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Thanks for the tips.

I measured the pressure sensor plug and it has +5V (usual in sensors), ground and a signal(?) pin.
When i short the 5V to ground the revs change. That happens also when i unplug it while the engine is running so i guess the ECU gets the impression that the compressor is turned on and raises revs. But the compressor clutch never engages.

How can i get to the AC self diagnostic mode? I don't think i need it though, i'm pretty sure the CLIP tells me the right information. I also got a tip to try turning on the AC with defrost on, that way it should bypass the temperature sensor. The AC still won't turn on. There is pressure in the system so it hasn't leaked.

I also found and cleaned the 2 temp sensors' connectors.

I read that in some systems removing the pressure sensor doesn't release the gas. But i suppose in this case it does. Even if i get a working sensor how can i test it without getting the right pressure to it?

My best guess is that the 3-wire sensor measures both low and high pressure by varying the resistance, so i should get something between 0 and 5 volts to the signal pin. 0 is empty and 5 is too high. Somewehere i read that usually 1V=100psi but what might be the correct pressure?

Is there a relay or fuse somewhere for the compressor clutch? I only know of the one fuse in the cabin which also is for rear window heater and such.
Is there a way to force it to engage?

edit:
I found a pdf about Renault AC: http://www.uas-bg.com/meganii/eng/6001A.pdf

There's a chapter on pressure sensors:


When looking at pressure values that 1V = 100psi sounds reasonable. 2 bar low limit should be 0,23V, high limit should be 3,91V. Now if i use a suitable resistor to get the voltage between those values i should get the clutch engaging if the fault is in the pressure sensor.

another edit:
I now have a voltage reduction thingy made out of a 750Ohm resistor and a 1kOhm potentiometer which allows me to change the voltage between 0 and 3,6V.

I didn't know there was one so I cannot help.



CLIP once diagnosed a broken wiring loom on one of our old cars along with a dead TDC sensor. It turned out to be the head gasket at fault.



We've had 3 safranes and none have ever leaked.. except the current one but thats because it suffered a crash with a volvo.



Pressure sensors sense the pressure. As far as I know, there is no way to do that without direct contact with the force that is being meassured. As for how you can test it.. I don't think you can other than using external electronic equipment to get the readings from it - but even then you can't be sure the sensor is working - only that it outputs a reading.



There is a little red wire I mentioned previously - it comes out of the wiring loom and sits on top of the plastic - then runs into the AC pump. If you pull it off the plastic part of the wiring loom you can pull the connector apart. As far as i know, that is the control wire for the clutch but i have no idea what voltage you need for it.

I'm afraid I am unable to help you any further with this issue as I don't know much about the AC side of the safrane. As I said previously I've always replaced the climate control panel when the SERVICE indicator appears however I've never had an AC pump that doesn't engage. Are you sure your pump is not actually broken? - The safrane can sense if the AC is working so if your pump is being activated electronically but the clutch is broken inside then the panel would still show a fault.. but you might think that it is not activating the pump instead of thinking the pump is broken.

CLIP is only as good as the faults it is designed to recognise, if there is a fault it does not recognise then it might become confused and show other faults instead. What it is telling you is that there is a fault with the AC system.. but it may not be accurate as to what the fault really is.

Of course always with computer fault finding systems you have to think what faults it can diagnose and how it does it.
Good thing about CLIP it that there's a list of all the possible faults it is able to diagnose. It also list a fault in clutch control.

Having a open circuit fault on pressure sensor seems pretty straightforward, there is no signal coming from the sensor to AC control unit. And if i assume my resistor thingy should work, there might be a fault in the wiring because it still didn't make the AC work.

Are there any other wires in the compressor than the clutch wire(s)? If not, how could the system detect a broken pump without trying to engage it first? Without wires there is no way to determine electrically if the pump is dead, but by actually trying to run it it would be possible to indirectly diagnose it as broken.

I guess i'll try finding that red wire for the clutch first and try forcing it to engage.

Maybe the CLIP isn't 100% accurate, but at least it is more accurate than an obscure "service" text on the control panel

To be honest I can't actually remember off the top of my head. There might be one.. a light brown colour.. but I may be confusing that with the alternator (dumb thing is I had the engine bay open a few hours ago ).

As for your second point, it wouldn't be able to - thats why I said don't trust CLIP too much. Sure it's a system with good intentions however it is french, made by renault and frankly... they're not known for being great with electronics.

Keep us updated, I will be interested to see how this dead AC is solved.

http://safrane.pl/ftpskp/Manuale/
as I already said... download the manuals, it's all in there.





thats for ph1, for ph2 its similar (minus+minus+stop for about 3 seconds), except if I remember correctly there is one more code (8 - on the right side it tells about presostat status, I don't know for the left). I don't have ph2 manual unfortunately (if you find one please share) so I have to use foreign forums with google translate. you can also reset AC system if that will make any difference - press rear window heater button + air recirculation button simultaneously for about 10 seconds - it will close all vents and reset the settings to factory defaults.

since I too have non-working AC (and no fault codes in this self-diag sequence), I'm interested in the outcome

The ph2 has a different control panel to the one shown in that image - and different buttons.



Does it still work? - Is it still the stop button for the ph2 or the sun button?

I will try that today and report the results.

Tested and confirmed to work!!! Note for any other PH2 owners: Press and hold both - buttons and the STOP button at the same time for about 3 seconds.

Mine came up with 3d on the right hand side - open circuit for the engine coolant temp sensor. That actually suggests a broken wire somewhere.. which would be why the cooling fans haven't been working for so long. Oddly though the temp gauge on the dash works..

I had the 8th code on the right side, and it was 8d, which is the same fault that CLIP says. No other faults.

I have heard that presostat sometimes fail on Safrane, so maybe start from there. I don't have any faults, yet my mechanic didn't get the compressor to work even by connecting it directly, so maybe its presostat and clutch in your case, and only the clutch in my case.



as I previously said, 3d code in 99% of cases means failed sensor. this sensor provides information exclusively to AC unit, so unfortunately it's not the reason for non-working cooling fans.