GolfGTIforum.co.uk

Model specific boards => Golf mk4 => Topic started by: xpeterpx on 27 June 2009, 13:36

Title: Replacing an engine ECU advice
Post by: xpeterpx on 27 June 2009, 13:36
I'm going to replace my ECU in the week and would like to know what involved in doing this.Removal and replacing Im ok on but can anyone please confirm if I'll have any issues with the keys,immobilser etc not matching the ECU(only replacing ecu like for like)?
Also is it just a matter of popping the new one in and resetting the ECU with vagcom and away you go or is there any more involved..?

Thanks for any advice
Peter
Title: Re: Replacing an engine ECU advice
Post by: dai-cymru on 27 June 2009, 17:02
you need to get the ecu ,clocks and keys matched to each other mate for the immobilser   :smiley:
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 29 June 2009, 11:14
Cheers mate.
Should have mentioned that its a Bora,but that prob should not matter.

Just to clarify-there isnt a seperate ECU for the immobiliser is there which woudl mean that the keys are programmed to that rather than the engine ECU?Cant remember if I read that somehere ages ago..

Thanks for the ongoing help
Peter
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 29 June 2009, 11:30
It's the BSI unit that controls the immobilsier and not the ECU.
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 29 June 2009, 11:46
Ah cheers Ben -sounds liek I can just pop in the replacement ECU and reset it and not have to worry about reprogramming keys immobiliser etc?
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 29 June 2009, 11:51
Not so simple I'm afraid - The ECU might not recognise the BSI! You can always "virginise" the BSI unit, but this will disable the immobiliser altogether!

Why do you want to replace your ECU out of interest? It's a pig of a job.
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 29 June 2009, 12:04
Cheers mate
I found this on replacement-my ECU is in a similar place so dont look too bad.

http://www.scribd.com/doc/5875768/Volkswagen-GolfJetta-18T-and-VR6-ECU-Removal-How-to

and this on how to program a replacement one in as I have full vagcom:
http://www.ross-tech.com/vag-com/cars/immobilizer2.html

Just checking now if I have Immobiliser 2.

Glad I asked here too as I cant find any mention of any conflict problems
Cheers for the ongoing help
Pete
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 29 June 2009, 12:25
Quote
Glad I asked here too as I cant find any mention of any conflict problems

I'm not saying there definately will be a conflict - just that there could be. Just speaking from experience. Someone I know has a Citroen Xsara (diesel). The ECU has screwed itself, which in turn has screwed the BSI unit and the car cannot be used at all! Re-coding the ECU and replacing the BSI has not solved the problem!
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 29 June 2009, 14:11
Cheers mate

Think I need to investigate this a bit more before I s*d something up......................

pete
Title: Re: Replacing an engine ECU advice
Post by: Rhyso on 29 June 2009, 14:15
out of interest why are you replacing your ECU?
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 29 June 2009, 14:21
I've been trying so solve the unsolvable and have exhausted all other possiblilites on my lumpy idling problem(-see my earlier post).I know it a long shot and extreme but I'm fortunate enough to have had a spare one offered by a mate whos breaking his mk4 so just thought it might be a simple plug and play/recode operation as I have full vagcom access.
 
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 29 June 2009, 14:24
Quote
I've been trying so solve the unsolvable and have exhausted all other possiblilites on my lumpy idling problem(-see my earlier post).I know it a long shot and extreme but I'm fortunate enough to have had a spare one offered by a mate whos breaking his mk4 so just thought it might be a simple plug and play/recode operation as I have full vagcom access.

I wouldn't have thought this would solve the problem. Have you tried the usual?

- split leads/hoses
- coil pack
- spark plugs

Have you scanned it to see if it chucks out any fault codes???
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 29 June 2009, 14:30
Yes mate went over the breather pipes at the weekend and couldn't spot anything sinister.Also changed the fuel filter to eliminate that too..
http://www.golfgtiforum.co.uk/index.php?topic=121046.0

Scanned many times with the full registered version of vagcom and comes up clear every time!
Title: Re: Replacing an engine ECU advice
Post by: Rhyso on 29 June 2009, 14:31
i'd be very surprised if it was an ECU problem - you don't tend to hear of them going wrong  :undecided:

is it not something like a gasket or seal perished??
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 29 June 2009, 14:46
Possibly,but where would I start with checking? Are there any 'notorious' ones on the mk4 I could start with?
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 29 June 2009, 14:51
I can't remember the name of the valve (think it might be EGR), but that can sometimes get clogged up with crap and cause performance problems???
Title: Re: Replacing an engine ECU advice
Post by: Rhyso on 29 June 2009, 14:57
Possibly,but where would I start with checking? Are there any 'notorious' ones on the mk4 I could start with?

inlet and exhaust manifold gaskets maybe??

I can't remember the name of the valve (think it might be EGR), but that can sometimes get clogged up with crap and cause performance problems???

i believe they are fitted to diesels only mate
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 29 June 2009, 14:58
Just read the original thread - it was the TB I was on about :embarassed: and yes, it's been cleaned already!
Title: Re: Replacing an engine ECU advice
Post by: dai-cymru on 29 June 2009, 16:49
whats the bsi unit?
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 29 June 2009, 19:12
Quote
whats the bsi unit?

The BSI unit controls a number of basic functions including indicators, ignition lights on with the key, cluster readings and also aids in starting the engine by talking to the ECU to engage/disengage the immobiliser :nerd:.
Title: Re: Replacing an engine ECU advice
Post by: dai-cymru on 29 June 2009, 19:15
Quote
whats the bsi unit?

The BSI unit controls a number of basic functions including indicators, ignition lights on with the key, cluster readings and also aids in starting the engine by talking to the ECU to engage/disengage the immobiliser :nerd:.

ah right when i did the engine conversion i had to send the clocks ecu and key off to be matched together for the immob, didnt know about a bsi unit or is it inside the clocks?
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 29 June 2009, 20:07
Quote
didnt know about a bsi unit or is it inside the clocks?

Nah mate, it's an actual chip like the ECU.
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 30 June 2009, 12:03
Is it worth asking the guys at R-Tech for the definitive answer on this even though its not a remap?
Title: Re: Replacing an engine ECU advice
Post by: Ben_1uk on 30 June 2009, 12:06
Possibly if your convinced its ECU related...
Title: Re: Replacing an engine ECU advice
Post by: Rhyso on 30 June 2009, 12:09
Is it worth asking the guys at R-Tech for the definitive answer on this even though its not a remap?

always worth a phone call mate

whereabouts in the country are you??
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 30 June 2009, 12:21
East Hertfordshire
Title: Re: Replacing an engine ECU advice
Post by: Rhyso on 30 June 2009, 12:30
maybe a bit far - they're in Hinckley, Leceistershire - approx 90 miles from you or so depending on your exact location

give them a ring and see what they say  :smiley:
Title: Re: Replacing an engine ECU advice
Post by: xpeterpx on 30 June 2009, 12:42
Cheers guys and can I just say that I appreciate all the advice given

Pete