Hi

I've been having a lot of random fault codes appear (all power train) intermittantly on my Octavia 1.9TDi Elegance. The car has also been having some intermittant power issues but note that there has never been a boost related DTC so I'm assuming for the moment that the turbo vanes are not sooted up.

All the codes have a theme which is 'short to earth' or 'short to B+' so I'm thinking along the lines of a wiring fault / loose connector etc. Having read the Haynes manual (sorry) there is a specific warning regarding disconnecting the ECU in that it claims all the standard values have to be re-set by a Skoda dealer. Basically I just want to take the connectors off the ECU and give them a clean with contact cleaner, does anybody know if doing this will require a dealer re-set ?

I have VAG COM / VCDS lite which is how I have gained access to and interpreted the codes, I'd also like to know if anybody has experience in using this to re-set the ECU standard values or indeed if this is possible on the lite version.

Oh and finally, if anybody knows of any famous weaknesses in the Octavia wiring loom please let me know as this is very frustrating.

Thanks in advance for any help you can give me...

Michelle

Having read the Haynes manual (sorry) there is a specific warning regarding disconnecting the ECU in that it claims all the standard values have to be re-set by a Skoda dealer.

That's total rubbish, don't worry, you're perfectly safe

Thanks alot for that Shark, makes me feel more comfortable doing it now!

Can I ask, in your opinion, does it sound about right that I've got some kind of problem with the connections?

Appreciate the help, I just want ma beast (aye yep thats her name lol) back to best, putting ma foot down just isn't the same at the mo

Michelle

It's certainly possible yes, I'd recommend using some silicone grease in the plugs, you can buy it from Maplin

Might be worth looking at the power supply to the ECU, it is powered through the 109 relay which is known to be problematic, might be worth a new relay for the small outlay.

Relay is mounted in the relay plate which is behind the trim under the dash on the drivers side.

Thanks Tech1e, another avenue to explore.

At least its not the turbo as initially thought as thats where this started with, loosing power when putting my foot down up hill.

The latest appears to be a fault with the ECT light, hence why i'm now going with a wiring issue.

Appreciate the help and really should start watching this forums more!

Michelle

+1 for Relay 109 (replacement is £15-£20).

I'd clear the codes and see if the same codes come back. If different codes come back each time then it is almost certainly relay 109.

Right I'm now wracking my brains to think if I've had the same fault codes come across.

I know this is the first time the ECT faults come up, I've also had MAF faults along with others. I really should have written them down but this has been ongoing since July.

Now i'm praying for it not to rain too much on saturday so I can start checking this out

Michelle

Take a look at post #15 in thread http://briskoda.net/forums/topic/177453-leaking-rear-washer-pipe-might-have-caused-electrical-damage/

It's a different problem, but it shows the relay plate and how to get to it

Thanks for that rwbaldwin, will let you all know how i get on!

also a good place to check is the earth wires down on the chassis leg by the battery, they do corrode up and go green which can/does cause airflow meter faults along with other ones

Well I managed to get a look at her yesterday and think its a case of one step forward, two back!

I checked the earth wires on the chassis and they're sound.

Checking the 109 relay was more interesting, the relay looks sound but when it plugs back in it's definately not as tight a fit as the other relays, so that'll be the dash coming out to check the connectors behind that when I have another dry day!

As for the short on the ECT, found the sensor and hmmmmm that wirings not looking top notch so another one to look at again when I can get to it :S

Thank god I can have a go at this myself, dread to think how much a garage would've charged trying to find this.