MBforMikeM

My 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 occupancy 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? Or has anyone successfully used one of those Chinese emulators to diagnose the SRS light? Any help appreciated.

MBforMikeM

Did little testing, seat part removed from seat assembly.
Applied 12.20V to Red wire. The reading from the White wire coming back from the seat sensor read 12.11V and the Brown read 11.86V. I applied over 80# weight on the seat and there was no change in the voltage on the White or Brown wire. Does anyone know if this means that the sensor is faulty?

BryanW203

The passenger seat recognition sensor in a 220 is a very very common issue. If there is a fault for it, it is bad, just replace it no reason to diag further.

MBforMikeM

I have little by little come to that conclusion. My problem is that I took the car to the dealer who diagnosed the front seat adjustment problem being the $600 discounted seat controller was shot and the seat sensor was also shot. Guess what, there was a fuse missing and the seat adjustment works good now. Not trusting the dealer I ordered an Emulator from China for $19. Lets see if it removes the SRS light. If not I have to go back to another shop that can check the codes, gives me a print out and does it in front of me. I absolutely hate to have it done this way . If the emulator removes the SRS light I will order the $300 sensor and change it. I can do it in under 2 hours. That is $450/hour savings.
Thank You for your advice.

jnash

there is an aftermarket seat sensor emulator for like $35 if you google it. Ive seen it probably on ebay.

benzat17

please let us know how it went because im having the same problem so is my friend hes taking it to the dealer to find out whats the problem and fix it there i will tell ask about the voltage my dealer is pretty good and they'll tell me and asnwer any questions if i wanna do it my self

BryanW203

Thanks for the tip on the emulator, just ordered it for the gf's S430!

MBforMikeM

Bad news for me. The emulator did not remove the SRS warning light. The small light that indicates: Child Seat Airbag is not active, went on with the emulator all else the same. Drove the car for 15 miles. Maybe the one i ordered is not the right one. It came from Taiwan; Ecutool in 3 days. That was fast. Part was $19 and extra DHL charge was $30. I ordered the Type6 for W220, W163, W210 etc. years 2000 - 2005. this was the closest one I found for my W220 2006 S350. I guess it is back to the dealer or another MB authorized repair shop. Found one that would check the codes for $90. I live in Martin County Florida if anyone knows of a decent repair shop in my area.
For what it is worth: I checked the new emulator with an Ohm meter: red and brow=open circuit; no resistance, red and white=open circuit; no resistance, brown and white 20K-ohm resistance.

MBforMikeM

Once you get your Emulator, can you let me know which brand you bought and did did it work.

majorpeace

Benzer's

Please share the details of what your solutions are for this issue of the Child Seat Sensor problem. Many of us have the same issue as was stated by another poster.

Where did you find the Sensor. Company name, part number, payment method, website or link.

How did you install Sensor or Emulator.

What is the Emulator? Do it find the problem and diagnose or does it solve the problem. A picture would be great.

I have the problem and would like to solve it for my S500.

Thank you.

majorpeace

I also bought the Emulator from ECUtools China. It took 5 days to arrive and that was with the $30USD DHL express delivery.

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.

like2drivemb

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Dear majorpeace,

I just came across your quote regarding SRS (3 wire Emulator). I just got one from eBay (no instructions included). After reading your guide, I'm still not sure how to do it. Can you please illustrate - do I attact the emulator on the mat side or the connector from the (say car).

Would greatly appreciate your cooperation. Thanks in advance

andy220

Dear Gents,

I am also experiencing similar issue on W204. My SRS airbag led has started lighting. Airbag has not been exploded at all. I was advised to put some 100 Ohm resistor into cabling leading to seat occupancy sensor but it has not helped at all. Any advice would be highly welcomed. Thanks! Regards, Andy from Slovakia