Air Con Failed x7 - just when I needed it

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

User avatar
petef
Posts: 190
Joined: 23 Jul 2006, 20:46
x 10

Air Con Failed x7 - just when I needed it

Post by petef »

The Air Con failed on my 2009 C5 x7 2.0l Hdi Tourer just when I most needed it - en route in France in temperatures of 36 degrees plus. I realise that there is at least one parallel thread running on a similar subject but I think this is a different issue.
On the road the fan stopped blowing cold air. When restarting the next day and pressing the air con switch an audible click is heard, cold air is produced for maybe 5 seconds and then there is another click and refrigeration stops.
Having arrived at our house in the Dordogne and plugged into the Lexia, it shows a fault in the Injection Section - 'Permanent Fault - Cooling function integrated into the ECU. Coherence between fan speed and setting.' The fault code is P0495.
The engine fan, whilst free to rotate, does not kick in when the air con switch is pressed. Maybe there is a sensor or some other controller which is failing to turn the engine fan on, so that the air con shuts down? - the supply voltage of 4.99v shown in the one screenshot seems low? And where is this sensor? Or maybe the fan itself has failed, or a fuse, or what? Aaaaaargh! - in this heat the car is unusable.
I cannot see where the wiring and connectors are for the fan to check them. The air con was working fine previously, the condenser was replaced and system recharged about two years ago.
Help please
Attachments
air con 2.jpg
air con 1.jpg
User avatar
xantia_v6
Forum Admin Team
Posts: 8145
Joined: 09 Nov 2005, 23:03
x 553

Re: Air Con Failed x7 - just when I needed it

Post by xantia_v6 »

Check carefully all the fuses that could be associated with the cooling fans, check that they are not blown and that the contacts are clean.
User avatar
GiveMeABreak
Forum Admin Team
Posts: 29046
Joined: 15 Sep 2015, 19:38
x 3614

Re: Air Con Failed x7 - just when I needed it

Post by GiveMeABreak »

And correct that if the cooling fans will not operate, then the A/C will be shut down to prevent overheating as a protection measure.

If you want the diagram I'll need the VIN Pete - I don't recall having this one only for the C4.
User avatar
petef
Posts: 190
Joined: 23 Jul 2006, 20:46
x 10

Re: Air Con Failed x7 - just when I needed it

Post by petef »

Thanks for replies. Will check fan fuses when I can track them down.
Vin number is VF7**************[VIN obfuscated, can be read by forum staff].
Whilst a wiring diagram is always useful it's the location of the sensors, wires and connectors that would be useful.
Not that I'm going to check anything outside at the moment - it's still in the high 30's
User avatar
GiveMeABreak
Forum Admin Team
Posts: 29046
Joined: 15 Sep 2015, 19:38
x 3614

Re: Air Con Failed x7 - just when I needed it

Post by GiveMeABreak »

Some points of note Pete on the A.C system in the X7 (DW10BTED4 specifically)- specifically conditions that will shut off the compressor below, but looking at the P0495 fault - I think this is the cause of your problem and the descriptor of the fault is:
Engine ECU DELPHI DCM3.4
Fault codeP0495
After sales description of the fault codeCooling Function Incorporated in the ECU ( electric cooling fan unit) : Coherence between cooling fan fast speed and the reference
Description of the diagnosticsThe fan unit is controlled at low speed and the actual speed is not low speed or if the fan unit is not controlled but even so is engaged
Conditions of activation of the diagnosticsConsult the associated contexts for the Pcode forwarding conditions
Conditions of disappearance of the faultDriving for 5 minutes
Down-grade modes if fault presentAir conditioning cut-off
Reduction in the activation thresholds for the coolant temperature alert
Switching on of the warning lamp and/or warning message-
Main customer complaints likely-
Suspect areaselectric cooling fan unit
The other info below is just for information and provides other reasons for shut off.

I will get a wiring diagram up of the fans - as at least you can check the circuit. It's not likely not be anything else with the fault code clearly giving the reason for shutting off.

Air conditioning fluid pressure safety
The air conditioning high and low pressure safety management status is transmitted by the BSI via a linear pressure sensor.
The linear pressure sensor measures the pressure of the air conditioning fluid.
The reception of pressure information is carried out by the engine ECU through a wire link.

When the pressure of the air conditioning fluid is below 2,5 bar, the air conditioning compressor is cut off.
The air conditioning compressor is triggered again when the air conditioning fluid pressure increases to above 3 bar.
When the pressure of the air conditioning fluid is greater than 26,8 bars, the air conditioning compressor is cut off.
The air conditioning compressor is reactivated when the refrigerant pressure falls below 20 bars.
[color=#800080Note that the pressure values indicated are the values returned by the diagnostic equipment and do not correspond exactly to a pressure value measured by a special tool.[/color]

Safety as a function of exterior temperature
When the exterior temperature is below 3°C, the air conditioning compressor is cut off.
The air conditioning compressor can be reactivated (according to the temperature requirement or the user request) when the exterior temperature rises above 4,5°C.
When the exterior temperature is below 5°C, the function linked with the air quality sensor is deactivated.
The function linked with the air quality sensor is reactivated when the exterior temperature is higher than 5°C.

Safety in relation to the engine coolant temperature
When the engine coolant temperature is higher than 80°C, the passenger compartment air heating resistors are switched off.
The passenger compartment air heating resistors can be reactivated when the engine coolant temperature is below 80°C.

Safety as a function of the electrical diagnosis
The air conditioning compressor is cut in the following conditions:
  • Air conditioning compressor clutch fault
  • Air conditioning compressor electrovalve fault
  • Air conditioning fluid pressure sensor fault
  • Air blower fault (delay of 30 seconds)
  • Fault in communication between the engine ECU and the built-in systems interface
  • Fault in communication between the engine fuse box and the built-in systems interface (BSI1)
In relation to the exterior temperature: A fault on the evaporator sensor does not result in cutting off of the air conditioning compressor but a fixed value of the air conditioning compressor electrovalve control (See the table below).
Exterior temperature (°C)-40351025354580
Air conditioning compressor electrovalve (%)0303030456570100
Sensor fault: Coolant pressure
When a fault is detected on the refrigerant pressure sensor:
  • The air-conditioning control panel takes as default value 10 bars
  • The activation of the air-conditioning compressor is prohibited
Engine coolant temperature sensor fault
When a fault is detected on the engine coolant temperature sensor, the air-conditioning control panel takes as default value 85°C, (for any type of engine).

Outside temperature sensor fault
When a fault is detected on the exterior temperature sensor, the air-conditioning control panel takes as default value 18°C.

Sensor fault: Evaporator temperature
When a fault is detected on the evaporator temperature sensor, the air-conditioning control panel takes, by default, one of the following values:
  • 5°C when the air-conditioning compressor is controlled
  • The value of the exterior temperature when the air-conditioning compressor is not controlled
User avatar
GiveMeABreak
Forum Admin Team
Posts: 29046
Joined: 15 Sep 2015, 19:38
x 3614

Re: Air Con Failed x7 - just when I needed it

Post by GiveMeABreak »

Ok, so here is the wiring diagram of the Cooling Fan Electronic Mixer. It is item 1513 on the Diagram. Here is the location on the vehicle of the unit, plus the fuses controlling the circuit - so you should have everything you need to check the circuit.
1513 Cooling Mixer.PNG
1513 Cooling Mixer.PNG (16.31 KiB) Viewed 1576 times
Wiring Diagram
Wiring for 1513:
2 Pin Black Connector
M1513 : EARTH M1513
B151C: Fan assembly high speed control (controlled by Maxi Fuse MF1 in the Engine Compartment Fuse Box)

3 Pin Grey Connector:
1589: Fan unit module power supply (Controlled by Fuse 21 in the Engine Compartment Fuse Box)
1599C: Fan unit diagnostic info
1540C: Fan control 1 (-)

1320 is the Engine ECU
1220: is the Engine coolant temperature sensor


Image
User avatar
petef
Posts: 190
Joined: 23 Jul 2006, 20:46
x 10

Re: Air Con Failed x7 - just when I needed it

Post by petef »

Thanks for all the detail Marc. I have now had a quick look - car is now in a relatively cool barn and I am relying on the Activa for current transport - until the next LHM leak that is . I checked fuse 21 in the BSM,; as it is only 5amp I thought that it might have gone. No chance - why is it never the fuse that ever fail??? Incidentally the Citroen Handbook is absolutely useless - gives a picture of the fuses in the BSM under bonnet fusebox but fails to number them in the pic so the accompanying legend is of no use whatsoever. I can't get to the maxi fuses without taking the BSM out which I am not prepared to do at the moment. As a further aside the maxi fuses don't even get a mention in the handbook. With no Haynes manual I am having to rely on my French Revue Technique manual which is actually quite good.
So now I will have to investigate the fan and it's wiring . My main query now is relating the wiring diagram to situational reality. It would appear from my Citroen Service 'Removing Refitting Fan' that the ' Cooling Fan Electronic Mixer' you refer to may actually be integrated into the cooling fan itself - item 1513 in the wiring diagram clearly shows a fan within the same boxed perimeter. or have I got that completely wrong? The situation is further clouded by the parts section of Citroen Service indicating a relay in the line - part 6545XF although that doen't show at all in the wiring diagram.
Any way I will have a go in the next day or so at taking off the under bumper and checking out the fan as far as I can. If the fan and it's associated electronics does seem to be the culprit would I be right in thinking that the replacement part number is 1253L6 (my RPO is 11493)
Happy days - only 33 degrees today - who needs air con?
User avatar
petef
Posts: 190
Joined: 23 Jul 2006, 20:46
x 10

Re: Air Con Failed x7 - just when I needed it

Post by petef »

So I have had to take a few days off from trying to sort out this problem. Won't go into details but it involves a totally blocked outlet on the septic tank, so you probably don't want to know any more any way.
All I have managed to do so far is tonight, to perform an actuator test on the cooling fan with the Lexia. This came up as 'Impossible' on the lower speed and the higher speed would not kick in either. So It seems highly likely that the fan itself is defective or it's associated electronics. When I briefly tried the air con about 3 days ago the fan did start up and ran for about 1 minute. However it then stopped and the air con, which had started to cool everything down, shut off. Fault still shows as P0495.
I come back to my previous question - is there a relay in the line? - seems like there may be on in the wiring in the fan shroud. See pic. And is it part number 6545 XF? If it isn't that then it must be the fan itself which will be a lot more expensive.
Attachments
C5 x7 fan.PNG
User avatar
GiveMeABreak
Forum Admin Team
Posts: 29046
Joined: 15 Sep 2015, 19:38
x 3614

Re: Air Con Failed x7 - just when I needed it

Post by GiveMeABreak »

Yes that is the relay, 50 Amp Pete, Number 3.
04253F3F-5B65-4847-9AEE-49A325A5DD56.jpeg
User avatar
petef
Posts: 190
Joined: 23 Jul 2006, 20:46
x 10

Re: Air Con Failed x7 - just when I needed it

Post by petef »

Thanks Marc. I have now removed the relay and it seems ok. So next out was the fan which would appear to be the culprit. Could you please confirm the part number for me. Mine is different to the photo I posted - the relay and associated socket wiring etc are in a vertical box with cover alongside the fan. Looking at the new prices for a fan I may have to get a second hand one if I can track one down here in France.
What a joy....
User avatar
Paul-R
(Donor 2020)
Posts: 5821
Joined: 07 May 2009, 16:24
x 942

Re: Air Con Failed x7 - just when I needed it

Post by Paul-R »

The quite often problem with the fans is that they don't get activated at all over the winter and seize up. It happened to both my Mk1 C5 and the Xsara. Both blew the maxi-fuse and one of them burned out the relay. I also separately discovered that on one of them the speed dropping resistor had burned out.

Can you rotate the blade by hand easily?
User avatar
petef
Posts: 190
Joined: 23 Jul 2006, 20:46
x 10

Re: Air Con Failed x7 - just when I needed it

Post by petef »

Fan had been working fine over 4 days driving through the French heatwave. It still rotates freely, just not under power.
User avatar
GiveMeABreak
Forum Admin Team
Posts: 29046
Joined: 15 Sep 2015, 19:38
x 3614

Re: Air Con Failed x7 - just when I needed it

Post by GiveMeABreak »

petef wrote:
09 Jul 2019, 14:15
Thanks Marc. I have now removed the relay and it seems ok. So next out was the fan which would appear to be the culprit. Could you please confirm the part number for me. Mine is different to the photo I posted - the relay and associated socket wiring etc are in a vertical box with cover alongside the fan. Looking at the new prices for a fan I may have to get a second hand one if I can track one down here in France.
What a joy....
Hi Pete, the part you want for the fan assembly is: 1253T3, (160W DIAM MAX 415). These are £486.77 inc. VAT from Citroen, but a selection on the bay:

https://www.ebay.co.uk/sch/i.html?_from ... 3&_sacat=0

Wach out for some 'unknown' brands - there are genuine ones that range significantly in price though.

There is a genuine Citroen one there for £229 + £12 postage from Poland.....
https://www.ebay.co.uk/itm/Original-Coo ... Sw8DJZ~G1x
User avatar
KennyW
Donor 2022
Posts: 2281
Joined: 17 Jan 2006, 22:22
x 85

Re: Air Con Failed x7 - just when I needed it

Post by KennyW »

Pete,

Can it be a broken wire feed to the fan ? Common problem on Xantia's air con resulting in melt down at the relays.bypass live feed to fan to confirm fan working then it is a case of methodically working through the wiring to fan / relay to find break.

Kenny
User avatar
petef
Posts: 190
Joined: 23 Jul 2006, 20:46
x 10

Re: Air Con Failed x7 - just when I needed it

Post by petef »

So, continuing the saga in more of a blog than forum posting, off we went this morning to local big town Perigueux in what I thought would be a forlorn search around the breakers for a second hand cooling fan. I had low expectations because, whilst there are many x7's in France, they are seen as relatively new and not ready for breaking. The exception, of course, is finding one that has been written off in an accident. First stop was Verdier Casse Auto in Trelissac. Much sucking of teeth when I said Serie 3 Citroen C5. Then the lad driving a fork lift truck pointed over the other side of the yard to the remains of an x7 saloon. I say remains because it looked as if it had rolled over and over several times. - every panel was at least bent and the roof panel was definitely in a coupe position. Most of the front was just plain missing, but at least you could see what was left of the cooling system. Initially I thought the fan was completely broken, but it turned out that it was just the surround that was shot, the fan itself was intact. So a helpful guy rapidly dismantled it and the patron only asked 50 euros with the wiring and relay included, together with a 3 month warranty.......
Hotfooted it home and fitted it this afternoon..... and it works!!
Happy bunny so far. Don't know how long it will last, those revolutions in the accident plus the sudden stop will probably have reduced it's life somewhat; we will see. Compared to a new one from Citroen at £486.77 - thanks Marc - I will take a chance.
Looks like the old one has failed electronically inside the fan housing. I seem to remember when I had to replace the fan on the Activa some years ago for the same reason, you could separate the electronic 'boitier' from the fan and replace that separately. Advice was even available about replacing some of the transistors inside. Perhaps the time is right to explore the innards of the x7 fan to see if they can be repaired. I know now that genuine new ones are available from Poland for £220+, but that is still a heck of a lot of money if a transistor or two for a fiver is all that is really wrong.