed stock brand new when bought years earlier, but untested, and I should have know better as I had the exact same thing happen to me a number of years before.

 

Assuming the batteries aren't counterfeit (so, so many items seem to be even Dealerships have been caught out in the past) then there's this to consider -

"This is also relative to the conditions that the battery is stored. Ten years of life are dependent on the temperature conditions that it is stored. The battery is good for ten years if it is stored on room temperature and in relative humid weather." - https://www.large.net/news/8hu43mt.html

 

You're sorted at very little cost so a good result, you lucky  . . .  😁

Edited 7 October, 2021 by nta16

[Warrior193]

Another Fabia3 with this odd problem - I got a panic call from my wife, she and a friend were locked-out of her car at the garden centre 6 miles away, cue quick rescue run after talking her through the emergency unlocking procedure - which just set off the alarm when she opened door! Message on matrix display 'key not found'. No indicator light showing on key fob when buttons pressed.

Replaced fob battery when I got to her (fresh Duracell 2025, BB4 date, 2025) - still nothing, OK, dead fob I thought! Fortunately I had taken the spare key with me, which got her back home.

Once home I tested the new battery in the non-functioning fob - 3.28 volts but still no indicator light showing when buttons pressed! then tried swapping over with the old battery from my Octavia (non kessy) fob - Fabia fob now working correctly! I can only guess that the new Duracell battery has some internal fault, even though the voltage output is ok on a DMM! 

I guess it's time to reorder fresh cells from another brand.

 

 

[rum4mo]

Panasonic seems to be the battery brand of choice for VW Group from factory, so I've tended to replace with same always bought online from hopefully proper sources.

 

Duracell is my battery of choice for AA and AAA and maybe some small coil cells, but so far never for car keyfobs.

 

Edit:- okay I messed up once for my wife's 2015 VW Polo when I got it into my head that I needed Sony batteries, that worked okay though the seller said in future there would not be any Sony coin cell batteries of this size due to Sony pulling out of that market.

Edited 28 November, 2021 by rum4mo

[nta16]

Warrior193, did you resynchronise the keyfob?

 

It's very simple, directions in the Driver's Handbook (Owner's Manual).

 

Personally I have little faith in digital multi-meters, especially if over 12 months old, unless they are higher priced, cheap ones generally are a waste of materials and resources there ought to be a law against such products being made. 

 

I always suggest (but didn't above?) resynchronising the remote keyfob when changing its battery - and resynchronise both remote keyfobs when changing the car battery where it instructed or not.

 

I also recommend alternating the use of both remote keyfobs in some way that way there is even wear of the batteries, key blades and key locks (perhaps just ignition) plus it means you know where "the spare" key is and that it works.

 

Edited 28 November, 2021 by nta16

[Warrior193]

Re-sync of either fob for the Fabia was not necessary, all ok once I got new battery fitted.

Oddly, the fob battery for the Octavia failed this morning, got the car open at home - but with a warning 'replace key battery', drove to work and fob wouldn't lock vehicle!

Another P$%y Duracell! 

Now fitting all fobs with fresh energizers. 

[nta16]

35 minutes ago, Warrior193 said:

Re-sync of either fob for the Fabia was not necessary, all ok once I got new battery fitted.

Personally I would still resynchronise them as if there is a problem with the system, or battery getting too low, you may not realise it straight away and tend to press the remote key fobs buttons more and/or harder wearing the battery and keyfob more, don't wait for the mummy warning messages, prevention is better than cure and often less expensive - but if it continues to work fine fair enough.

 

Also might be worth checking your car battery's state of charge, especially this time of year, as the over-complicated VW computer programming can throw wobblies when the computers feel low.

 

 

40 minutes ago, Warrior193 said:

Oddly, the fob battery for the Octavia failed this morning, got the car open at home - but with a warning 'replace key battery', drove to work and fob wouldn't lock vehicle!

Are you sure it didn't need resynchronising.  😄

 

 

41 minutes ago, Warrior193 said:

Another P$%y Duracell! 

If you are sure they're not knock-offs then contact Duracell.