Independent Renault Forums banner

1 - 20 of 51 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
Hi all

Have started to get various problems with my Laguna 1.9Dci 03 estate.

After doing some research it is pointing to the UCH unit .. and it seems on these forums that as soon as anyone mentions this part no one responds to the thread ? But here goes !!

Does anyone know if this part can be opened and fixed i seem to have various problems on my car all on the passenger side.. So my questions is simple .. there must be a bad connection or dry joint or something in this unit that has failed ?? Anyone had any luck repairing them or replacing them (i know lots of other stuff needs replacing too)

Thanks in advance :confused:

This is a link to another thread i started http://www.renaultforums.co.uk/showthread.php?t=109597&highlight=central+locking - Thanks
 
D

·
Guest
Joined
·
0 Posts
As far as i'm aware, it's basically a mini ecu with a built in loom that can be coded once to a car, and thats it.
As for opening it up, worth a go i suppose! If it's dicking about you'll need a new one anyway
 

·
Premium Member
Scenic mk1ph2, RX4, ID35s11
Joined
·
5,254 Posts
hi

they can be repaired, but renault do everything they can to discourage this.

there are a few companies in the uk that do component level repair to them, as they are nothing more than mini computers with masses of I/O lines when looked at, as just about everything electrical on the car runs through them.

i have done component level repair to mine the other month, as i hooked up a wire to the wrong pin and fried/overloaded an I/O buffer.
all parts on them are surface mount, so its deffinatly not a DIY fix, i had ot use a webcam microscope on mine to double check i didnt have any short curcuits on the board after i replaced 2 chips and a resister pull up pack.
i did post a pics of the UCH in a previous post last year.

getting a spare unit as scrap for components is about £25

finding out what the I/O lines into the unit are is a pain as the only data can be found on AutoData garage diagnbostics software (silly money to buy and licence.)
if you can get the printouts then you stand a chance of knowing where to start looking to trace the relavent lines though the fusebox and back onto the UCH. (haveing a friendly garage that doesnt mind you pouring over their autodata program and print-to-file all the relavent pages really helps:d )

a new UCH is £210 from a dealership (vat is probably extra ;p) order time is 10-14 days from france special order (remmber to take all documents with you if you need to order one.)
 

·
Registered
Joined
·
9 Posts
Discussion Starter #4
Hi Thanks for the response. :)

Took out the fuse box and UCH ... Managed to find a blown diode and a lot of dampness .. picked a coupe of fuse boxes this morning from local scrap yard one from a diesel and one from a petrol .. will try replacing this before moving to the UCH ..

Thanks will post back :cool:
 

·
Registered
Joined
·
11 Posts
hi, having simular problems with my 03 clio 1.2 16v, intermitent windows, indicators, wipers and sometimes wont start, but it all has one thing in common - a rapid clicking noise coming from the uch, sounds like the click of as relay but lots of times repeated, i'm not really interested in going inside the uch, a bit out of my league i'm afraid, if i bought a new or second hand one, can i change it myself?
cheers
 

·
Premium Member
Joined
·
3,499 Posts
The UCH needs to be changed a matching set of ECU, UCH and Keycards (from a same/similar spec/same engine car) if you're not able to get a Renault dealer to program a unit...

I spent today disassembling and cleaning the fusebox and UCH in mine. I found a fair amount of corrosion and there has obviously been quite significant water ingress. However, things that I know run off the UCH work fine on my car so I don't think it's responsible for the faults. Also, things that don't run through the UCH aren't working right, so I suspect a loom/earthing fault. The UCH only had a bit of corrosion on the pins, whereas the fusebox was dreadful inside, so I might try replacing it. I also cleaned the connections on the fusebox behind the glove compartment, which was in a similar state (I'm guessing sunroof drains, but I pressure washed it today and didn't find any dampness in there, so I guess they've since been sorted.) Does anybody know whereabouts in the front footwells the earthing points are? (I know roughly where all of them are from the Haynes manual, but it's not very specific...)

I'd love to be able to afford a CLIP interface... :( I guess it's capable of testing/diagnosing UCH functionality.
 

·
Premium Member
Scenic mk1ph2, RX4, ID35s11
Joined
·
5,254 Posts
just make sure side lights are on, when u pull the battery connection.
shouldnt be any risk once car is electrically dead to rip out all those sensitive modules.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #9
I had no problem after disconnecting the UCH... But like mord says make sure you disconnect the battery first. :)
 

·
Registered
Joined
·
11 Posts
cheers guys, now say i disconnect the uch and its buggered,
what am i in for when putting a different one back in?
is a second hand one ok?
what do i need to know basically?! sorry,not clued on with this at all,
cheers again
 

·
Registered
Joined
·
11 Posts
I believe that the uch among other things controls the immobiliser. It checks that the key or card is paired to the car if the key passes this test it sends a coded message down a data wire to the ECU. If the ecu is happy with the information provided by the uch it releases the immobiliser functions. These are normally fuel pump ignition etc, this means as already been stated the key/card, UCH and ECU all have to agree that everything is OK and are matched to each other. It is possible to change a single component but usually means a recoding job with diagnostic equipment. Its to stop 'toe rags' hot wiring your car and giving the police a load of grief lol.
 

·
Registered
Joined
·
11 Posts
so if i found one from a car of my age, with same engine etc.. there's a possibility it might work?
if not, could a regular garage sort it? or would it be a renault jobby?

i also see on ebay that some people selling the uch also include the key! why is this?
cheers
 

·
Registered
Joined
·
11 Posts
I believe you need to replace the keys, uch and ech from the same car as the one you have and they have to be matched ie all of the same working car. Then I think its a replacement job otherwise the components will have to be recoded to match them up to each other. This requires sophisticated diagnostic equipment and knowledge, if you buy off ebay there is a risk that they are not from the same working car! Also the fault may not necessarily be in one of the three components replaced! I see in your original post you have random intermitant electrical faults, not sure about your particular model but there have been problems with water damage contamination. It might be worth getting the uch out and look for any signs of water!
 

·
Registered
Joined
·
11 Posts
sounds like a plan, thanks for your advice, wont be able to look at it for a while, but will post with updates as i go,
thanks again
 

·
Registered
Joined
·
6 Posts
Can the UCH be removed and the same unit put back in, without losing important settings? i.e. will the engine still start etc?
The Haynes manual says that if the Multi Timer unit, which I think is another name for the UCH, is removed it will lose settings, and may prevent the engine starting.

hi

they can be repaired, but renault do everything they can to discourage this.

there are a few companies in the uk that do component level repair to them, as they are nothing more than mini computers with masses of I/O lines when looked at, as just about everything electrical on the car runs through them.

i have done component level repair to mine the other month, as i hooked up a wire to the wrong pin and fried/overloaded an I/O buffer.
all parts on them are surface mount, so its deffinatly not a DIY fix, i had ot use a webcam microscope on mine to double check i didnt have any short curcuits on the board after i replaced 2 chips and a resister pull up pack.
i did post a pics of the UCH in a previous post last year.

getting a spare unit as scrap for components is about £25

finding out what the I/O lines into the unit are is a pain as the only data can be found on AutoData garage diagnbostics software (silly money to buy and licence.)
if you can get the printouts then you stand a chance of knowing where to start looking to trace the relavent lines though the fusebox and back onto the UCH. (haveing a friendly garage that doesnt mind you pouring over their autodata program and print-to-file all the relavent pages really helps:d )

a new UCH is £210 from a dealership (vat is probably extra ;p) order time is 10-14 days from france special order (remmber to take all documents with you if you need to order one.)
 

·
Premium Member
Joined
·
3,499 Posts
Can the UCH be removed and the same unit put back in, without losing important settings? i.e. will the engine still start etc?
The Haynes manual says that if the Multi Timer unit, which I think is another name for the UCH, is removed it will lose settings, and may prevent the engine starting.
Nonsense, I read that in the Haynes manual and had a near-heart-attack, but it's not a problem at all... Otherwise, just disconnecting the battery would kill it!

You can get it out without removing any of the dash - it's a bit of challenge with the number of things that are plugged into the fusebox and requires extensive 'manipulation' but this is how Renault say to do it themselves, anyway.
 

·
Premium Member
Joined
·
2,861 Posts
My front windows aren't working and I reckon its the uch. Is it not unusual to only have one function go and not the whole lot?

Would hate to get bummed by renault and buy a 200£ part that does nothing for the problem :cool:
 

·
Registered
Joined
·
16 Posts
I'm having problems with the rear wipers and front foglights on my 2001 Clio. My local garage said that this is probably the UCH and that they couldn't replace it as it would need to be programmed. My local Renault garage has just quoted to replace and re-program would cost in the region of £500! Will learn to live without the rear wiper and front foglights!:eek:

Jassyblue
 

·
Premium Member
Joined
·
431 Posts
My front windows aren't working and I reckon its the uch. Is it not unusual to only have one function go and not the whole lot?

Would hate to get bummed by renault and buy a 200£ part that does nothing for the problem :cool:
It could be argued that your two front windows are two functions, not one. And that then changes the focus to some other common mode failure that might affect both functions. (Damage to just these two parts of the UCH is unlikely, without something expressly causing it, as the actual circuitry would have nothing else in common)
Do your rear windows still work?
Anything else that relies on ignition, etc? Like the speed of internal light dimming?

If you get other (internal) functions to work, then the power and ignition signals are reaching the UCH, and you might then need to check the fuses and power at each stage down-stream. (Not forgetting issues at the control buttons, which might be focussed on the driver's door, where the two systems also converge. Or even the harness for the driver's door, with it's convenient connector in the exposed area near the hinge).

I'm still hypothesising about system diagrams, but most of the relevant issues are either obvious (like switches, motors and fuses) or assumed good (like harnesses, bonding paths, and lack of corrosion in the UCH). Fortunately, most electronics nowadays can survive disconnecting the load (broken wire) without frying the driver. (That's the power driver circuit, not the nut behind the wheel ;) )
 
1 - 20 of 51 Posts
Top