The seat occupancy sensor in most new Mercedes models may have 2, 3 or 4 wires:
- white, red, brown (3-wired mat)
- blue, brown, black (3-wired mat)
- black, black (2-wired mat)
- white, red, brown, green (4-wired mat in some models with WSS system, although wires colors may be different in case of the 4-wired seat mat)
Below there are photos of the versions. The photos were taken under passenger side seat.