Service Light and Heat Inside Car at Same Time

[Orchid Girl]

Pulled out into traffic and immediately began feeling high heat as if my heater was on. I looked and found that it was not on, and in fact was in the A/C position, but not turned on at all. I also noticed at the same time that my service light (not the check engine light) was on. After a couple of minutes the service light went out, and the heat started dissipating at the same time. This happened twice today. Any idea what it is about anyone? I own a V40 Station Wagon (2004).

[alschnertz]

I suspect the two items are unrelated.
Your owner's manual spells out how the Service Light is supposed to work. It sounds like it is working the right way. Check your owner's manual.

What positions were the dials in? Again, if you reference your owner's manual, you may find out what's going on.

[Orchid Girl]

I'm pretty sure it's the thermostat and/or the ECT Sensor. One thing I didn't think to check yesterday was the temperature gauge. I'll be out driving it this morning and checking that also. After watching this video, it looks like something that I can do by myself if indeed the thermostat needs replacing.

Thank you

[alschnertz]

I've done the thermostat on my '01 and yes, it is pretty simple.
Decent video you found.

I wonder if your ECT is bad though. You didn't get a Check Engine Light, did you? I thought you said the Service Engine Light.

[Orchid Girl]

Yes, only a light that said "Service." Just the one word, not "Service Engine."

Drove it around for a couple of hours today, highway and freeway driving, but the temp gauge was fine and I never did have the problem with the heat again. I'm going to reset the Service light and see if it comes back on because I shouldn't need service yet.

[alschnertz]

I'd do the same thing with the service light reset and then wait to see if there are heat-blasts again before replacing parts.

[Orchid Girl]

Thanks for all of your thoughts Al. I appreciate each one