C70: Electric Window Fault

[Ray Woodward]

I am new to the forum, so thanks in anticipation.

I have a window fault on my 2004 C70 2.0T Collection Convertible.

When turning the ignition key to position I, all four windows start to open automatically. They continue to open fully. When they hit the bottom, there is unpleasant juddering and accompanying noise whilst the motors try to keep opening the windows, even though they’re fully open.

It is only relieved when I turn the ignition key off, or advance it to positions II or III.

When starting the car, I have to be very nippy as I pass position I, to avoid the windows opening, even a mere fraction.

The fault also means that I have to be on full ingnition, or start up to use any accessories.

Is there an electrics wizzard out there please, who knows the answer?

[christheancient]

I am going to make a gamble of a guess.

The most important factor here is that you have a convertible. This means that windows open and shut (a little bit) so that they don't 'catch' on the roof and foul things when you open/shut doors with the windows closed.

There is a module and loads of microswitches that control all sorts of stuff for windows and roof (in the 'roof store') to make sure things don't get 'out of sync' or such.

So, you need a friend (or local friendly Volvo owner) who has the PC/VIDA/DICE setup to read what's going on. But it can get 'interesting'.

Do you have any local independent Volvo garages (I don't really 'know' Hull?) Main dealers can get expensive?

[Ray Woodward]

Thank you very much. Good advice.

I had a suspicion that there might be a connection with the hood but didn't Know where to begin looking.

I have a cracking independent garage and he’s always keen to learn and discover. The car’s going in for its service tomorrow, so I’ll pass on your tip.

Much obliged. I’ll let you know his things turn out.

Cheers,

Ray

[Ray Woodward]

Hi Chris,

Following a failed interrogation of the electronics, I am taking a punt on a replacement ECU. I have found a couple of £50 replacements on EBay, so I have acquired one.

I understand the module is located in the boot, behind the trim on the driver’s side near the rear light cluster. Two screws and four “scart” plugs.

After which, I think it needs to be programmed to my car. So back to my friendly dealer next week....

Onwards and upwards.

Ray

[PNuT]

Don't underestimate a faulty alarm siren module either!

an example would be on a phase 2 V70 they can stop the sunroof from working!

The good bit is you can remove rather than replace so a no harm experiment....

[Ray Woodward]

Thank you for the advice I received.

Sadly, an interrogation of VIDA did not disclose a resolution. So, I bit the bullet and invested in a £50 replacement ECU roof module on eBay which overcame the problem.

I read that the module could be found behind the trim on the driver’s side of the boot, near the rear light cluster. It is not immediately apparent because it is bolted to the underside on the ledge above the light, kind of hidden.

Switching new for old and plugging in is very straight forward.

It had to be programmed to talk to my vehicle though (£20 at my independent garage) and it resolved the problem immediately. One tiny hitch is that the roof closure position is very hard to reprogramme without a piece of 15 year old software. As a consequence, everything operates perfectly, until the point where the windows need to close to complete the sequence. However, by releasing the roof button for half a second and repressing it, the windows completely shut and the “roof locked ping” goes off.

Very happy and a split second, 2nd press of a button is a small price to pay to resolve everything.

Thanks again.