|
I would start by replacing the pollen/cabin filter.If i recall,if this becomes blocked it affects the air temp sensor operation.Worth a try.hth
|
|
Sorry, I should have said - the car had a full service yesterday including the pollen filter - no change with the heater :-(
|
|
The system is working normally, climate control maintains a constant temperature in the car (or try's to) when the interior temp exceeds the heat level you have selected it will try to lower the temperature by blowing out cold air. Logical.
|
|
Seems like one of the 4 sensors that informs the automatic climate control "computer" is faulty. This hopefully could have been more precisely detected if a request had been made for that particular computer to have been interrogated when the vehicle was serviced! The 4 sensors are:- 1 the evaporator sensor located in the "heating system" and fairly easily accessible from inside the passenger side, which could well be the problem one; 2 the interior temperature/humidity sensor located in front of the interior mirror; 3 the interior sun sensor on the top of the facia panel (round press in type sensor) & 4 the exterior temperature sensor - the dome that is below the LHS wing mirror. Ideally the heating system computer should be read to check out the sensors. But I reckon that the evaporator sensor is the one to look at first -- and is what I would do. It is Renault part 7701048762 if you want to take a £12-13 chance! It can be changed by a reasonably competent DIY person (tricky to push in and turn etc) but if that is not for you, then skilled assistance is required.
|
|
Thank you, Fernando - that's very helpful. But what about the fact that the heater still blows cold when the aircon and auto buttons are both off? Does the heater system still use those same sensors even when it is acting as a standard heater?
|
|
The sensors inform the computer that controls the (auto) climate control system when heat/cooling is needed. The "where" is determined by the manual selection of the temperature for each side as per the screen. If the aircon button is on you simply get aircon cooled air coming in. The heater needs to be told to operate (by the computer informed by the sensors) if hotter air is required to be mixed in, which is where the evaporator sensor comes in. There is also a "mixer" motor that blows the required hot/cool air to each side, which can be tested when the computer is interrogated. And sun heating up the fascia sensor turns down the heat/ gives colder aircon as required. But my money is on the evaporator sensor as I had the same problem and replacing this sensor cured it!
|
|
It all sounds very complicated to a mere female lol, but I will be down to Renault first thing Monday morning for an evaporator sensor :-) Will let you know. Thanks again.
|
|
I just wondered - I've noticed a buzz from the box by the rear view mirror - do you think that might be significant? I'm wondering if I should get that sensor changed first rather than the other one?
|
|
Hmmm - it could well be and I think you should check this out first. Here goes :- in the box referred to, is an electric motor unit that drives a small fan that sucks an interior air sample past a sensor! The fan can easily become blocked/obstructed by fluff etc over time, which could cause a problem and maybe why a buzz can be heard from the box. If the front cover is pushed carefully forward to unhook it, the motor unit can be inspected & removed with a bit of care and the fan cleaned by a suitably skilled DIY mechanic. You can even wire it up again and see if the fan works. The motor unit (inc the sensor) costs some £52 so you need to check if it is working before you consider spending. But if you find that the fan was not operating and it works again after cleaning etc, you then need to check if the heating is working as it should because the sensor(s) may not be faulty. If you find after sorting the fan, that the heating is not working, I still reckon that step 1 is to replace the evaporator sensor. It seems a complicated system but as you wrote earlier it works well when it is all in order. And you need to get it sorted to get heating/cooling in future. The alternative is a Renault dealer computer diagnosis (of the above) and fix....!
|
|
Thank you so much for such a detailed reply. I've had a look at the unit and tried to get into it, but I couldn't work out how to do it. Do I have to take the rear view mirror off first, as it seems to be in the way.
|
|
Very interesting, with extremely detailed information, however, I still think it is normal behaviour for a climate control system, if mine starts blowing cold I just adjust the temp setting up by a single notch, it then blows hot again, until it reaches or tries to exceed that setting, whereupon it cools the cabin down again with cold air. I am sure your Renault dealer will happily sort things out for you.....
|
|
It definitely isn't normal - it blows cold always unless it's on 26. I either have to have very cold air blowing or very hot air blowing. Anything up to and including 25 is cold - 26 is hot - no matter what the temperature of the car is.
I'm sure my Renault dealer would be very happy to sort it out, but at £100 an hour I just can't afford it.
|
|
I have had exactly the same problem as yours and fixed it myself as set out above. The way to access the motor at the rear of the mirror is to carefully (but positively) prise the front plastic forward at the top RHS and LHS of the unit where the front cover joins. You will need to insert a smallish screwdriver and turn the blade as a lever to release the cover from the clips to start it moving. It will gradually give way and and all will then be revealed. The harder bit for you will be if you have to replace the evaporator sensor, which is tricky to push and turn etc - but can be done with patience and determination.
|
Right. So today I got the cover off by the rear view mirror. The fan inside was working but it was very dusty and dirty. I cleaned it with cotton buds, but unfortunately this made no difference to my problem. I couldn't see where the sensor was in there, but I'm going to go to Renault tomorrow for an evaporator sensor, as I guess that's the next step? I might get a Haynes manual too and try to do it myself - do you think I'll be able to? Could you please tell me exactly where the evaporator sensor is, and also where the one in the rear view mirror thing is? Maybe I should change them both?
Someone I was talking to today said that it could be the actual heater unit itself or the heater matrix - both lots of money apparantly :-( I also asked my mechanic if he could do the computer thing but he doesn't have the right equipment, so if I go down that route I'd have to take it into Renault I think :-/
|
|
I,m not convinced an evap sensor will fix this.This sensor is only active when the a/c system is switched on.It could possibly be a fault with the heater matrix .A partial blockage can reduce the flow of hot engine coolant through the heating system thus reducing heat efficiency.Even a faulty engine water pump can have the same affect.(seen this many times on VW models)hth
|
|
If you read my post of Sun 13 Mar 2011 21:27 carefully, it sets out what you should do if the fan is working but there is no change to the heating problem - you should replace the evaporator sensor (ES) first of all, then test out the heating again. It is highly unlikely that there is a problem with the heater matrix unless the coolant has not been changed for years and the water channels are blocked etc, which cannot be the case if you recently had heat and still get heat in the "26" setting! The good news is that if you have managed to get the cover off the motor/sensor unit by the rear mirror etc, you should be able to change the ES! It is located below the water pipes to the heater on the LSH of the air supply unit housing behind the fascia panel. On the passenger side, you unclip the plastic trim piece from the passenger footwell at the side of the centre console. The ES is about the size of a thin pencil with a flattish top, with a wiring connector that is removable, goes down a tube and is fixed by a 90' push and turn and reverse for removal. When you look at the replacement ES you will get a better understanding of what you have to do. Again, you need patience and determination to accomplish this! I think you will find that this will get your heat coming again as you need it. I would not do any more at this stage. I recommend that you get the manual referred to above especially if you are keeping the vehicle and intend to do some of your own car fixing. Finally as you have discovered, you need to have the computer interrogated by a garage that has the right "equipment" and that is the Renault dealer, although I believe some independents can obtain the software package required.
|
|
Thank you, Fernando. Having read the instructions you've given on how to change the ES, I've decided to phone Renault tomorrow and get it booked in for diagnosis. I don't feel capable of doing what you describe, bearing in mind I have no mechanical knowledge whatsoever! Once I get the diagnosis and actually KNOW what the problem is I can get my local mechanic to fix it on a nicer hourly rate than Renault! Thanks so much - I will let you know the outcome.
|
|
Sorry, just to add - will the fault diagnosis pinpoit the heater matrix if it's that at fault? I'm worried about spending the money on the diagnosis if it isn't going to tell me exactly what the problem is.
|
|
I'm in the centre console bit where the pipes are but can't find the sensor anywhere. If anyone happens to be online now who knows plz could they help me :-)
|
|
OMG FERNANDO I COULD KISS YOU!!!! I changed the evaporator sensor and it's fixed!!!!!!!!!! I can't believe it - thank you thank you thank you x
|
|
Is your Head Gasket Leaking? Is your coolant expansion tank covered in dry coolant? Does it whoosh (depressurise) significantly when you open it and then the coolant level recede?
|
|
Fernando - thanks thanks thanks!
I had the same symptoms , heating on 26 deg , all other temperatures cold air.
Did change the filter , ( dirty ) but this did not help. Got the evaporator sensor- approx £12 from Renault - changed - ( took me a while to locate it) and works as a charm.
Sensor came with soft washer which made fitting close to impossible but my previous one did not have one, so removed the washer from the new one and job done)
Thanks again for great advice.
|
|
Hi all, I have exactly the opposite situation, cold air on 16, hot on all other. I believe that is also connected with the problem with external temperature sensor. Outer temperature is higher for a 7 deg, Celsius than it shows.
Another problem with climate control is that when engine goes over 2200-2300 RPM, cooling turns off. I can live with that driving in the city, but when I go on a highway in a summer it becomes unberable.
If anyone have some idea, please...
|
|
If it is hot in the car ie above actual 16 deg C, the air conditioning system, when set to a 16 deg C inside temperature requirement, should produce cold air to cool the inside down to16C. Could be that the outside temp sensor is faulty/has a bad connection, given the disparity of readings you have described. You either pay up and have the air conditioning system computer read for any faults by a Renault dealer (and have them fixed?) or if you are a competent DIY mechanic and think that removing the NS mirror glass would not be a problem for you, take a chance and replace the sensor, part No 7700773858, at a cost of ~£25 - according to the link above.
|
|
Hi dre_magnus Reading through these posts I found yours with the same problem I have on my Laguna 2005 air con which switchs off the cold air over about 2200-2300 revs, only ambient then flows, and comes back when I slow down .Did you ever solve this , I have just had a new pressure switch fitted but no difference, the system is charged,etc. Hope you are still out there or anyone else that can help.
|
Fernando
I have the same problem can you tell me where the polen filter is and where the sensor is, is it in the mirror or in the sun roof control box.
Thanks
MartMan
|
|
Which problem are you referring to? Why do you think that the pollen filter, located in a plastic housing behind the glove compartment, is causing a problem? As an aside, it should be renewed at 18K miles or more frequently anyway. I have explained in an earlier post (March 2011) where the sensors are located but need to be clear about the problem before I consider which sensor(s) might be involved.
|
Fernando
Thanks for getting back
The problem is that both the air con and heating only work at 26 degrees it was fine two weeks ago during a long trip.
I have no recollection of the polen filter ever being changed.
I've read that the sensor somewhere near the rear view mirror can get blocked or just fail but I am unsure as to it's location.
MartMan
|
|
My post of Sat 12 Mar 2011 11:11 above covers the evaporator sensor, which is what I reckon you need to change given the information you have just provided. If you read on a bit more, you will find out about the interior temperature sensor that you refer to, which is located behind the rear mirror!
|
Thanks
Will let you know the outcome.
Do you know any thing about parking sensors, mine stopped working about a year ago, for a while I would get the occasional squeak but I don't even get that now.
MartMan
|
|
Hi Fernando,
My parents Laguna heater acting up although not quite the same symptoms as above.
In their case, the fan motor only come on after a delay. Could be 5 seconds or could be just after you reverse out of the drive, or it might not come on at all that day! Also, when it does come on, it will blow warm air on passenger side to feet, face or screen as required but only cold air to all three levels on drivers side.
I think the heater motor resister may be failing and 1 or more blend door or mixer actuators has failed. What do you think? I've heard they are nigh on impossible to get at in Laguna without removing the dash... any idea?
Ta
|
|
It is normal for a delay when the climate control system is switched on because the computer needs to evaluate the information from the sensors before the system can operate as required. Given the symptoms you describe, I believe your diagnosis that the mixing flap motors are not working as they should, is correct. I think you will have to face up to a Renault Service Centre (RSC) CLIP computer test to hopefully determine exactly what the problem before you try to fix it. BTW some RSCs make a reduced labour charge if the vehicle is over a certain age. The way to access the "heater" is to remove the card reader from the fascia, the heating control panel and then the trim panels from the footwell. But this is a task for an experienced DIY mechanic.
|
Fernando
Thanks
The heating is now working, I was able to remove the cover complete with sensor and fan without any tools. I was unable to remove the plug must be a security tab somewhere but due to its location I was unable to see. I removed the sensor assembly from the hosing and with a small art brush removed the dust and fluf from the sensor and the fan. The fan is not as noisey now and the heating is working.
Do you know any thing about parking sensors?
MartMan
|
|
Good - another satisfied reader of "Technical Matters"! You must have strong hands btw. The plug can be removed by releasing the catch that keeps it in but the fan and sensor can be cleaned without being removed. I hope that the heating is working as it should because the symptoms you described pointed to an evaporator sensor failure.
Regarding the parking sensors, I guess that selecting reverse switches on the parking aid system and the first step is to have a look around the gearbox, which you have not given details of, to see if the wiring/connection is ok. Are the reversing light(s) ok? Fuse F4 (20A) is the one for the parking aid + reversing lights etc. There are also the parking aid control unit connections to consider.
|
Fernando
Thanks for getting back
The reversing lights are fine as there were a view squeaks from it before it totally stopped working I'm guessing that it's the control unit. Do you have any idea where they hide these things, it's a factory fit. I have also heard that the wiring on each sensor can come lose/break do you know how to remove the sensors for inspection?
MartMan
|
|
1 In the boot.
2 The wiring to (most of) the sensors can be seen from behind the bumper. You might just be able to remove 2-3 sensors without removing the bumper to gain proper access to them.
|
|
Can anyone advise me please? I've read all the posts I can find and not found a solution to my problem.
The climate fan on my Laguna always runs at max speed when on auto. It starts slow when the car is first started and then builds to max as the engine warms up, and then stays there.
I have cleaned the temperature sensor behind the mirror which was awful and replaced the pollen filter which wasn't too bad.
I've also replaced the climate computer. Not to solve this problem, but because the backlight had failed for the third time, and I couldn't solder it again and because it would suddenly set the temperature to 16 or 24 without being touched and the driver's temperature setting dial wasn't working properly when turned.
Changing the temperature each side and changing which vents are used manually, works fine. I'm satisfied that the mix motors and vent motors are functioning as they should.
However, sometime the air to the drivers footwell feels cooler than the air on the dash vent.
And further advice gratefully received.
Edited by mukiwa on 04/03/2013 at 12:55
|
|
1) What temperature is set for each side? 2) When the fan continues on max, does the interior heating match the temperature that is set ? 3) Does the temperature need to be set to the max < 26c to get heat coming? 4) When the drivers footwell feels cooler, is it sunny at the time? 5) Do you know if the motor (fan) is operating for the int temperature sensor behind the mirror? 6) Did the fan slow down, say to setting 3, in the past? 7) When the heating is run on manual, do you get the right amount of heat coming out? PS Not sure why you started a new thread of correspondence in the middle of it all!
|
|
Hi Fernando or anyone else that can help!
I've been reading your really helpful advice, and wondered if you would be able to help us please. A week ago we bought a 2007 Renault Laguna 2.0 DCI, with only 49k on the clock. It started fine this morning, but when I tried to start the car at lunchtime it just clicked and wondered turn over. It had a new battery put on it 6 months ago, so I looked to see what else was wrong and I found that the 100amp starter motor fuse had gone. I had noticed a couple of other issues, for example when I put the wipers on the first setting it did one slow wipe and then went on full speed, also the heater blower stopped working when the big fuse went. Do you think this could be connected? I've done some online research, and I'm not sure if the 100amp fuse was big enough. Do you know what size it should be? I've replaced the fuse to get it started, but as the heater blower has stopped working I'm not sure what to do next. I would really appreciate your advice. Thank you,
|
|
You need to check the appropriate handbook for the fuse sizes including the fuse for the heater blower. Also check that charging is correct. You should get ~ 14.4 volts across the battery terminals when charging is taking place. Is the starter motor faulty in some way? .
|
|
Hello all I same problem with my heater it was working fine now it blowing a small amount of air though but no power.
I have changed the cabin filter with no change to the heater.
Can somebody offer me some advice please ?
|
|
|
|
|
|
Hi Fernando P,
Not sure if you still use this site still as thsi post was some years agao now, but having read your posts on here regarding the heater control (or lack of) I bought and fitted a new Evap sensor as I had the same issue of all heat on or all cold on no in betweens. It has sorted it right out.
The fitting was not so straight forward as I have shovels for hands, but managed it eventually. It took me about 20 minutes as struggled to get the old one out.
I just thought I would send you a message and thank you for your advice, as I spoke with Renault and they quoted about £345 plus VAT to check and sort out teh problem as it could be a number of things.
Again thank you and all the others here for asking the questions etc which promted your responses and I hope you all had a gr8 Xmas and New Year.
Thanks again,
Dave.
|
|
|
|
|
