Peugeot 207 1.6 VTI 120 (EP6) - Thermostat Housing and Air Conditioning - James B


I found the site while looking for an answer to a question relating to an issue with my air conditioning.

My Peugeot 207 1.6 VTI 120 (EP6) has had the error code P0599 for a few months (stored but not bringing up any errors - according to Planet Peugeot, it is an intermittent fault generated around 2500k revs). As the weather in the UK generally doesn't require the air con, I hadn't noticed that the air con did not blow cold. When testing the air con, I noticed it blew warm, so took it for a refill and that didn't sold the issue. Driving home, the air con started working and worked for 3 days after (admittedly the car hadn't been driven after being parked the night it started working). When I went to take the car out again it didn't work. The garage initially thought it was the relay, but that comes in a sealed unit on this car and the sealed unit is £300.

I hooked the car up to my diagnostic software and cleared that fault only (as it was the only fault displaying, but I only selected to delete that error code, in case there were other stored codes that were not displayed on the phone app). I turned the car off and turned it on again and I heard the click of the air con kicking in and it worked perfectly.

My question is, on the Peugeot 207 1.6 VTI 120, does the Thermostate Housing affect the air conditioning, or is it just a coincidence that the air con started again after clearing that single fault?

Sorry for the long post, but I wanted to make sure I supplied all the facts.

Thanks in advance.



Edited by James B on 04/08/2013 at 00:15

Peugeot 207 1.6 VTI 120 (EP6) - Thermostat Housing and Air Conditioning - elekie&a/c doctor

Most modern cars use the engine coolant temp sensor to provide info for the engine control unit and others,including the a/c climate control system.If a fault is detected or the coolant temp becomes excessive,then the a/c system can be shut down to reduce any load on the engine.I would check the connections to the coolant temp sensor on the engine and also check to see if the sensor has a slight leak through the connector pins.It is not unknown on these for coolant to rise up into to wiring and eventually find its way into the engine control unit.(capilliary action).hth

Peugeot 207 1.6 VTI 120 (EP6) - Thermostat Housing and Air Conditioning - James B

Thank you very much for this. I checked Planet Peugeot and it states the thermostat housing gets stuck to open at 2500K revs. I assume this explains why the air con blows slightly warm when turned on (when the fault code is registered)?

I will get the connections checked out and then replace the thermostat housing.

Thanks again for your help.

Peugeot 207 1.6 VTI 120 (EP6) - Thermostat Housing and Air Conditioning - Skinhead

My 207cc (1.6 petrol VTi auto) had the same problems for months. It went it for a regas and service (used losely) and after a few months the a/c would work for a few days then cut off few a few days then come back. After taking it to the local garage to have it checked they couldn't find nothing wrong with it as the a/c was working at the time.

I sort of got fed up with this and ended up taking it to Peugeot who quickly diagnosed the fault as the thermostat housing. There is an error code that shows up P4099 or similar but this will not show up on the cars check thing on the dashboard readout.

My neighbour has a diesel model 207 and like mine it would appear the tell tale sign of a failing thermostat is the a/c or c/c will work for a while and then cut off as the thermostat housing has a sensor that tells the fan to swith off and kill the power to the compressor. This inturn makes the a/c go instantly warm even with a low ambiant outside temperature. Also the sign of a failing thermostat (common to my car and his) is that even when the a/c is on there is a blast of warmer air coming though one or all of the vents even though the temp setting is on "Lo" or in the blue.

Fortunately the car has a warranty on it as it would of cost over £650.00 inc the diagnostic.

I think the word of caution here is that if the ac is failing don't take it to a "cheapo £35 regas" garage, have it checked out by a dealer. Also mine was not full filled up with gas and was indeed half full despite what the non Peugeot garage said.

Hopefully this will solve the problem.


Value my car