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 american US version models with WSS system, rarely there may be different wires colors)
Below there are photos of the versions. The photos were taken under passenger side seat.