Hello - I have a problem with my 2011 Yeti - all working fine until didn't start one morning.

 

Turns out the ECU fuse was blown - the garage came out and replaced it and things were fine for a day or so. But this morning it blew again and is now blowing immediately on turning over the engine. I understand it could be any number of things triggering it - my local garage didn't think they would be able to diagnose and fix the issue. 

 

Has anyone has a similar issue? Or advice on how to go about diagnosing/fixing (in South London)? 

 

Thanks!

I think you’ll need to expand on exactly which particular version of Yeti yours is if you want a response.

Thanks, its a 2.0 SE TDI CR 4X4 S-A

Which number fuse is blowing?

F13

A 30 amp fuse takes quite a bit of blowing. Inspect the area for water ingress?

Hmm, we’ll there is a 20 in there at the moment...so that might be a cause. I’ve looked around for a diagram showing amperage/fuse number but no joy. 

One way to get fuse info is to buy an hour's access to erWin Skoda for around a tenner, and find it on there.

As far as I can see, that fuse should be 20A 15A for petrol engines, 30A for diesels, so maybe that's all there is to it? Stick a 30 amp one in there and see if the problem goes away.

 

Edited 25 January, 20197 yr by Wino

Ok, with some inspection in daylight, I now realise it’s fuse F14 which is the ignition (which I think should be a 20), so I guess something more than incorrect fuses. 

On diesels, fuse 14 is:

"Fuel pressure regulating valve -N276- , Fuel metering valve

-N290- (vehicles with diesel engine)"

 

Do you know your engine code? It'll be on the boot-floor car data sticker. That would guide me to the exact spot in the circuit diagrams showing these things.

Think it is ‘CFHC’ does that sound right?

Can be yep. That fuse appears to power just those two valves.

A black/red wire comes off the fuse to a 14-way connector "front left in engine compartment" (UK nearside), where it changes to a blue/red wire which splits at some point into two blue/red wires, going to pin 2 of each of those valves mentioned above. The pin 1's go to a 60-way connector at the engine ECU, pin numbers 45 for N276 (green/black wire), and 60 for N290 (blue/black wire).

 

'Fraid I don't know where those valves are in your engine bay, but I'd imagine one of the wires above may be shorting out, or water may have got into one of their connectors, possibly.

Edited 26 January, 20197 yr by Wino

Thanks, that’s really helpful, do you think it’s likely to be the connectors or a fault with the valves or wider fuel system? I guess hard to say without having a look!?

VCDS scan may help (with a new fuse fitted) as it may be able to tell you which of the two valves the ECU thinks is faulty (or it may suggest both, which would point to wiring upstream toward the fuse).

Visual inspection of as much wiring as poss, and all the connectors mentioned would probably be my other suggestion.

Personally I'd start with tracing the wiring and checking all the wires and connectors, this is cheap as it costs nothing more than an hour or so of your time.  If you don't find anything with the wiring and don't have access to vcds it's probably a garage job for a VAG specialist or skoda dealer.  it may require swapping out the valves one at a time with known good examples.

 

From a quick google I found this diagram for an Audi A3 diesel which might help you trace things.  Ok, not a Yeti, but I expect it'll be close enough to give you a good clue where to look.  I doubt they'll change things that radically from one engine or manufacturer to the other.  N290 is number 24 on the top diagram and N276 is number 8.  There's another diagram about half way down the page that gives a slightly better view.  From that it appears the N290 valve is on the front facing side of the engine fairly low down, so it may be more prone to water ingress or corrosion damage than the other one which seems higher up on top of the engine itself.

 

Edit: Also found this diagram on that page, number 5 is the N276 valve.

 

 

Edited 27 January, 20197 yr by widdershins
More info

Thanks very much widdershins and wino, really grateful for extremely helpful advice. I’ve had a good look at the connectors and wires and can’t see anything obvious, so off to a different local garage, unless anyone has any recommendations in south east London...?

You could probably find someone suitable by looking through another section of the forums. Skoda dealers and independent garages in London

Finally resolved this - turns out part of the wiring harness was rubbing between the engine and chassis deep in the engine bay somewhere. A & A Auto Electrical in Croydon sorted it. Would recommend. Thanks to those here for advice. 

 

If you were happy with their services you could give them a review in the London garages section I linked to above.  That way anyone else looking for an auto electrician in that area will find your comments more easily if looking for someone decent to go to.