Key wont disarm the imobiliser.

Mr K · #1 4th September 2010, 12:24 PM

I have just replaced the battery in my spare key, i had to reset the key (press unlock, then unlock the car physically with the key within 1mins) and the fob now disarms the alarm and unlocks the car fine, but it wont disable the imobiliser; the car just starts and runs for a second before it cuts out.

My other key, and the 'wallet' key all work fine.

Any ideas whats up?

PsYcHe · #2 4th September 2010, 01:50 PM

The only one I can think of is that the immobiliser has forgotten about the key (or never knew about it in the first place). I think there's a VCDS procedure to re-code it, or you may need to speak to Shark Performance (or see if ben at AVP can help).

Found the link: http://www.ross-tech.com/vag-com/cars/immobilizer.html

ainarssems · #3 5th September 2010, 07:28 AM

First of all the fact that You changed battery should not have anything to do with immobilizer because immo transponder does not use battery.

I have had similar problem on A6 wher immo would recognise one key all the time and other key sometimes would work for several weeks and then not work for some time.

I think it is bad connection in wires/plug coming to immo coil or coil itself by the ingnition lock. It just happens that one key is more sensitive/powerfull then the other and works better.

And chances of immo forgetting one key is next to none.

Exerqtor · #4 28th December 2010, 03:31 PM

I think i can have a simular problem on my car now.

My coil tube gaskets on right side struck leek last week, so the car stood stil until last night when i tryed to start it so that i could drive it to my workshop. First of al the battery was dead, not that weird since it has been somewhere around -20 C the last week. But anyways. I charged the battery for 30mins and boosted, so that i could start. It started right away and i drove it to my workshop, so it could de-ice over night. Now when i got there today i was going to start it so that i could drive out one of the other car's i have standings to get more space.

BUT, the MID is black, the starter cranks and engine runs for 1 sec. I have went over every fuse and none is dead, only thing strange is that i only have 0.57v on Fuse nr.3 red row.. Anyone know what the f*** this might bee?

PsYcHe · #5 29th December 2010, 09:16 AM

Could it be the infamous corroded earth point?

There's a point where a lot of the earths come together in front of the wheel arch somewhere and that gets covered in crap & corrosion. Give it a clean and see how it goes.

Just_Ben · #6 29th December 2010, 04:34 PM

It's not the earth, that's only the earth for engine starting electrics.
The fault is, as stated, unrelated to the remote battery failing. The imobiliser runs seperately. You DEFINATELY have an imobiliser fault. If one key works then it's not the imobiliser or it's wiring as this would affect both keys. Did the key in question work before? If the car has "forgotten" the key (it shouldn't do but not impossible) then it needs to be re coded with security coding. I can do this but I'm based in Daventry now rather than Burton (AVP) but yeah, Ben Wardle at Shark should be able to do also.

As for the remote (purely for central locking) to re allign you insert the key into ignition and turn igniton on (engine NOT running) then hold Unlock button on key for 10sec. This should bring it back in line but ONLY if the key has previously been coded to that car - this process won't work with a brand new remote and would need VCDS

Exerqtor · #7 29th December 2010, 08:17 PM

Wel, i finaly started the s**t today. Ended up with taking off both battery kables and let them sit for a while. Then re-conected them. Closed everything, hood, windows, doors, sunroof and trunk. Locked, unlocked. And then it started.

BUT my mid has gone totaly crazy. Pic's say more than 1000 words in this case: