Warning: By following this guide, you are bypassing a safety warning system. Remember to always wear a seatbelt when driving.

The fortwo 451 introduced a warning feature that notified the driver if the driver's seatbelt was not being worn. The passenger seat has no such feature. If the car is driven with the seatbelt not being worn, then an audible beep can be heard. This gets more instant over time. The seatbelt warning indicator is also displayed on the dash.

Where there is no legal requirement to wear a seatbelt (on private land in the UK), this warning may become annoying. We found this to be the case when moving cars around on the drive and produced this guide to turn off the warning system. It should be noted that this does not compromise the safety of the seatbelts themselves.

Disabling this warning system will not be an MOT fail as the testers never wear the sealtbelts when testing.

The sealtbelt warning system uses a microswitch in the driver's seatbelt socket. When the buckle is pushed in, it closes the switch. When the buckle is out, it opens the switch. Therefore we need some way of keeping this circuit closed.

When the circuit is open (i.e. buckle is out), the warning system is active:

Under the driver's seat is a blue connector that looks as follows. Take this apart by pressing in the toggle on the connector (big arrow). This will release the lock (little arrow). Now pull the connector on the left.

The connector circled is the supply is part of the main wiring loom. It is this circuit we need to close.

Use a small piece of insulated wire with 4mm stripped of either end and bent into a C shape:

Plug this into the connector and tuck this under the seat. You have now permanently closed this circuit and disconnected the microswitch on the seatbelt buckle socket.

The car will now think that the seatbelt is always plugged in.

To put back to normal, simply pull the little wire out of the connector and reconnect to the microswitch wiring (picture 2 in reverse).