My son's Fabia 2 front wipers don't operate. Fuses (44, 40, 15) are OK.

 

I've got wiper arms off ready to remove mechanism and check motor, but before going further I wanted to test the motor from the onboard power module that sits above the throttle pedal.

 

It's quite a contortion to get your hand onto the wiper plug, and there's some kind of catch on side of plug. I can't get in position to put decent pressure on the catch or get the plug to detach.

 

Any tips for getting the plug off please so I can power motor while it's in situ? Failing that is it possible to remove the module to get it in better position to remove plug? It's not obvious visually how the module is attached to underside of dash.

 

Thanks a lot!

The latch pushes inward to release, towards the main bit of the connector, from memory.

May take a fair pull to disconnect though.

 

You could probably do it with plug in though,  just by poking a paperclip or similar in the cable entries of the relevant pins to short them, bypassing the relay.

Edited 16 October, 20214 yr by Wino

bcm module clips into the holder and when released it drops down, but does not hang to low with all the wiring still connected.

 

It would be easier initially to see if there is 12v at the motor when the switch / stalk is on

 

do the wipers go when using the screen washers ?

 

What year is the Fabia ?

Edited 16 October, 20214 yr by UrbanPanzer

Thanks both.

 

It's a 2007 Fabia (or maybe model year 2008 but on a 57 plate). The wipers don't go with screen washers.

 

In absence of progress with the module I disconnected the motor. There is 7.5V all the time at the pin next to ground (maybe something to do with park circuit?) but 0V at pin 3 and pin 4 in the slow and fast stalk positions). The entire motor and linkage mechanism works smoothly when powered directly with 12V at the pin 3 or pin 4 connections on the motor. I only hear a click (relay on power module presumably?) in the fast stalk position.

 

I've now replaced the wiper mechanism, arms etc as that's all fine. Looking likely that there's fault in power module, unless there's a way to test stalk switch? Can it completely fail with no power to wipers in intermittent, slow or fast positions?

 

Out of interest, check fuse 26 as well.

Thanks for suggestion UrbanPanzer but fuse 26 is good (mysteriously the icon for it on fusebox legend is an open book with exclamation mark).

 

Once I can remove the power module I think best bet for avoiding any incompatibilities is to replace wiper replay on the board. That relay seems available only in China (Minitools in Italy has it but have €150 minimum order for private buyers) and will take ages to get here, so I may try a used 6Q1937049F module and scavenge relay from the replacement module. Will check it first as straight swap to see if any issues arise with memory/data.

I'm pretty sure I've got a spare relay I could send you; or as you're not a huge distance away I could fit one to the original unit here 'while you wait' (or by post) if you wanted, for a small consideration. 

 

Easier to just swap in another whole unit though. If you can get the coding of the current one via a VCDS autoscan, then just poke that into the replacement unit once fitted.

 

 

That’s a wonderful offer Wino! If you let me know how much you’d like for the relay then I’ll buy that from you - am pretty handy with electronics so installing it won’t be a problem (famous last words). Just let me know how to sort payment or can pick it up if you’re reasonably close (I’m in Warwickshire).

 

Thank you!

I'm near Abingdon, Oxon; so posting seems the obvious way of getting it to you, if you PM me a delivery address we can discuss payment there. 

This is the one I've got. Probably a good plan to check that this is what's in your current unit before we go too far. 

 

That’s same relay I’ve seen used in other Fabia 2 and Polo but please see PM - no probs if turns out to be different.

Well I'm snookered on this job. I got hold of a used voltage control module cheap just so I could see how all the plugs and catches worked. If I had the faulty one out the car it would be simple to solder in a new wiper relay.

 

But the way the module sits under the dash makes it impossible to get my hand in at an angle where I can release the catches and remove the lower plugs. According to the manual this will then allow the module to drop down further after releasing catches, so you can release the upper row of connectors.

 

If I release the catches with all connectors attached, there's not much movement with looms attached, so you can't get the module into a better position for getting a hand on the plugs. It's literally Catch-22!

 

Honestly who designs these things?

Edited 23 October, 20214 yr by Stratfordade

Awkward stuff in footwell areas can sometimes be made much easier by removing the front seat, so you can get into more favourable positions. 

4 XZN-head screws and maybe a connector under it and out it comes.

That was the only possibility that I thought of Wino, so worth a try.

 

Thanks again for sending relay. On the old board I bought there are another two which both test OK, so at least I'm not short of relays!

Good call Wino, with seat out I could get enough purchase to remove the module.

 

The good news is that I did verify that the relay is faulty. Both coils are ok but only one of the relays switches. Also the two switch poles which should be isolated are shorted together.

 

The bad news is that they changed the relay type going from the 6Q1937049D module to the 6Q1937049F which is the one in Fabia 2. Instead of the Tyco relay there's an Omron G8NW-2U with same functionality but different pin outs. I've located a UK source for the relay but for time being the car will be out of action. I could plug the module back in and reinstall the seat but it's such a pain getting the module out (despite better angle my fingers still very sore!) I don't fancy repeat performance.

Oh, that's a bummer. Worth fitting the spare you bought and hoping it was coded close enough in its previous life such that everything works?

Return the relay for a refund, by all means. 

Edited 23 October, 20214 yr by Wino

Thanks but wouldn’t dream of returning it - said I’d take risk!

 

I’d put in the old board if it was same part number, but since they differ (C suffix v F suffix in my son’s car) I’ll just wait for correct relay, and also not have any problems with different data etc. Ironic as it looks like only component change on the board is that relay (also used for rear wipe in place of Tyco one on the older board).

All's well that ends well. I've got the faulty relay off the voltage control board ready for new one, but that won't be here for couple of weeks.

 

Meantime I got hold of a used same generation board as in the car (6Q1937049F) and that functions perfectly and the car has its wipers back (I confirmed that the wiper relay on the used board operates both switches, whereas the faulty one has a failed switch on one side). I'm not sure what data would be on that board that would cause a problem, given that it just seems to do all the switching for circuits controlled from dash and wiper stalks.

 

The only problem is that the airbag light stays on, but I have researched this problem and other people have experienced this when they've pulled front and rear wiper fuses to test them. Somehow it interrupts the airbag circuitry and it doesn't reset even if you replace the fuse. I'll need to find someone local who can reset it, assuming I didn't do anything more drastic removing and reinserting all the control board plugs!

43 minutes ago, Stratfordade said:

I'm not sure what data would be on that board that would cause a problem

More configuration than data.

If the car it came from had all the same options, it's probably been coded identically, but if  not there might be some functional anomalies.

This page shows (as an example that may not be exactly comparable) the coding options for a 9N Polo, you get the coding by adding together all the numbers for each of the fitted bits of kit.

VW Polo (9N) Central Electronics - Ross-Tech Wiki

VCDS Lite ought to be adequate for recoding, and for clearing the airbag fault AFAIK, as recently confirmed a few threads down from this one:

https://www.briskoda.net/forums/topic/498514-anyone-use-vcds-lite-on-their-early-mk2/

 

But I guess you don't know how the original unit was/is coded, unless you have a historical VCDS autoscan saved somewhere?

I'll try to find the equivalent coding table for your car when I get a chance. 

If everything you expect to work works, there's probably no need to do anything pending relay arrival.

Thanks Wino that's very interesting. The car is not highly specced (no heated front screen/mirrors, trailer hitch, headlight washers,  cruise etc) so not surprising that it seems happy with the replacement module. I just checked the remote hatch opening and that's OK too.

 

Will keep monitoring and get the airbag light sorted.

 

Thanks for all your help on this project.

Also thanks for all your info on VCDS-lite. I’ve got it running fine on ancient netbook (I’m all Mac and use the XP machine exclusively for Porsche parts catalogue), and have lead ordered from Gendan.

 

My son’s Fabia 1.4 is BXW engine btw.

if you unplugged the seat belt tensioner (when removing seat) with the battery connected, thats why you have the airbag light on, VCDS will turn that off no probs.

Edited 29 October, 20214 yr by UrbanPanzer

Ah, good shout! Or seat airbag?

Thanks UrbanPanzer. I unplugged the seat connector with battery disconnected, but I did reconnect battery with seat unplugged in order to lock car.

 

Don't think seat has an airbag. I don't know whether the single connector I unplugged was just for seatbelt monitor, or for belt pretensioner as well. Don't know if there is pretensioner, but the seat definitely has no side airbag. It's possible I didn't fully reconnect the plug, so I can unbolt seat again and double check if VCDS doesn't do trick.

Edited 29 October, 20214 yr by Stratfordade

It definitely has a belt pretensioner.