Club 80-90 Forums

I'd like to introduce you to Daffy and more specifically his inner workings:


Thus far we've discovered that the engine is a 1.9 diesel from a VW Caddie. With the exception of a new starter motor, fuel lines and coolant pipes all has been well until he stopped working!!

The initial suspect was the fuel pump as we assumed there was no immobiliser or ECU until tucked away in the bottom left hand corner, exposed to all the elements we found this:


I little home spun ECU complete with key!!! Now the problem seems to be decoding said ECU or replacing it all together???

Has anyone seen anything like this or know what to do???

Any advice would be greatly appreciated as Daffy keeps on throwing us a curve ball and until we discovered this latest Heath Robinson affair was running like a dream!!!

Cheers in advance.

there will be apart number for the ecu on the outside of the case so you can get that and go looking on ebay for a used one but I'd be tempted to disconnect the multiplug to the ecu and get the contact cleaner out and give both the plug and the ecu contacts a good going over with that and then reconnect and see if that helps jusging by the road rash that has got wet and warm not ideal for electrical stuff, I take it the engine is turning over fine it's just the ecu not talking to the pump - where's the potentiometer that would have been on the accelerator in the caddie now fitted ? I don't know what other interlocks the caddie would have had, clutch, brake etc...can all be switched on TDis

Thanks for this Aidan. Engine is not turning over. It was, then fuel lines replaced then nowt, which is why the fuel pump got the blame until I said I didn't think it was the pump as I hadn't had any issues with stalling, loss of power etc and asked if it couldn't be something else. Turns out the something else was what was found above.

PS: when you say these can be switched, any ideas on cost? I've just been made redundant and had been planning to use Daffy as my daily drive until a new job came along. If its going to cost a fortune, I'm going to have to rethink this

if engine not turning over then likely it's a starter motor/ignition switch issue unless they have done some clever cross wiring into the T3 loom which I'd be suprised, but maybe the vehicle was often parked somewhere unsafe so they have used the immobiliser stuff fully, but I'd be suprised - pm SyncroAndy on the forum he'll possibly be able to help understand the wiring you have fitted and how the immobiliser works - it's a bit too new fangled for my little brain
ECUs are generally very robust and rarely go wrong but obviously electronics and water aren't best bedfellows
Stick a post in alt engines too with a link back to this post a lot of the weird diesel engine boys don't read mechanical section

Again - thank you so much for yr help and Happy New Year.

Sorry, I can't help with the problem, but at least once you fix the issue you can move the imob ring to your ignition barrell like this



Then split the fob, cut your existing ingnition key blade and insert to the one with the chip. You can never have too much security.

Just a thought is there anywhere you can plug in to VCDS?

ninja.turtle007 wrote:Just a thought is there anywhere you can plug in to VCDS?

Please forgive my ignorance but what is a VCDS??

Hi, looks like you'll have some fun sorting this out ! VCDS = Vagcom Diagnostic System from Ross Tech, software you run on a PC to connect to the ECU for monitoring and diagnosis. Your fault is unlikely to be the ECU itself as they're sealed and pretty bombproof, but it could easily be a wiring fault if your install has been thrown together.. Without getting some diags back from the ECU its difficult to know where to start really. Sadly I'm at the wrong end of the country. Do you have a local friendly mechanic who could assist ?

Soz, just re-read and seen engine is not cranking, that's nowt to do with the TDI electrics, just a basic wiring issue or mechanical fault.

Unless it happens to have the immobiliser relay fitted....discoverered one of these the other day on a p reg sharan...wouldn't crank with a un matched key...a rarity to say the least...lost a bit more hair that day...!

Thanks for all this info. What we know is that it had a new starter motor fitted in Sept so that should be fine. It's fair to say that the wiring to the ECU is somewhat corroded and a bloomin mess. I've got a proper mechanic who and I quote 'loves a good puzzle' but he's also suggested an electronics specialist. He thinks we may need to go back to the drawing board a bit on this in the longer term but I'm looking for a short term fix - can the ECU be bypassed temporarily or recoded to get running with a view to having a proper 'sort out' at a later date? I know that sounds simplistic but I lose my car in 3 weeks and need Daffy running or OH will be making noises about trading him in for a 'reliable runaround'

You can't really bypass the ecu, as it controls everything. Do all your dash warning lights work? Have you checked for power at the starter when the ignition key is in the cranking position? You could try removing the key from the immob ring and then putting it back in. See if it works then? I don't think a key with a chip in it would last long exposed to the elements. You could take the key to your local locksmiths and get a copy of it.

lloydy wrote:You can't really bypass the ecu, as it controls everything. Do all your dash warning lights work? Have you checked for power at the starter when the ignition key is in the cranking position? You could try removing the key from the immob ring and then putting it back in. See if it works then? I don't think a key with a chip in it would last long exposed to the elements. You could take the key to your local locksmiths and get a copy of it.

Everything was working fine. then there was a crack in the fuel line. These got replaced and then the rest happened. I will take this and all yr suggestions to my man with a spanner and see what he says. Again thank you so much for all your help - so appreciate it. It's a shame that more of us don't appreciate this forum as much as. We should, until, that is, we're in deepest do-do.

Thanks again all who have responded. Oh and Happy New Year

at a guess the trigger wire to the starter motor has come off but your mechanic would have checked that first I'd have thought