My MB S350 2006 W220 SRS light has been on for a couple of weeks and passenger side front seat adjustment did not work. Took the car to the dealer and got a diagnosis that the seat module and the child seat/passenger sensor are fried. $2300 to fix them both. Decided to diy. Found out that fuse #66 was missing, put a new one in and the seat adjustment works. SRS still on. Now I have my s350 2006 W220 Passenger seat on my work table. I would like to know about the resistance for the front seat occupany sensor before I pull the upholstery off. Everything looks nice and clean and if there is a broken wire or connector I guess I should not get any reading on the Ohm meter?
I have seached around the forum and here seems a good solution to the problem.
There is an aftermarket seat sensor emulator for like less than $15 if you google it.
I also bought the seat occupany Emulator from obdii365.com China. It took 5 days to arrive and that was with the cheap $11.99 USD (shipping included) DHL express delivery. This one is for ALL W220 models only. If you buy the emulator make sure that you solder the circuit pads as directed on the web page. It should work. My wires were not consistent. The emulator has 3 wires (red, yellow and black) these should be connected to the yellow connector that attaches to the Child Sensor Mat and also has 3 wires (red, brown and white). Red Wire emulator (B+) - to Red Wire (connector) Black Wire emulator (Ground) - Brown Wire (connector) Yellow Wire emulator (Line) -White Wire (connector) You have to cut the wire from the Child Sensor Mat and splice them to the emulator. Then re-insert the connector under the seat in the same location. you can tape the emulator to a location under the seat that will not get disturbed when the seat is moved back and forth. You will need to have the code reset.
Hope the solution for this issue of the Child Seat Sensor problem help many of us have the same issue.
Ps. Choose the correct emualtor for your MB model. Mine is for W220 only. Other models should go for these: