RAY: At our shop, we have a scan tool. This scan tool is designed to plug in under the dash or under the hood of the car and extract valuable information from the car's computer.

TOM: So we can misdiagnose the problems.

RAY: Exactly. Recently, we got a new piece of software for our scan tool. One of my guys had plugged the scan tool in, and was looking for readings that indicated a problem. For example, if it says the engine operating temperature is minus 40 degrees, you have some idea that there's something wrong with the engine's temperature sensor.

He was scrolling down and looking at all the information, when he came to a reading that said, "air pressure low right, front tire."

He said, "Huh?!" So, I walked around to the right front tire and sure enough -- the tire was almost flat and I said, "It's right."

The question is, how did the scanning tool know that the right front tire was low on air?

[ Car Talk Puzzler ]