The easiest way to test if a four-wheel-drive system is working is to accelerate briskly from a standstill, ideally on a slippery surface. Ensure any traction control systems are deactivated and if the four-wheel-drive is operating correctly you should experience very little wheelspin. However, if it is not working either the front or rear wheels will spin, depending on the vehicle.

An alternative to this is to have the vehicle raised up on a vehicle lift and engage first gear with the engine idling. The supplying garage may see this as a preferable alternative to the first option.