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Faulty climate control

JimX

By JimX,
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JimX Grand Master

JimX

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Ok my climate control is faulty, so how do I fix it? I did the diagnostic and it flashes up 25 (sunload sensor) and -26 (PBR). I don't know what the PBR is, and I don't know why it flashes up with a negative symbol.

Can someone tell me how I would fix both of these things?

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JimX Grand Master

JimX

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Oops I forgot to describe the symptoms. At night the climate control is still cold, even when set to 32 degrees. Well it's slightly warmer when set to 32, but still relatively freezing. If I turn the a/c off, it starts to warm up slightly, but still nowhere near 32, and of course then the glass fogs up because the a/c is off. So I'm doing an endless adjustment of the climate control between keeping the temperature right and the fog off the windows. It's annoying to say the least.

Thanks for that info 2fardown, I didn't think to put it in the sun to try it. Maybe it's fine, so that would leave the PBR I guess? Hmm.

predator Grand Master

predator

Posted
Posted

er yeah.. sounds like possibly stuffed vent control.

When i pulled it all apart, worked out roughly how it works.. heater is constantly on, (although there maybe some type of control from the engine side via controlling the amount of coolant/heat going to it), basically fan blows through aircon, and there is a flap in the heater box that opens and closes. Depending on the amount of heat or cool to give you xx degrees, the flap is either full open or full closed, or somewhere in between.

Therefore it *sounds* like your flap is stuck on full close, just letting aircon through.. It could also indicate a possible electrical fault in the eCU or rest of the wiring somewhere meaning the signal to "start heating" or 'start cooling" is stuffed.

Anyhow, have a play and see what you discover.

JimX Grand Master

JimX

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Well I ran the second test which is meant to test the mode doors and they all came up ok. I could hear them moving around so I'm pretty sure that's not it. It just seems to have difficulty in determining the temperature.

I'll try the test again in sunlight and if that clears but I still get the PBR error I guess I'll have to look into it further. Otherwise buggered if I know what's wrong.

sewid Grand Master

sewid

Posted
Posted

It could be a fault with the internal temp sensor. This is located in the dash below the gauge cluster. You can see it because it draws air in through a vent. There is supposed to be a hose connected to this vent which commonly goes missing when people remove the dash fascia.

inside the vent is a temperature sensor which is always getting really dusty. Spray some electrical contact cleaner on it after removing as much excess dust as you can.

Ill try to find a pic.

GTR R35 Proficient

GTR R35

Posted
Posted

Another suggestion is to see if the heater core is blocked. Run the car to operating temp.

You should see 2 water hoses running into the cabin (not aircon) they both should be hot. if only one is hot, then the core may be blocked. just a suggestion :0-)

Ta

Mal

JimX Grand Master

JimX

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Posted

I spoke to someone that knows more about this thing, and they reckon that there is a valve in one of the hoses that often plays up. He reckons that this is more likely the cause than a blocked heater core. He said that it was on the inside of the firewall where one of the heater hoses comes in. Aside from that though I don't have much of an idea of how to get it out or replace it. Does the dash need to come out? Anyone with experience and/or photos please help!

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