[WatchcamE430]

Hey all,

First off thanks for this great thread.

Before you go out and buy the sensor just try and check the condition of the lead 3 wire from the sensor. I removed the front part of the seat cover but left the back still on - while I tested. My brown wire had a fault and it was in a tricky spot. Past where the zip tie that lashes the wire to the seat frame - but just before the hole in the seat mesh / seat bottom. From the naked eye it looked fine - but it had broken - so test. I know I almost gave up but thought as long as I am in here.

I used a razor blade to carefully cut away the protective sheathing that covers all three wires and then used the blade again to carefully expose a small amount of wire to check for any loss in continuity. First I checked the white and it was fine then brown and it was the culprit.

Some tight spot soldering but in the end that did the trick and the light is off. There is no resetting or doing anything else - all good now. Ohh I did put protective tape on the metal hole where the line was cut and also put some sheathing on the brown and then the 3 wire.

It took me an hour and a half and I would not consider myself a mechanic - fairly handy with some tools but that's it.

Cheers,

Eric

Did you disconnect the battery out of interest? Guess with ignition off it might not have power anyway?

Also .... Have you seen the seat sensor bypass boxes you can buy? It keeps the airbag system activated and is plug and play.
Why would i not fit one of these?

 

[mb2501]

Many thanks to MRBSMITH for the excellent guidance on how to replace the seat sensor. It kept me from going down a number of blind alleys. I would like to add some details and comments that I noted for the next time.
Step 1. I had the codes read by the local dealer (code B1315), and of course, received a quote of $220 for the sensor and $348 to install it.
Step 2. Great idea to gather everything first. From MB of Cincinnati I ordered a sensor (210-821-21-51 for a MY2000) for $144 plus shipping. I would add an E12 external Torx ® socket and a few tie wraps, black if you’re fussy.
Step 4. My yield was only a quarter ($0.25) and my wife’s favorite crochet hook (priceless).
Step 5. Defer this until after steps 6 and 7, at least for the power seat connections. You may need to move the seat in order to access the bolts and the seat belt attachment.
Step 10. Place protection on the carpet in front of the seat.
Step 11. Remove the connector laterally as shown in the picture, not axially.
Step 12. Unsnap and remove the fabric covered spacer piece. The outside cover is fastened with a screw at the back and is hooked at the front. The inside one is hooked at both ends. Bend it to release the back one first and then slide it forward to free the front one.
Step 13. Add “On both sides” at the beginning. Also loosen the rear bolts considerably in order to allow the seat frame to pivot upward.
Step14. If you have no assistant, lean on the seat with your chest, leaving your hands free to pull out the bar. Pivot the seat frame upward and clip tie wraps as needed. The top of the cushion frame fits in a groove in the rubberized fiber cushion. The cushion needs to be separated from the frame in order to gain access to all of the butterfly clips, and to ease the unwrapping of the leather cover over the cushion. Note that part of the cover assembly is a white fabric that is sewn to the leather and lies between it and the rubberized fiber.
Step 17. Well, there is a tricky part here, and that is attaching the wires in the fabric sleeves on the underside of the cover to the butterfly clips. I first rotated the clips back to their original orientation, then folded the cover back on itself from one side. Rather than use a long screwdriver I used a shorter one, and ground a notch in the blade tip. I was able to grab the wire in the sleeve with the notch in the screwdriver and push it into the groove in the cushion just adjacent to the clip. A satisfying “snap” can be heard, letting you know that you’re hooked up. It helps to hold the back of the clip with one hand and to work from the rear clips to the front ones. Pull the white fabric taut over the cushion and then the leather. Insert the frame top back into the groove in the cushion, etc. Before assembly of the fabric covered spacer to the seat, clean it with a lint roller and then upholstery cleaner. Also, clean at least the sides of the leather cover before reinstalling the seat. The SRS light is now out!

 

[MRBSMITH]

Great. Tips

Indeed, thank You, and all who have helped.
B

 

[ME320BENZ]

I have the same problem.

I am having the same problem. I am going to try checking the wires first. First I had the light only come on when a person sat in the passenger seat while driving it would come on and off. Then it would come on when a passenger sat there and stay on till the passenger got off. Now it stays on regardless if there is a passenger or not.

 

[ME320BENZ]

Its a two man job I am struggling with my daugther here.

 

[ME320BENZ]

3 men would be best.

 

[ME320BENZ]

After countless hours I looked at the sensor and saw a break in the wire right after the white box. So I decided to split the wires and replace them with 3 new wires. I put everything back and the SRS in the dash stays on but the air bag off light where the shifter is off it used to stay on. Don't really know if its working. Does the SRS light in the dash needs to be reset? If so how??

 

[mbvis]

As I recall, the SRS light flashes after engine started then goes off. Buckle up to see if it goes away. You need to test the light with all scenarios (engine off, key in position#1, #2, engine running, ...)
Anyway, I was looking at page 1 thinking I could use the steps to put some cushion to the sagging bottom, but it looks like too much work.

 

[ME320BENZ]

As I recall, the SRS light flashes after engine started then goes off. Buckle up to see if it goes away. You need to test the light with all scenarios (engine off, key in position#1, #2, engine running, ...)
Anyway, I was looking at page 1 thinking I could use the steps to put some cushion to the sagging bottom, but it looks like too much work.

Ill try the buckle up. I know it need to be reset. I will get one of those SRS resets from ebay. They are about $20 and over.

 

[KarlBenzSF]

I am getting stucked on the first step.. those bolts are so tight... :-(

 

[umakegoodcookies]

The yellow plug on the front of the seat, that's the wires coming from the car right? Is the jack from the seat and the plug from the car or is it the other way around?

 

[MRBSMITH]

Still going strong after all these years...

The wire is to the car, the fixed plug is to the seat, again try and fix/replace that short wire, but take your time and get it right.

This post just keeps on going and going. I am so happy that so many have contributed and found it usefull.

Keep on DIY ing.

B

 

[Mr.Billy]

The thought occured to me,

Hey folks -- just wanted to post this photo of the SRS sensor pad that is used on some early W210 models. It is part number A 2108207810.

In North America, the EPC says it is used on chassis codes 210.020 (E300D) 210.055 (E320) 210.072 (E420 and E50 AMG). Most likely, it is only used on the very earliest years of the W210 (1996 and 1997) and maybe some later years.

If you have a prefacelift car (99 or earlier) make sure you ask your dealer for the right part with your VIN or check for the right part yourself in the EPC. You can also possibly tell by looking at the connections on the bottom front of your passenger seat. If you don't see a yellow connector as in the photos in the steps of this DIY, then you probably need this part.

Also, if you don't have a switch/light for the airbag next to your shifter, then you probably don't have a yellow connector and you probably do need this part.

that I have not seen people question regarding this procedure. I have a 97 300D like this post is talking about. It has 2 wires in the sensor. I am assuming this is a passenger present sensor?? When the passenger is sitting on the sensor I assume it goes from open to Short? The reason I ask this question is my SRS sensor is on and I do not have passenger present lite. I do not care about saving my air bag if nobody is sitting in the passenger seat in the event of an accident. I want to jump this sensor to make the car always think someone is sitting there. If the airbag goes off in the drivers seat the car is more than likely a write off anyway. The other point is the 97 the air bags are probably past due date at this point.
Does anyone have the electrical drawing for a Early w210 SRS system, and maybe a functional spec? .
More than likely with a 2 wire system, it's not open or short. You probably have a higher resistance without a passenger, and a lower resistance with a passenger. First I don't know what is causing my SRS light, If it is a resistance it's looking for, I would like to see in the diagram, where I could solder in a resistor. Has anyone came up with a bypass plug or jumper?

Best regards,

Bill

 

[Mr.Billy]

I guess I should have read all the post

Did you disconnect the battery out of interest? Guess with ignition off it might not have power anyway?

Also .... Have you seen the seat sensor bypass boxes you can buy? It keeps the airbag system activated and is plug and play.
Why would i not fit one of these?

through page 10. After reading the first 6 pages, I responded to a post of my early w210. I really looking for a by pass plug like your talking about for my 15 year old w210. One that keeps it activated.

Can you tell me where I can buy one, or whats involved to make one myself

Thanks,

Bill

 

[zettma]

Thanks everyone for the info. After over five years of having the SRS light on it is finally fixed. I put a new sensor in the seat today. It was very easy with the directions. I used a long ratcheting wood clamp and a board across the seat to compress the seat cushion. It worked great. I also had some good father son time with my 17 year old son. He gets his license this month so I wanted to make sure it was working. Have a great week all.

MAZ

 

[WatchcamE430]

through page 10. After reading the first 6 pages, I responded to a post of my early w210. I really looking for a by pass plug like your talking about for my 15 year old w210. One that keeps it activated.

Can you tell me where I can buy one, or whats involved to make one myself

Thanks,

Bill

Hi, sorry hadnt seen your question. There are a few on ebay but i am not sure they are a good idea. They make airbag system think someone always sat there which might not be a good idea if you had a child seat?

 

[Eastb]

Final got around to fixing my SRS light. As others have mention in this post, the problem was a broken wire. The idiots at MB zip tied the wire to the seat pan so that there was no slack between the pan & sensor. So every time someone would sit in the seat it would stress the wire. I knew right away where the problem was. In fact the outer jacket was split right at the zip tie.

Anyway it was a major PITA to repair the wiring harness. Not for the faint of heart. I had to cut the wires right at the seat pan hole. I then had to solder the wires together with about an 1" of wire hanging out. I cut the jacket back far enough so I could slip some shrink tubing over each wire. It was a bitch. I about gave up on the repair. BTW checking the resistance aint easy either. For starters the resistance is very (left me scratching my head) high, I measured M ohms. I was expecting much lower resistance. Could have been because of smallish pins in the connector plug.

The E55 multicolored seats are a little tougher chore to disassemble. I did not remove the leather ( would have made life easy) cover. I couldn't freaking figure out how to get the damn cover off! I thought about totally disassembling the seat.

Thanks to all that contributed to this DIY it saved me lots O $$$!

 

[WatchcamE430]

Final got around to fixing my SRS light. As others have mention in this post, the problem was a broken wire. The idiots at MB zip tied the wire to the seat pan so that there was no slack between the pan & sensor. So every time someone would sit in the seat it would stress the wire. I knew right away where the problem was. In fact the outer jacket was split right at the zip tie.

Anyway it was a major PITA to repair the wiring harness. Not for the faint of heart. I had to cut the wires right at the seat pan hole. I then had to solder the wires together with about an 1" of wire hanging out. I cut the jacket back far enough so I could slip some shrink tubing over each wire. It was a bitch. I about gave up on the repair. BTW checking the resistance aint easy either. For starters the resistance is very (left me scratching my head) high, I measured M ohms. I was expecting much lower resistance. Could have been because of smallish pins in the connector plug.

The E55 multicolored seats are a little tougher chore to disassemble. I did not remove the leather ( would have made life easy) cover. I couldn't freaking figure out how to get the damn cover off! I thought about totally disassembling the seat.

Thanks to all that contributed to this DIY it saved me lots O $$$!

Do you have any pics for any chance of where the damage was?

 

[Eastb]

Oh geez, I ment to take pics of my repairs. My bad. The seat removal was straight forward and easy. Once out locate the conductor and you;ll see the hole where the wires go the through the seat pan. MB had zip tied the sensor multi-conductor wire to seat pan with no slack, no room to move with the cushion. Really poor workmanship. It was a no brainier. I'll bet there are plenty of other seats that have been done the same way. It's attention to detail...epic fail. How may $ have been spent replacing the sensor when I'll bet most failures are broken wires...

 

[WatchcamE430]

Oh geez, I ment to take pics of my repairs. My bad. The seat removal was straight forward and easy. Once out locate the conductor and you;ll see the hole where the wires go the through the seat pan. MB had zip tied the sensor multi-conductor wire to seat pan with no slack, no room to move with the cushion. Really poor workmanship. It was a no brainier. I'll bet there are plenty of other seats that have been done the same way. It's attention to detail...epic fail. How may $ have been spent replacing the sensor when I'll bet most failures are broken wires...

Just thought I would check, sounds like it will be obvious when I probe under there!