A mechanical engineer, a chemical engineer, and a computer engineer are driving along a desolate desert road on a scorching hot day. Their car suddenly spotters, and stalls out.
The mechanical engineer mutters something about the carburetor jamming up. He gets out, and pops the hood to take a look.
The chemical engineer mutters something about vapor lock in the gas line. He gets out, and crawls under the car near the gas tank to take a look.
The computer engineer was behind the wheel driving. He sits silently, as if lost in thought.
Finally he yells "wait a second guys, I've got it!". He opens the door, steps out of the car, and closes the door. He opens the door again, gets behind the wheel again, and turns the key.
The car starts right up.