Climate Control Changing Temperature

[john_in_nz]

Guys I've VYII Adventra and the Climate control system is driving me crazy. I have the temperature set at 20 and it's nice and comfy then suddenly it starts to pump in hot air and the car gets really hot. Even the missus who likes the car to be hot complains it's too hot.

I turn the temperature down to “C” and it cools down, then I select say 18 degrees and it ok for a while then it suddenly decides to pump hot air in again.

Any clues on what is wrong _ I've done a search and all the problems seem to be about the vacuum changing from one vent to another rather than temperature changes.

It also does the same thing when the climate control is switched from Auto to just A/C setting. recently we have been resorting to driving with the whole system turned off and just the roof open, but the same bloody thing happens no heat is coming from the vents then all of a sudden it decides to heat the car even though the heater/ climate control display if turned off.

The local dealer has supposedly fixed it by changing a sensor by the steering wheel but it still goes hot and he now reckons he has to pull the dash apart and replace the control module - his estimate was a couple of hundred for the module and then a day and half labour to install at their rate of $80 /hr I'm looking at over a grand to fix - Hence I'm not keen if there is a quick fix someone knows off

[KillerCV8]

My 2004 CV8 has just started doing exactly the same thing.

Climate control all OK, then all of a sudden switches to hot air and switches vents to the foot well.

However when I select manual control its stays on manual no problem, I have to leave the temp on full COLD or it blows hot air.

Seems a very similar fault. Stop and start the car a couple of times and all works well.

I believe there are multiple sensors through out the cabin, so it can tell the temp in the split zones for the climate control. Possibly one sensore throwing the whole system into chaos.

[danja]

The climate control is a pretty complex system which uses numerous sensors to decide what temperature air to pump into the cabin. There's a sensor in front of the radiator for ambient air, there's a sun sensor on the dash, an interior temp sensor, and others I can't recall.

If you take it to Holden they can hook up a Tech 2 and run a diagnostic test on it - might tell you what's going on. It'll be hard to fix yourself except by trial and error.

[KillerCV8]

Just replaced the interior temperature sensor (Retails for about $30.00 from your friendly Holden dealer.)

The Max Ellery manual is just plain wrong, Its not behind the radio/climate module as it says (probably is on a VT/VX.)

On a VY its actullay REALLY easy to get to, Just remove the two screws that hold insturment cluster/gauge surround out, pop the surround out and there it is, It vents throught the surround via the little holes you can see just above the steering wheel (to the left.) I always thought that was the 'beeper' for the instruments, Its actually the interior temp. sensor.

Swapped the sensor with the new one, its held in by one screw a rubber tube that goes to the HVAC unit and the two pin connector.

Problem seems to have disappeared, Will be taking the car to my brother who has access to a Tech2 system, hoping the climate has logged a fault code so we can confirm that was the problem.

Driving a few hundred kms this weekend so will be a good chance to test the climate.