my mk3 wont start

[gti_mk3]

have posted this on mk3 forum but no response so trying this one.

My mk3 will not start, and I have recently purchased the VAG COM diagnostic tool. (have already tried plug leads, dizzy etc, and swapped coil with another that I know works)

The VAG COM arrived last week and reads fault code - Immobiliser Implausible signal...??
Had the immobiliser checked by a specialist, nothing wrong with it. He did say however that often there can be a problem with the chip in the ignition key that in turn deactivates the immobiliser

So, took the fascia off around the ignition barrel and there is a plastic collar with a thick black wire leading off it into the loom. It looks like some sort of device that would read from the key when placed in the barrel....

Have read before that people have renewed ignition switches on this forum before and the problem has been solved.. can anyone help on this.?

Cheers 
 
Chris

[gibby]

Come on you mk3 owners, someone must be able to answer the man ! 

[redcarboy]

Get rid of the factory immobiliser and fit a new one thats what i did probably cheaper in the long run..

[Len]

Didnt see this in the Mk3 Section - must have got buried!

Um dont really know coz i aint had this problem.
Did have a glitch recently with the interior light and out of that i heard some stuff about the key and the immobiliser. I know that the ECU is also coded to the key/immobiliser.

Just a thought - if it has to send i signal to ECU it (the key) must have a battery........
Clutching at straws here.

As the Count says.......... got mine done in with the full closure Cat 1 Alarm.

Not much help i'm afraid

[Overseer]

what did the specialist suggest as a fix?


i'd take it to a specialist, pref a VW one that also does alarm installations..

[gti_mk3]

the specialist said that these cars are prone to probs with the ignition switch and the ign key sending a signal to the immobiliser. the battery in the key is for small torch to find the lock in the dark..(but that crossed my mind also)

its looking like I'm gonna have to take it to a VAG dealer (last resort). maybe they'll give me a discount on the fault diagnosis if i take the laptop and the VAG COM cable along...

when I find out what caused it I'll be sure to post it.

cheers for the advice anyways,

Chris

[Overseer]

yeah since i thought the transponder in the key didnt have battery in it,  if you have a spare try that to rule out the key itself.

you say you had the immob checked.. so you got it towed somewhere?

if that were the case..  an alarm specialist should be able to disable the immob pretty quickly...  no matter where the fault is the car would be startable then.. so why is the guy esentially saying the immob is fine.. then saying something related could be at fault?

btw.. dont be scared of VAG.. they arent always that pricey..