My 2007 seems much worse at hitting a desired temperature than a 2004 I was recently driving. Does anyone know if there is a part that can be replaced to make it behave? When I am driving on a cold day, I set the temp to 72 and I will eventually initially have heat. At some point I may go from comfortable to cold and I notice the vents are blowing cold air. I bump up the temp to 74 and it blows warm again... maybe for too long and then I bump it back down again. I feel like I am trying to hit a moving target. Anyone experience this and was able to improve the system? At times I wish I had the blue and red dial.
i just leave it on manual and change the fan to adjust heat. but maybe yours won't do that. i usually set it to 75f
I usually set it on full blast and highest temp till car warms up. This might speed up the process slightly... But in general in Winter you have to to drive for 20 minutes or longer before you can be certain you heater isn't working correctly.
I don’t have a problem with the car generating heat it’s just the way it regulates how it heats and cools after I’ve been driving for a while that seems weird
it's definitely weird the way you describe it. but idk what parts are involved. there must be a temp sensor and ecu. the ecu could be in the head unit or separate.
Have you replaced your cabin air filter lately? That's always the first essential step in this type of diagnosis.
I think there is a small air duct on the left side of the dashboard with a temperature sensor in it. The HVAC system uses that sensor to measure what the air temperature is in the passenger compartment. If that sensor gets covered by dirt and dust (pretty common), then it can't measure correctly. Also, if you have a scantool like techstream then you could monitor what the system is trying to do for temperature control, and if it is "overcorrecting" in some way when it shouldn't. Posted via the PriusChat mobile app.
That's good to know about the possible sensor location. I do have tech stream, but never installed on a PC. Maybe I need to get to that.
Yeah... I know the feeling... It took almost a decade of procrastination and failed install attempts to finally get Techstream going and I find I'm still unwilling to pull out that old laptop and use it when procrastination has taught me so many other work-arounds over the years.
