If the truck is parked and the speedometer is showing anything above 0, it is possible that which condition exists?

• A. The gauge is defective
• B. The fuel gauge is low
• C. The speedometer is accurate
• D. The engine is running

Answer: (A)

When a vehicle is parked, there is no wheel movement, so the speedometer should read zero. If you see any positive number while the truck isn’t moving, the instrument isn’t reading true speed. The most likely reason among the options is that the gauge itself is defective. A faulty speedometer can stick or drift and show a speed even when the vehicle is stationary.

The other possibilities don’t explain a nonzero reading while parked: a low fuel gauge has no effect on the speed indication; saying the speedometer is accurate would contradict the observed nonzero reading when there’s no movement; and the engine running doesn’t by itself cause a nonzero speed reading since speed depends on actual wheel movement.