Intermittent Immobiliser Fault

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akp25
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Intermittent Immobiliser Fault

Post by akp25 »

Hi all,

I recently bought a VW Polo 2002 plate 1.4 SE and it's having a very weird intermittent immobiliser fault. Sometimes the car will start and run just fine however other times the immobiliser light will start flashing when turning the key and prevent the car from starting. The immobiliser light sometimes disappears after around 10 mins, otherwise I have to leave the car be for a few hours before trying again, and then it's fine. A solution which has normally worked is to disconnect the battery and drain the residual charge before reconnecting however even this is failing to work now.

The AA had sent a VW specialist to who looked at the car, he couldn't tell what was wrong with it. He did mention that there was some water near the fuses near the driver footwell, which was obviously cause for concern. He managed to find a temporary fix by disconnecting and reconnecting the instrument cluster - I have not done this again.

Have any of you experienced similar problems to this? My best guess is that the instrument cluster is faulty as I've read that dry solded/cracked joints is a common fault on Polo clusters.
RUM4MO
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Re: Intermittent Immobiliser Fault

Post by RUM4MO »

I've read, on www.briskoda.net (Fabia Mk1 section) that if you flex the steering column a bit, ie unlock clamp and move wheel in/out and up/down, you might get a quicker short term fix.

Also, yes, I've read that the real fix includes re-soldering some plug contacts on the pod. It is the wiring from the engine immobiliser aerial near the ignition switch that seems to be the problem - or its contact pins on the dash pod.

Maybe have a look at that other forum site as I think that this has been discussed recently along with links to some older threads with pictures. Warning:- some people have replaced the ignition switch/aerial assembly and this has fixed things for a while, but doing that flexes the wiring so I said above - and that is what is making things work better not normally the new ignition switch/aerial assembly.
akp25
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Re: Intermittent Immobiliser Fault

Post by akp25 »

Right okay, many thanks for your advice RUM4MO. I've currently dropped the car off at an auto electricians for a full scan, I presume the codes which will be produced will be tbe Engine Start Blocked By Immobiliser and Key Signal Too Low as these seem to be the most common occurrences for problems of this type.

Do you think that I should try and fix the instrument cluster myself? I have a fair bit of experience soldering but I've seen companies online that offer instrument cluster repairs at a reasonable price so I'm thinking it might just be best to send it off to them.
RUM4MO
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Re: Intermittent Immobiliser Fault

Post by RUM4MO »

As long as you are happy enough with removing the dash pod - I'm guessing that that will be the hard bit, re-soldering a few well spaced contact pins should not cause you much grief. I've never had this problem or seen first hand what these dash pod connectors etc look like, but is there not some pictures on the Skoda forum site that would give you some idea before you start. I'd guess that you would need to join that forum to look at these pictures, but that will not be a problem and it is currently a good source for info on your age/model of Polo. Maybe extend your search to www.seatcupra.net as well as it should have been discussed there as well as it is as you say a common problem across this platform.
akp25
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Re: Intermittent Immobiliser Fault

Post by akp25 »

Got the car back from the auto-electrician today, there was only one fault code relating to the immo - Engine Start Blocked By Immobiliser. I took the instrument cluster out just now and I was looking at some of the connections. I've posted two pictures on here, showing the worst of the connections; do the parts circled in red look dodgy? Also when I plugged the instrument cluster back in, there were 3 beeps and then the handbrake light kept flashing :?: The oil light was flashing too but that went away by itself. Could this mean that the wiring is dodgy? Thanks

Image
Image

https://s31.postimg.org/a4fvnc94r/immo1.jpg
https://s31.postimg.org/9syfaksor/immo2.jpg
RUM4MO
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Re: Intermittent Immobiliser Fault

Post by RUM4MO »

I'd think that reflowing all these pins can't be a bad thing. Have you looked at the www.briskoda.net threads and pictures on this topic?
RUM4MO
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Re: Intermittent Immobiliser Fault

Post by RUM4MO »

akp25
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Re: Intermittent Immobiliser Fault

Post by akp25 »

SOLVED resoldering the pins on the instrument cluster has solved the problem (no immobiliser warning light for the past few days). Thanks for your help RUM4MO!
RUM4MO
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Re: Intermittent Immobiliser Fault

Post by RUM4MO »

Well that is good enough!
Damo642
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Re: Intermittent Immobiliser Fault

Post by Damo642 »

I solved the intermittent problem on my 2002 polo by removing the instrument cluster and disconnecting the 2 ribbon cables from the cluster and reinserting them. Sorted.Note we also left the plastic near the key barel in case that makes the key go closer to the reader on the barrel. I dont think that matters but i thought id add that comment also. By the way on my car, the immobiliser would flash every 6 months or so. Wait 10 mins try again. No big deal. 2 weeks ago it started happening 4 startups out of 5. I tried the spare key and that had no effect so i knew it wasnt the key. Description at start of this comment fixed the issue so must of been a dodgy connection or something. Takes 20 mins to do and is worth the effort.
Crazie81
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Re: Intermittent Immobiliser Fault

Post by Crazie81 »

Hi I'm having the same issue with my girlfriend's 1.4 auto. Does anyone have any pictures of the circuit board where the contacts may need soldiering? Many thanks
Laurenk1324
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Re: Intermittent Immobiliser Fault

Post by Laurenk1324 »

Evening, I have been reading through this thread as I have been having the exact same issue with my 2002 polo. However I have posed these ideas to my garage who have been working on the car and he says none of them seem to be an issue. I have had the key barrel replaced. I just don’t know what to do now. Any suggested would be greatly appreciated
Lauren
jurling
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Re: Intermittent Immobiliser Fault

Post by jurling »

Lauren (Laurenk1234)

I have had exactly the same experience. Let's keep each other posted.

John

jurling
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Re: Intermittent Immobiliser Fault

Post by jurling »

Lauren,

I have also now had the instrument cluster refitted and had no problems for a few days but the immobiliser light stayed on today and the car would not start. I just kept switching the ignition on and off until it stayed out. Then the car started okay. But will it next time. 90 per cent of current driving is to and from the garage!

Hope you have been luckier.

John
PeterAbbott
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Re: Intermittent Immobiliser Fault

Post by PeterAbbott »

Crazie81 wrote: Sun Aug 26, 2018 9:38 am Hi I'm having the same issue with my girlfriend's 1.4 auto. Does anyone have any pictures of the circuit board where the contacts may need soldiering? Many thanks
Seems to have the same fault as my 2001 auto. Bit bad on mine as it cuts out at junctions. As advised I have replaced cam and crank sensors and sadly it now comes down to immobiliser ! Reasons all the helpful comments on here I will take a look at the soldered connections on the instrument cluster. Good luck with yours and keep posting if any more info
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