Climate control wierdness

[Viking]

Hi all,

I've done a search through the forum and can't find any posts relating to what I'm seeing.

Given it's winter here in Melbourne (and freezing cold), I like to be toasty warm when I'm driving. Except that the climate control decides to start blowing cold air after a while, even if the temperature dial is set to 24 degrees.

I know it's not that warm inside the car, so the CC is not doing a "Oh, I'm too hot now. Time to blow cold air and cool things down." routine.

Has anyone else seen this? If so, what did you do to fix it?

Cheers,
V

[himynameisdaniel]

Does this happen at also at night?
Does this also happen when at say 30 degrees or max?

The Climate control A\C is fitted with an internal temp probe and a photo sensor.

They work together to adjust the air outlet temp.

If this is something that happens quite often and or you can replicate the fault easily consider getting some duct tape and placing it over the photo sensor completely.
It's a little square thing in the middle of the dash where the windscreen intersects.

See if the fault goes away and then remove the tape and monitor again for a long duration of time.

Should the fault re-occur after removing the tape then you would have narrowed down either the photo sensor or A/C ECU being the fault.
If there is no change it may indicate an issue with the cabin temp sensor or actuators or AC\ECU itself.

You can ask mitsubishi to perform resistance tests on the temp sensors with the MUT III but ultimately you would need to be able to replicate the fault for their techs to understand.

[Lancer1993]

Yeah sounds like a a sensor issue.

The only time I had an issue was early morning when it's cold, the demister wasn't doing what it should, needed to set it to manual to clear.

Do you have a dash mat which might be covering the sensor or have you covered the one to the left of the steering wheel?

[Viking]

Thanks for the quick replies, guys.

To clarify what I mean by "cold air" - the air coming out the vents is not freezing cold, but it's not as warm as I think it should be (as if it's just puling fresh air into the car without heating it first). Turning the temperature dial up doesn't seem to make any difference.

There is no dash-mat or anything on the dash, so it's not a blocked daylight sensor. As for whether it happens only at night, or only during the day, I haven't taken any notice.

It usually seems to happen after I've been driving for a while, and the car is getting to a comfortable temperature.

Where does the temp sensors hide? I'm wondering if it's getting warm somehow.

I'm taking the car in for the drive belt recall in the morning (and then out tomorrow night), so I'll take note of what happens.

Cheers!

[himynameisdaniel]

I guess it depends on how much "cold air" you are experiencing and how often but it could also be a classic symptom of air in the coolant system.

[Lancer1993]

Maybe the cool air is a Mitsy safety feature, to keep you alert

[Viking]

Hmmm. Stranger and stranger.

Drove around tonight with the temp set to 25. Lots of lovely warm air, no cold air. Turned the temp down to 21, got cold(er) air, as you'd expect. Turned it back up to 25 and got warm air again. No cold air at all.

Maybe I need a longer drive for this issue to raise it's head? That'll have to wait until Thursday night.

As for air in the cooling system, the coolant level in the overflow tank is OK. Wouldn't air bubbles (vapour lock) mean a huge spike in engine temperature? I haven't seen anything like that at all.

[Lancer1993]

It would be vary rare to get a vapour lock in the cooling system of the engine, I'm never heard of it in a modern car.

[Lancer1993]

I just leave it on Auto most of the time then adjust the temp as needed.

[Viking]

I think it's just me over-reacting to the CC turning the heater off.

I have the vents blowing the warm air onto my hands (because they always feel cold for some reason). I think that when the warm air stops coming out, the cooler air feels colder than it really is.

[Lancer1993]

I wouldn't worry too much, maybe make a note for later reference if it comes up again.

[powermad]

I've noticed the same thing on our 2015 model. Agree with your theory it's just the heating off seems to produce "cold" but it's not cooled, just normal air temp. In the morning here 23-24 blows warm air, but in the evening at that setting it's cool air. As others have said, I just put it to 25-26 in the evening and it's then warm.

[Lancer1993]

It's usually warmer in the evening so it will blow cooler air, it was cool here yesterday and I had to drop it down to 20 for a short time so I could get some cool air. I hate a car that's too hot inside.