Renault Clio UCH (fusebox) repair - Page 1
Forum section: electronics / repair

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: February 15, 2017, 04:39:26 pm
content: This is a bit of a long story, but I will try to keep it brief. The problem started with dipped beam headlights getting stuck on. This was traced to the relay which was swapped with the one in the foglight. Now the dipped beam light worked as it should. The problem started when I sourced a replacement part from Renault. First, it had 5 pins instead of 4 and didn't fit - there were only 4 holes in the fuseboard. I was assured it is the correct part and advised to snip one of the pins. I was very careful and did a very neat job of that. With said pin removed the relay now fits into the slot, but no headlights. Put the old foglight relay back - still no headlights. here is where the problems really began.Upon further investigation, the old relays do not have a diode across the energizing coil. The new one does. The polarity of the 2 pins to the energizing coil was the wrong way around so the diode presents a short.Now starts a bit of a story with Renault because they insist the part is correct and that I was given the correct advice. They blame 'burned contacts'. There is some plastic melt under the relay as the old one got rather hot, but the contacts are OK. Escalated to branch manager, then to customer services at HQ, but with no success. Quoted 412GBP +VAT for replacement and programming of UCH. My view is that since they gave me incorrect advice (although be it their parts representative was following what it said on the computer) they should deal with the consequences of that advice and repair the fault it caused.Shorting the switch contacts turns on both headlights which confirms that those contacts and the bulbs are also OK.Regarding the relay energizing contacts, I have about 13v on one side and 5v on the other. That 5v seems to be a rather odd reading. My suspicion is that the driver transistor has failed due to overload.Since I'm stuck with dealing with it on my own, I removed and opened the fusebox today. There is a main PCB and a daughterboard containing electronics and the processor. I traced from the contacts - which are all fine - back to the PCB but unfortunately this appears to track to the underside and removing the daughterboard requires de-soldering some 32 pins. If they are soldered using lead-free solder then that will present a major problem.The transistors topside all have 'XF' on them and are marked Q?? rather than D??, but according to the SMD catalogue, XF refers to a diode? I am still a novice with SMD reworking and I have practiced removing parts on an old PCB, but I am a little apprehensive about overheating something and causing further damage to that processor PCB.What would members advise? Bite the bullet on the repair cost? Attempt it myself? What does the XF stand for on that three legged part? Even if I were to consider replacing that transistor, what is the chance that the control logic for that line on the processor is also damaged? Is it worthwhile referring the matter to the Motor Ombusdman?PS - image of processor PCB added.

author: wictor
author_rank: Regular Contributor
timestamp: February 15, 2017, 06:10:34 pm
content: Hi,image of the PCB would help a lot of idenfiying components. Transistors are often marked with Qxx, so that's fine. Do you have a multimeter? That would be good for checking whether the transistor is bad.Wictor

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: February 15, 2017, 06:23:23 pm
content: Wiktor, I have added an image of the processor PCB. Yes I do have a decent multi-meter. As I mentioned, the transistor is underneath. It doesn't track to the ones on top unfortunately.

author: Christopher
author_rank: Frequent Contributor
timestamp: February 15, 2017, 07:06:49 pm
content: Fix yourself -- definitely just a blown transistor.I've had nothing but trouble with ombudsmans/car repair companies!Whip that top board off and take a pic of the PCB below. Use some leaded solder and heat up all the pins.Or send it my way and I will fix for you for a small $

author: wictor
author_rank: Regular Contributor
timestamp: February 15, 2017, 08:17:18 pm
content: Hi,I can't see the component in the image properly, but here is one with xf marking:http://www.1688eric.com/en/product.aspx?id=352645orhttp://www.s-manuals.com/smd/xfJust measure those transistors/mosfets in the ohms range. Quite often they are just shorted or totally open.

author: valere
author_rank: Contributor
timestamp: February 16, 2017, 12:19:16 am
content: Hi,Regarding the choice of components part to fix cars electronic. The car repair employee of a small car repairing company was searching for a filtering (between electrical motor terminals) capacitor to fix an electric hydraulic pump (Citroën magic "wouhhouu" suspension), the official fully new part 600€ !! The same capacitor from Alibaba (2€ for 50 or something like that and 30 days delay), and... well there we are it didn't burn because of a fault, it burned because it was a piece of "bullshit", replaced with the same voltage, same capacity, adapted temp rating and technology from RS (something like 2€ for 2 ou 5), a bit bigger still fitted perfectly (chosen by me for that), most likely the new part will last forever with a ten or twenty times bigger life expectancy... To get a 1-cent economy they put a damned under quality capacitors for a high-end car part... wouin wouin.-TransistorSo, if you don't manage to find the exact same transistor, you could probably analyze a bit the circuit, draw part of the schematic and probe some tensions and then you will find a suitable one for replacement, and you will most probably put a better one(it may require to reverse engineer a small part of the circuit to be sure).For example, most likely it's a mosfet (probably N) or maybe bipolar (probably NPN). If you dig a little, you will find a pull-down resistor on gate MOSFET which will not be here if it's a bipolar, and bipolar will have a resistor in series on base, mosfet may or may not have (not needed but protect the uC in case of something wrong), so find +VCC, GND, track to uC (micro controller), and I think you will manage to find and understand how it's designed(personally I learn so much that way)-SMD ReworkAbout the SMD rework, don't be afraid of a small three-pin transistor like that it would be okay, if you have access to a decent hot air station, you can get yourself some kapton tape (or aluminum foil) to protect around, it really helps a lot, be gentle use a small screw driver and thus put its weight and your finger on its top, when it's hot enough the transistor will just slide gently without damaging traces, and since you trained on an old board you will manage it perfectly.-uC lineFirst guess, I think it's very unlikely the micro controller output line is damaged.

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: February 16, 2017, 11:52:24 am
content: Thanks for the helpful replies!Quote from: Christopher on February 15, 2017, 07:06:49 pmI've had a conversation with Citizens Advice today and although they will pass the details to Trading Standards who may or may not take it up, basically the burden of proof falls on me. So to build a case I would need to provide evidence that a court would accept as proof that this relay they sold me was the wrong part for that particular function. I am not sure at this point who might be able to offer such expert advice or what it might cost or how viable this would be. I still get the feeling that it would be easier and a lot less hassle to just fix it myself or pay someone to do it.Quote from: wictor on February 15, 2017, 08:17:18 pmThe first one looks like the part, but then the second link has three different XF references that refer to quite different parts - a diode, a MOSFET and a standard transistor. Confusing! Given the application it is most likely a MOSFET as per the first link.Quote from: valere on February 16, 2017, 12:19:16 amKapton Tape! I have seen video's mentioning heat resistant tape but I couldn't find the right stuff. A search on 'Kapton Tape' brings it up and can now order some. Thanks for mentioning it by its name.I used a set of ordinary tweezers although these were a little too pliable but I seemed to manage OK. I had some proper SMD rework ones on order from China and these came the other day. On the old board I had an adjacent capacitor rupture due to the heat so I was a bit wary, but I was able to remove various transistors and even ICs without any physical damage. Hopefully once I can prevent this as shown on the video by masking with the Kapton tape.Regarding the heat setting on the 858D, what is the best temperature to set, and which nozzle to use?Is higher better as its faster?

author: valere
author_rank: Contributor
timestamp: February 17, 2017, 10:21:06 pm
content: Quote from: WaveyDipole on February 16, 2017, 11:52:24 amYou are welcome, it took me a while to find too (was a large one for a 3D printer bed initially). A small one helped me a lot with the replacement of a failed dc/dc chip (nasty QFN with power pad) on an AVR Dragon (a lot of stuff around especially yellow tantalum capacitors). Don't even need to stick correctly, basically shielding from hot air and intensive IR thermal ray. I needed it to protect during desoldering and during resoldering with the new part using solder paste.Quote from: WaveyDipole on February 16, 2017, 11:52:24 amTweezers are okay bad or good it's your confort which change, I do have a set of really decent one (not costing too much), but I dream of the incredible ones I tried once (40€ per tweezers huh I didn't have such a good brand) .However, my advice is not to pull away the component you are desoldering, that's why I put more or less the gravity force on it to push in order to get it sliding away, that way, it will move only when it's hot enough and I have no risk of taking away the pcb trace (which is earier because it's hotter). Sometimes you can't do that if there isn't enough room / too much soldering around.Quote from: WaveyDipole on February 16, 2017, 11:52:24 amI will answer with what can be qualified as a "une réponse de Normand" in French : hot enough, but not too much, fast enough but not too fast.Temp / Heat :start not too high (but at least melting point of lead-free solder, somewhere between 220°C and 270°C if my memory is okay)-keep in mind that if you are too shy, you will harm more than protect, because you will heat far longer to get nothing, that's worse than a bit too high the right amount of time-keep in mind that the heating will decrease dramatically with the increase of the distance between your nozzle and your board/part/pins, to really see how much, take an apple (fruit not device) and try to "burn/cook" the outside, you will see how close and how high temp you need to be. Hot air more or less heat surface not deep. I first did that for fun but it helped me a lot to understand the heating process and find suitable settings for hot air SMD rework- You can take an eye on some datasheet especially from the parts you desolder / solder, you will find the various reflow temperature and limits, generally there is a really huge margin (when it's written, you may find that in separate docs). For example, I suggest you look a bit inside the TI dochttp://www.ti.com/lit/an/spraby1/spraby1.pdf, it will help you to understand how much and for how long a device can handle soldering temp (pre-great then 260°C reflow for 30s for some parts, that's a lot, previously I was afraid to get that high that long, but well that's what the components are designed to handle in the oven.That's what I've mostly done, soldering a really thin package with under power pad or removing IC and replacing it (harder because you really need to not fry the new part, in your case you can cook the older transistor no problem).In oven reflow soldering you choose the reflow profile, depending on the most sensitive part and your soldering paste (which may be changed if the most sensitive part need a lower reflow temp. That's a big science, that I barely know.Airflow :-I learned by trying and feeling how it's going, the idea is you need the biggest possible airflow to heat faster and wider, but... you want your airflow to be low enough to prevent your resistor, capacitor and parts around to fly away (really it's what's happening) if you heat a bit around by accident (especially true when you solder the replacement IC in case it's a nasty QFN or SSOP with a power pad).- If it's not melting, and the temperature is appropriate (more or less), it's often because the airflow it a bit too low (I'm generally not using really high flow).I would choose a Nozzle almost big enough to cover your transistor but not much bigger to prevent from heating too much around (but you can "preheat" around a bit by blowing hot air from a bigger distance hanging around, it can lower the thermal constraints). However in your case it's really not an issue, on another thread we end up saying that at the end of the day except for BGA rework it's more or less useless to have an under quartz heater or to preheat the board.I hope my feedback can help you, but it seems that I do more by instinct and observation on this one, this is knowledge I've yet to consolidate and improve to be able to transmit properly.

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: February 19, 2017, 03:23:30 pm
content: Thanks for your detailed reply. I will let you know how I get on once I have the Kapton tape and replacement parts.Regarding the type of part, I note that on both of the circuit diagrams of the UCH board that I have to hand, that the device used is a BJT transistor rather than a FET so it looks like it will be an RN1106F which also have a couple of built-in biasing resistors. I can't find this package available anywhere at the moment. I have left an enquiry with Littlediode for now so we will see what happens.

author: Monkeh
author_rank: Super Contributor
timestamp: February 19, 2017, 03:37:30 pm
content: Quote from: WaveyDipole on February 19, 2017, 03:23:30 pmYou needn't get the exact part. It's just a prebiased NPN - you can get equivalents easily.This looks to be a drop-in:http://uk.farnell.com/on-semiconductor/dtc143zet1g/brt-transistor-50v-4-7k-47k/dp/2533290

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: February 20, 2017, 08:15:35 am
content: Yes, that looks to have the same . Forgive my ignorance - I am still quite new to SMD components. I noticed on the diagram that some of the relay drivers are NPN and others are PNP. I have ordered both. Thanks.

author: Mashpriborintorg
author_rank: Regular Contributor
timestamp: February 20, 2017, 11:37:22 am
content: I had a similar problem, on a Renault Modus. But in my case the relay and its socket contacts were melted, they were even sordered together my the melting of the plastic. Contacts Inside the relay got disturbed and were permanently stuck. I made a video with an autopsy of the relay box:

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: March 04, 2017, 08:25:16 pm
content: Well this has gone from bad to worse. It seems that the original transistor was low resistance C to B. Once the Capton arrived and the 3 replacement transistors I got to work. Firstly, the transistors that arrived were much smaller - I ordered from memory and although I chose the correct rating I must have picked the wrong item. The pads just reached, but transistors broke easily when heat was applied and I managed to break two in the tweezers and loose the third.In the end I removed the transistor from the foglight on the other side of the board - which I had no problem with - and soldered it into the position of the headlight transistor. Unfortunately this did not fix the problem. Restoring the transistor back to the foglight position did at least restore operation of the fog lights.Since the original transistor was leaky C to B, might this have damaged the output line on the processor?I have also tried a replacement fuseboard which was described as plug-and-play by the eBay seller, but this did not work either. I am now out of options and it looks like I will have to bite the bullet on the cost of a brand new replacement fuse board.

author: valere
author_rank: Contributor
timestamp: March 05, 2017, 11:38:51 pm
content: Quote from: WaveyDipole on March 04, 2017, 08:25:16 pmJust a quick idea. Could you manage to probe (multimeter not scope) the uC output turning on then off for the blown transistor and for the fog light for example, it may allow you to easily know if the uC Output is out of service ?Quote from: WaveyDipole on March 04, 2017, 08:25:16 pmI'm quite surprised about breaking transistors with heat, well maybe those are extremely fragile, because I tried but almost never broke parts by soldering. Well, some components are real nasty bugs to solder, "bloody Murphy" please get out of this board please to the Car functions goes back to normal. On the other end, sometimes I lose small resistors, LEDs, caps, which just fly away from my tweezers (too flat tips in fact).Quote from: WaveyDipole on March 04, 2017, 08:25:16 pmGood job ! and good idea ! Clearly the too small ones must have been really weak.Quote from: WaveyDipole on March 04, 2017, 08:25:16 pmHum, either the Ebay seller wasn't telling the truth, either there is a subtile version difference : indeed, once my car (a clio), was a bit late to be ready for maintenance because one filter (gasoil, replacement is periodical) wasn't available because some have a water sensor and the other no (despite all of them having the same shape, etc.), theatrically, the logic suggests it would be the same for each model (same engine), but in real life there is an astounding amount of variation....

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: March 06, 2017, 10:06:01 am
content: Yes that is what happened to me too. The originals are about 4mm in length. These replacements were only about 2mm. The overlap on the pads was minimal so they had to be positioned just right. Two of them flew off from my tweezers as I was positioning them. I found them on the table and both had the same corner and one leg broken off. The remaining one flew off as well, but before I managed to get it to the circuit board. I have so far not found that one!The problem with probing, although it sounds like a good idea, is that it would have to be done while the unit was connected to the car, but the fuseboard unit has to be disassembled to get access to the board. I had thought about disconnecting the links between the two PCBs from the foglight and dipped beam relays and connecting the foglight control output to the dipped beam relay. That way the dipped beam could be operated via the foglight switch but it would mean sacrificing the auto feature and the foglight.I have just been put in touch with another garage that services Renault cars and I am awaiting a quote for a replacement new versus a used fuseboard and programming. Perhaps this will be a bit cheaper than the main dealer....

author: valere
author_rank: Contributor
timestamp: March 07, 2017, 02:45:16 am
content: Quote from: WaveyDipole on March 06, 2017, 10:06:01 amYou probably already know, but in case not : put some solder on one pad before, then melt and maintain melted solder, put the part, then let cool down, then you can solder 2 other pads (even if there are small gaps, often doable), then re-solder first one. Sometimes I use one of my electronic clamps which has a relatively narrow tip and a lot of grip (parts are not flying away), but not as easy as good tweezers in a densely populated boardHum, I know I'm a bit crazy regarding the patching ability on board level, I like it to be rock solid and almost invisible. Like use a bit of wrapping wire under a SSOP FT232 to rebuild the track damaged due to bad quality pre-sensibilized PCB... don't tell anyone.Quote from: WaveyDipole on March 06, 2017, 10:06:01 amWell, that's the time when you hesitate to put long wires on those two signals (2 uC outputs + GND) to be able to probe it on the live system... I can perfectly understand that you are not motivated to do that (especially since you probably need wrapping wire size wire, with a good insulator/not melting when soldering, and hot glue to prevent accidentally destroying the PCB track with the long wire) that's guessing you can "easily" output the wire out of the reassembled thing...As far as I'm concerned, I would really not go for a full time function exchange between foglight and dipped beam, but it's personal.I do tend to get lazy on this sometimes, soldering probe wire on a live system, not so easy to access, is well... really annoying if it's not absolutely needed. I do have a proper IC current amplifier to measure current on the custom battery management board of our autonomous robot, I've never had enough additional time to investigate again why we couldn't read two analog channels (the other is for battery voltage - and it's way more important), maybe a silicon bug (uC is a nasty low cost one), maybe a "between chair and keyboard" bug, once we needed to measure current consumption during move (engine consumption), and I never took the time to solder two long wires directly on the board to get the current consumption waveform with a scope, a scope current clamp probe would, however, be a nice way, but I do not have one yet.Quote from: WaveyDipole on March 06, 2017, 10:06:01 amIf you can get a "used" one from a similar car which had an accident (no idea of the English word for the place where crash cars are stored and parts retrieved), it would be a good way to pay it less maybe.Anyway I wish you good luck and hopes that you will manage to get a proper and affordable fix !!

author: Messtechniker
author_rank: Frequent Contributor
timestamp: March 07, 2017, 04:20:43 pm
content: Quote from: valere on March 07, 2017, 02:45:16 amCar bone yard

author: valere
author_rank: Contributor
timestamp: March 07, 2017, 10:17:01 pm
content: Quote from: Messtechniker on March 07, 2017, 04:20:43 pmThanks, I'll try to remember this new word.

author: WaveyDipole
author_rank: Frequent Contributor
timestamp: March 21, 2017, 05:20:45 pm
content: The bottom line on this was that the main fuseboard had to be replaced an coded at considerable cost. There was no other way around it. After doing everything I could myself, I eventually took the car to an independent Renault specialist garage. They investigated and found that it is not possible to fit a used fuseboard and re-program it so a new one had to be ordered. I had suspected this might be the case as I had found information on the internet to that effect as well. They also acknowledged that the relay sold to me by the Renault main dealer was incorrect for this model and I should never have been asked to modify it. This part should never had been fitted. The also said something about a 'blown feed to the BSi'. Anyone know what one of those is?In any case, the job is now done with 12 month repair warranty.

author: valere
author_rank: Contributor
timestamp: March 22, 2017, 12:21:13 am
content: I'm glad to know that your car is fixed(even if the cost is well not a happy ending).On another level, I feel quite unhappy that such exchange can't be done because of close coding and so on (maybe there is a good reason maybe it's more about business... knowing that it's most likely that the car equipment manufacturer really get their money from replacement parts not from first installed ones).