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W140 Scan Tool / SRS Airbag Light Scan Tool?

920 Views 18 Replies 8 Participants Last post by  MAVA
Have a SRS light on in my car after some work done. Set off the side airbag light it appears. What is anyone using for a diagnostic tool on a 1997 OBDII S500 W140 these days?
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00' E320, 03' E320T, 05' C230K
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I'm not versed in W140s........I believe your car may have a 38pin port. SRS codes will have to be read thru it and not the OBD II socket.
 

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I'm trying to understand if the 38 pin adapter is used in OBD-II vehicles. Some third party sellers of scan tools with 38 pin plugs say OBD-I cars only. Confusing.
I'm not exactly sure which models, there was a transitional period where some MBs had both. The OBD II was for engine diagnostic and the 38 pin port for others modules like SRS, ABS, ASR etc. My W210s and W208 had both.
 

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Discussion Starter · #6 ·
Update: had another garage help me out (multiple 10's of thousands of dollars in Autel/ Snap-On scan tools) and none would communicate. They called in a favor to another local German specialty shop who was able to clear the SRS light. They used the 38 min port under the plastic cover next to the coolant expansion tank.

For the future though, still interested in purchasing a pocket scan tool capable of diagnostics for this car! Any ideas, please reply.
 

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There are quite a few scanners that will work. It's very important to use the associated adapter cord. Generic 38 pin adapter cords will NOT work.

I have an older Autel MD802 that works for me. Others have been using Foxwell NT530 and the Autel AP200M / AP200 PLUS.
 

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The 38-pin connector and the OBD plug have been discussed and discussed.
On any W140, regardless of the year, the only way to do proper diagnostic is via the 38-pin connector in the engine bay. Period. If a garage is telling you otherwise, run away.

Also, of all tools available, only, HHTwin, the proprietary MB software that is part of Star SDS will let you see everything.

MAVA who is forum admin here used to say: Pay-to-play
 

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I actually have a Foxwell NT530 for BMW. Is there a 38 pin that will work with it to communicate with the car? Hopeful, but not realistic lol
Foxwell does have a 38 pin cord for Mercedes. You will also need the software for MB.
 

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I have a cheap 38 pin scan tool bought on eBay but it will only communicate with some of the ports. other ones it just won’t blink not even once so I assume it’s not communicating. too bad because exactly on the port 30 which is for the SRS system it won’t communicate and I also have the SRS light on after replacing the steering wheel and now need reset. :/
 

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I have a cheap 38 pin scan tool bought on eBay but it will only communicate with some of the ports. other ones it just won’t blink not even once so I assume it’s not communicating. too bad because exactly on the port 30 which is for the SRS system it won’t communicate and I also have the SRS light on after replacing the steering wheel and now need reset. :/
Reread post #7. Cheap scanner is not going to work. They will only read engine module. The 38 pin cable has only about three wires connected to the pins and is not fully wired.
 
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Have a SRS light on in my car after some work done. Set off the side airbag light it appears. What is anyone using for a diagnostic tool on a 1997 OBDII S500 W140 these days?
I have a 1998 S320 with SRS light on too. Have you found a solution to diagnose and/or reset the code yet? I've purchased 2 OBDII code reader/scanner both claiming that they work on SRS on BENZ, but neither was successful to connect to my car.
 

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I have a 1998 S320 with SRS light on too. Have you found a solution to diagnose and/or reset the code yet? I've purchased 2 OBDII code reader/scanner both claiming that they work on SRS on BENZ, but neither was successful to connect to my car.
I think you only can reset using Star diagnosis c3 via 38pin port. But in some cars if you’re unlucky even with the star diagnosis it will fail to communicate with the Srs airbag module and the light can’t be reset then you need to find out why. Easiest solution would be find someone or some shop which have the Mb Star Diagnosis c3 or buy a Chinese copy online but it’s a bit expensive. In my 97’ S320 for now I simply removed the Srs bulb until I find someone who has the Star Diagnosis.
 

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I think you only can reset using Star diagnosis c3 via 38pin port. But in some cars if you’re unlucky even with the star diagnosis it will fail to communicate with the Srs airbag module and the light can’t be reset then you need to find out why. Easiest solution would be find someone or some shop which have the Mb Star Diagnosis c3 or buy a Chinese copy online but it’s a bit expensive. In my 97’ S320 for now I simply removed the Srs bulb until I find someone who has the Star Diagnosis.
If its not communicating with SRS its the module and and not the Star. I had this issue with a 420, and after many after hours hours, my indy found that the module lacked ground, he rewired the ground in the harness and all was well. So if Star won't rest the light, you have other issues, and likely a safety issue as the bag may not deploy.
 

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If its not communicating with SRS its the module and and not the Star. I had this issue with a 420, and after many after hours hours, my indy found that the module lacked ground, he rewired the ground in the harness and all was well. So if Star won't rest the light, you have other issues, and likely a safety issue as the bag may not deploy.
you have said you can’t remember how he did it because it was 5 years ago anyways thanks for explain now I will try to check that module ground.
 
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