Climate control: Temp sensor failure?

[Jaz]

The past week when the ambient temperature outside has been >25deg my climate control has decided it needs to blow hot air on me when I've got the temp set for anything higher than 18.0 deg, even at 18.5 it blows HOT air on you. I'm sure you understand that this is not that nice.

I cleaned the little grille covering the internal sensor with a brush, but it's no better, and I also cleaned the outside sensor, for what it's worth.

Has anyone encountered this before? Any suggested fixes? Has anyone pulled that segment of the dash and cleaned the sensor with success?

[LOWLIB]

probably pointless and i don't mean to be rude,

but have you got the A/C turned on?? like the actual cooling button selected.. I used to do it all the time in our work vans because the indicator light was blown an i wouldnt know if it was off or on

[Jaz]

probably pointless and i don't mean to be rude,

but have you got the A/C turned on?? like the actual cooling button selected.. I used to do it all the time in our work vans because the indicator light was blown an i wouldnt know if it was off or on

Thanks for the response, but I had checked that. It does still blow cold air as required, but only when temp is set very low.

[arrow224]

AC button off: temp set above 23, blows increasingly hotter air as temp rises. Normal. Temp set below 23, will blow sort of warm air. Will depend on temp inside the car, as well as any windows opened.

AC button on: temp set above 23, blows increasingly hotter air as temp rises. Normal. Temp set below 23, will blow cooler air as temp decreases.

When on Auto mode, any temp set below 25 will start the AC.

This is how it is in my 07 Premium single zone.

[jp928]

This is similar behaviour to that in my 928, when one sensor is out of circuit - at min temp setting, ok, but as soon as its off Min, you get full heat. You would need to be able to check you have a circuit across both sensors, and that the control unit can see them both. On the 928 I could tell you where to look, but not on the suby. Get the wiring diagrams from somwhere, then work out physically where the connections are, and test the circuits.....I would try to find the sensor under the little grille, and check that its not open circuit as a starting point. There was a post once on legacygt.com about putting a tiny fan on the sensor so it had airflow over it - without airflow it can be reading stale air under the dash at a different temp from what you experience - the 928 has a fan for this reason.

jp 08 gtb 6mt.

[Jaz]

Well I pulled the dash lower facia off, found the connector to the sensor disconnected, so I reconnected it.

Unfortunately I also did something else unrelated, and have a CEL so I've not wanted to test it.

[jp928]

No gear with which you can get the codes out? On my 05 outback there was a method - under the driver fuse box cover there were 2 white connectors - join them, turn it on, and press the trip reset twice quickly, and the dash would show codes for each area (if any), changing area each trip reset press....see if this works for your model - web search etc...Unless you have an ecudatascan, or an OBDII tool....Garmin with an Ecoroute?
jp 08 gtb 6mt wagon, with all of the above.

[Jaz]

No gear with which you can get the codes out? On my 05 outback there was a method - under the driver fuse box cover there were 2 white connectors - join them, turn it on, and press the trip reset twice quickly, and the dash would show codes for each area (if any), changing area each trip reset press....see if this works for your model - web search etc...Unless you have an ecudatascan, or an OBDII tool....Garmin with an Ecoroute?
jp 08 gtb 6mt wagon, with all of the above.

Yep searched many times from different angles and can't find the connectors there, so maybe they disabled that feature on a MY07

[jp928]

Try this one
http://legacycentral.org/library/literature/codes.htm
There are several posts , but all boil down to the same as this one - connect black cables, turn ON, watch CEL light. I remember a different process on my 05 OB, but cant find it now. Sounds similar to this one.
I am in melb, and have an ECUdatascan I could use, which was originally built for Subies, but also works on Holdens and SAABs from personal use.
jp 08 gtb 6mt wagon

[Jaz]

Try this one
http://legacycentral.org/library/literature/codes.htm
There are several posts , but all boil down to the same as this one - connect black cables, turn ON, watch CEL light. I remember a different process on my 05 OB, but cant find it now. Sounds similar to this one.
I am in melb, and have an ECUdatascan I could use, which was originally built for Subies, but also works on Holdens and SAABs from personal use.
jp 08 gtb 6mt wagon

I just spoke to my mechanic (gotta love facebook) and he told me you can't do the cable connect thanks to the fact that MY07 onwards is OBD2 which has four digit fault codes.

[jp928]

Yes, I went and looked at my fuse area, and there is nothing there that might do as in the previous models. I think you need a proper OBDII reader (cheap ones on ebay). Note that usually, if the error was a one off, the CEL will go out after 5 or so starts and there is no more error problem. Maybe ask for somebody in Brissy with one....EcuDatascan, or similar.
jp 08 gtb 6mt wagon