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Hi Guys, I have a problem with the front NS headlamp. When I switch the lights on with the engine running the NSF headlamp goes out but if I switch them on before starting the engine it stays illuminated. someone told me that it could be down to corroded pins in the UEC or dampness. Do you agree and should I clean THE UEC AND REPLACE????

Please Help

Any suggestions would be grateful

Cheers
 

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Nothing to lose by cleaning the UHEC , it may well cure your problem .
 

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Hi,

Can this issue cause intermittent starting problems? roughly once every 10 starts the car won't turn over and sometimes you can hear the starter motor clicking/spinning hesitantly.
 

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I need to remove UEC, I unscrewed all torx bolts, but UEC seems connected to one of three plugs below and I can't pull it off. Did not want to use excessive force. What's correct procedure for UEC removal? Do I need to push bolts to disconnect connectors below?
 

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Hi,

Can this issue cause intermittent starting problems? roughly once every 10 starts the car won't turn over and sometimes you can hear the starter motor clicking/spinning hesitantly.
Could be a wiring issue.
 

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I need to remove UEC, I unscrewed all torx bolts, but UEC seems connected to one of three plugs below and I can't pull it off. Did not want to use excessive force. What's correct procedure for UEC removal? Do I need to push bolts to disconnect connectors below?
Yes, sometimes the plugs stick inside the bottom of the fuse box, pushing down on the screws will release the plugs.
 

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Just wanted to add if your UEC main board is too far gone with water damage you do have the option of a transplant. This avoids the need to find a compatible reset UEC and the associated programming resulting in a much cheaper repair.

Quick disclaimer, this is how I did it and offering this information as a guide only. Be prepared for a full costly replacement if you get this wrong and don't blame me please.

This is my UEC and the coded module paired to my car lives under that long cover with the 'GU' white sticker on it. I noticed the mainboards however share the same code and highlight this in the image below (>PA6...)



In theory you're meant to be able to remove that long cover and then release the coded module and that would be easy. Job done.

However the connector is so tight on the coded module and you need to pull it up to release. You can't do this without causing damage to the components on that delicate module and there is nothing to grab hold of. I worked out it would be safer to push up on the modules circuit board from the bottom. The catch 22 situation is that the UEC board only comes apart properly with that coded module removed so I had to break my UEC mainboard.

First job take a photo so you know where everything goes and remove all relays and fuses laying them out to make re-assembly easier.

Then remove the main screws, the retainers can be bent with a micro screwdriver and removed. The small little screws on the top side also need removing which are already removed in the picture above, watch out of the partly hidden one where the coded module cover rests slightly on it (push cover and unscrew it will come out).



Carefully break the plastic in this location with cutters and pliers and remove that nut.



The bottom case will remove now by carefully pushing some of the bigger metal contacts. There are some green pins that have four wedges and it looks like I pushed them down in the photos above. I can't remember if that was a required step of if they are only locating pins. Keep that in mind if the lower case is not budging and try pushing them down or up.

Now to remove the coded module cover it has a tab on each end that will release with a Jewelers screwdriver. Not the best photo but push the tab into the center and it will release that side of the cover.



Now I could rest the all important coded module on the cardboard and apply pressure all along the edge of the circuit board. There are two retaining tabs that you jam free with the aid of two jewelers screwdrivers then I could push down on the main board to free the module. It requires a fair bit of force to fee which is why I couldn't just remove the cover and pull that board up.



There it is the coded module free from my UEC and the donor sneaking into picture (more on that shortly).



Just for interest now with the coded module removed you can see the top separates and how you would get to that nut the proper way if life was easy :)



With your coded module ready for it's new home you need to prep the donor UEC. As you don't need the donor coded module or it's cover we can sacrifice those components to get us a blank UEC mainboard.

To remove the coded module cover, slide a thin plastic card in from each end to push those tabs in and release. Alternatively since we are not using the cover get some wide pliers pulling up and push the ends in and the cover will pop off. As the donor coded module is useless you can grab it with pliers pulling upwards and two jewelers screwdrivers in the release tabs.

Photo showing the donor with it's coded module and cover now removed.



Push your original coded module into the donor and it clicks into position. Attached the original cover and then check all fuses and relays are in the correct position and ratings compared to your original UEC picture.



Done... One transplanted UEC.


Do this entirely at your own risk and as a last resort.

I did this last year and gone from memory so please us this as a guide and I will try and include more detail if I ever do one again.

This info might help someone and I promised these photos in another thread.
 

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For those that are interested, this is how you remove and clean the UEC (Underhood Electrical Centre), with photos, on an Astra H and Zafira B. This is worth checking when you get Throttle Pedal Fault Codes or other weird Codes. The UEC is prone to getting water in it and can cause all sorts of problems.

UEC is located under fuse box, the plastic cover unlocks easily using a screwdriver in the red circled area, but first make sure you disconnect your battery first.
Then unscrew the three silver torx screws.
Unlock the two plastic lockers (one either end) and unscrew the 10mm nut.
Simply Lift out the fuse board top and underneath you will see a lot of pin connectors.
In my case I found water droplets in the rubber (look inside red circles). Water was clearly visible but check everywhere on it as water or damp could be anywhere.
Cleaned and sprayed Electrical Contact Cleaner over it. Do NOT use WD40.
Also check the underside of the Fuse Board (top part you took off). Remove any rust on the pins with fine emery paper, clean and spray, leave to dry then put everything back together.


Also bear in mind that you may not actually see water but it may well be damp and can still cause problems. So while its off its still worthwhile clleaning it, wiping it and spraying it with electrical contact cleaner (NOT WD40). Its actually worthwile taking it into somewhere warm and leaving it near a radiator overnight so its completly dry when you put it back together.

On a side note, I think I know how the water gets to the UEC. Some of it will come in between the radiator and light as you drive but I dont think thats the biggest issue. I noticed that if the car has been sat in rain and the bonnet is covered in water or you have just washed it, if you open the bonnet a lot of water drips off the front lip of the bonnet and hits the corner of the battery, it then bounces and splashes on to the front corner of the UEC next to the battery. Just something to be wary of if you open the bonnet and its wet. I usually lift it about 6 inches and wipe the front lip with a cloth or just my hand to stop it dripping.
.
Thanks smokie1010, this was really helpful, shame photobucket have ruined their image hosting so the pictures don't show anymore unless you pay $300 a year.
The only bit I couldn't work out without the pictures is the 10mm nut. If anyone else comes across this post, the 10mm nut is in the top left corner of the fusebox as you look from the front of the car and it is outside the fusebox, if you are short like me you need to lean over the bonnet to see it :)
 

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I followed Speedy's guide above as I had to replace the fuse box. No amount of cleaning was going to solve my problem!

Once it was taken apart I could see metal tracks burnt out and corroded due to water getting into the fuse box. With tell-tale patches of white and green on the underside of the board. The fuse box cover was properly fastened, so I've got no idea how water had made its way into the unit. Reading forums and YouTube videos this seems like a common fault though, people even having issues after having their car washed!

I followed the guide pretty much step for step.

Can confirm that there's no way the coded module can be removed without damaging it by just removing the top plastic cover. It has to pushed upward from the underside just as Speedy has said. I did try on the Ebay replacement part. Ended up damaging the board by taking off a SMC chip while trying to wrestle with it. But being as the Ebay donor board was going to be binned anyway it didn't really matter.

I had to remove quite a bit more of the plastic cover so that I could get a drill head on to the nut, as after much swearing the nut just wouldn't budge with a spanner.

I also found it easier to remove the coded module (once the cover was removed) with a couple of credit cards jammed into the retaining slots instead of using jeweller’s screw drivers, so that technique may help someone else.

The coded unit did require quite a bit of upward force to remove even once it had been taken apart. Pushing board upwards just wiggle right side then left side till it starts moving. Being careful not to damage the board.

Once the coded module was removed I transplanted it into a donor fuse box I bought on Ebay

I re-attached the fuse box, re-connected the battery, turned the key apprehensively.... and to my surprise it actually worked!

Huge thanks to Speedy who re-uploaded the images, and answered my Nooby questions. Couldn't have done it without you mate
(y)(y)(y)(y)
 

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Hi all,

I know this is an old thread but thought I'd contribute as this guide has helped me, too many people are quick to find a guide fix the issue and never feedback so the next person to have the issue can't fix it straight off the bat, that can be frustrating.

My issue was, my 06 Zafira B started having trouble with the drivers side brake/stop bulb after defrosting her in this weather, the bulb would come on bright then flicker for about 3-4 seconds and shut off.

Also through Op Com recording DTC - B3878 Rear right brake light malfunction

Leaving only my strip and left bulb working

I followed the guide and removed the front fuse box, no water moister in there, but still cleaned it out using WD40 contact/electrical cleaner (Screwfix was the cheapest)
Just a tip for removing the front box is be patient, as you wiggle the box to remove it I fount the securing tabs kept clicking back into place, so just take your time.

Anyway, I left the front to dry off and went to check the second fuse box in the boot of the car, all seemed OK until I pulled the plugs from the main board, the top left plug (Blue iirc) was full of actual water, and oxidisation on some of the pins in the plug itself, I shook the plug a few times to get as much as I could of the water out, then sprayed in some contact cleaner, as for the greenish looking pin's very gently with a sowing needle removed it as best as I could without causing any actual damage

All the other attached plugs were fine and dry but still cleaned and sprayed them either way.

After letting the plugs dry off, I reattached them and sprayed all of the board to give it a clean and to protect it from further moister getting in.

I then re assembled the front fuse box, again taking my time, reconnected the battery, and let the car run for about 10-15 minutes before trying the lights as I wanted the ecu's to relearn everything that had been reset rather than starting it and whizzing off for a spin potentially learning false information.

Tried the light's again and they worked spot on!! I have fixed an issue without causing any, so job done and really pleased with the outcome

Big thanks to Speedy for this useful guide (y)(y)

Just though I'd share my experience in case it helps somebody else down the line, as at first I thought it was the bulb or the bulb holder itself playing up.
 

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Dave D86
Thanks for this - I had a similar problem and did the same as you with the front fusebox
(I’ve got an 07 Astra TwinTop)
I didn’t do the back fuses - so I’ll look at that today. But when you talk about the “top left Plug - blue iirc” that doesn’t sound the same as mine. Don’t suppose you have a pic to be clear which one it was do you?
cheers
 

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Hello guys,

If someone can please answer my question it would be great... I just want to know does the UEC link to the gearbox shifter somehow because I have a AUTOMATIC zafira b and the gearbox shifter does not recognise when I press the brake pedal as it wont let me get out of PARK. If I turn the ignition I can select another gear fine and when I start the car it will still let me drive and choose other gears fine. Its only if I start the car up in PARK, it wont let me shift into other gears. The reason why I think it is the UEC because I came out and my passenger dipped light was turned on, I got in the car to find the switch was on 0 so I didnt intentionally turn the light on, it just came on by itself. My brake lights are always staying on as well but they will work fine if I leave key in ignition but dont start the car up, brake lights work but if I start the car the brake lights stay on as if im pressing the brakes. I checked with DELPHI computer software and it shows a bunch of codes main 1 being "NO COMMUNICATION TO UEC".

I already removed the fuse box, cleaned it up, I admit I did use WD40 not electrical connector, but I put isopropyl alcohol at the end to clean any residue off, The passenger light went off and now works only when I turn the switch however my brake light still stays on and the gearbox doesnt want to shift into any gears if car is left in PARK and started up. Gear selector will work fine if I put into NEUTRAL before I start the car.. and yes there was some small water drops in the pins of the fusebox... Could it be that the fusebox is damaged to the point it is not repairable and need to replace it? or should I take a look at the REC as I have that in the boot too?

I guess my question is does the UEC control the gearbox shifter or the brake lights as if it does then maybe I can pull the fuses and put some electrical connector in those areas specifically and hopefully get it working again. Cant see on the online diagrams if the UEC controls the gearbox shifter.

Thanks.
 
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