As most know it's been colder than a witch's teat here for a while now.

We had about 6" snow in very cold temps followed by a big melt some rain and then slam back into the deep freeze.

This left the roads mostly clear but a lot of water is still frozen in very small amounts on the car.

So it just utters a solid beeeeeeep when I select reverse.

Too damn cold to check much of anything out but what's the likely cause?

Sensors seem very clean & clear.

 

If the tone lasts about 3 seconds, that's telling you that at least one of the sensors isn't working. With the car OFF, but ignition on, select R and listen at each sensor. You should hear a clicking if it's working.

 

Today it "warmed up to 22F from 12F yesterday so by the afternoon this issued stopped.

Nothing could have melted so it's just weird ...

 

There was ice in or on one of the sensors. Happens on almost all cars up here during the winter.

 

Nothing actually on them on the visible side and the high temps the last 3 days were 6F, 12F and a whopping 22F yesterday. The car wasn't driven very much either, two 10 minute runs at the start and end of the day. So if it were ice how did it melt?

Weird ...

 

As I said, next time it does it, have a listen to the sensors.

 

The tone is not 3 seconds it's non stop.

It's balmy here this morning 25F not peep today.

Personally, I think the car was just whining about how cold it was ...

But now it's catching. This morning all 6 smoke detectors wen off in my house and none indicated that IT was the one who started the cacophony. Since they all have battery backup as well a power on/off at the breaker panel has no effect. So I had to pull each one out of the ceiling and physically disconnect it.

It's too damn cold here!

 

It doesn't take much for a sensor to convince itself there's something there. Ice might have 'sublimated' with no visible dripping. My SUV is black and sits in the sun. Even though it's well below freezing, it clears itself of ice and snow long before the lighter coloured cars do.

 

Agreed. Some of these back-up sensors have been known to activate from nothing more than a relatively heavy rainstorm....