Anyone in NoVA/DC with scanner to clear W210 SRS light? - PeachParts Mercedes-Benz Forum

pjc · #1 10-18-2016, 08:46 PM

Before I drop a small fortune at my local dealership or indie for 5 minutes work, is there a forum member in Northern Virginia or DC with a high-end scanner that can clear the SRS code? Car is a 1996 E300.

I'm confident (but not 100% certain) there's nothing really wrong with the SRS system. The light had been working normally until the bulb burned out a few weeks ago. I replaced the bulb, but now it's on constantly. I'm guessing I did something wrong when pulling the instrument cluster.

I tried the "disconnect battery for 10 minutes and hope it resets itself" approach, but that didn't work. I've also visually inspected the wiring under the passenger seat to see if there's any abrasion.

Thanks,

pjc
Arlington VA

jay_bob · #2 10-18-2016, 09:45 PM

You will either need the Mercedes HHT or Xentry to clear this. I have first hand experience with this, after my car got hit in the door, the body shop could not clear the air bag warning without taking it to the MB dealer.

The airbag controller's data pin only appears at the 38 pin connector under the hood in the W210 and requires the proprietary MB tool to reset it.

I just did this last week on my ML320, you have to do adaptation of the MAF sensors when replacing them, the dealer charged me $150 for one hour labor and a (free) cup of coffee and a donut...

ESchwab · #3 10-18-2016, 10:05 PM

My experience is different from that of Jay Bob. I have a '98 E300. My light came on when the front passenger seat sensor went bad. I replaced the sensor and went to Auto Zone clear the code so that the light would go off. They did it without charge, and it's been fine since then (a year or more ago).

jay_bob · #4 10-18-2016, 10:16 PM

Did the AutoZone plug into the OBDII under the dash or the 38 pin connector under the hood?

If they plugged into the OBDII and reset the air bag, that is not possible. On a 98 E300, only the power train CAN bus comes to the OBDII connector. The air bag data line comes to the 38 pin connector only, and there is no physical way to reset the air bag over the power train CAN bus in the gen 1 210.

Now if they did plug something into the 38 pin and were able to clear it I would love to know what they used, since everything I have been told is that there is nothing on the open market that will talk on the 38 pin port down to the individual modules on the first gen 210. That would mean that there is a product out there to get into the individual systems on these cars.

The only options I was aware of are finding a HHT on eBay (rare as hens teeth and over $1000 when you do find one) or rolling the dice on Chinese Bootleg Xentry system.

ESchwab · #5 10-18-2016, 11:53 PM

Jay Bob, The Auto Zone person used the plug under the dash (near the driver's door). I don't know what instrument or tool was used.

jay_bob · #6 10-19-2016, 07:26 AM

I think the only plausible explanation is that the seat sensor fault is a non latching fault. I had the same problem with my seat sensor. Mine turned out to just be a broken wire at a flex point under the seat, so I got some 3 conductor fine stranded cable and rebuilt the harness between the sensor pad and the connector. When I started the car after that, the SRS light turned off on its own.

However the seat sensor fault remained stored in the system. When I got hit in the passenger doors last winter, they had to replace both doors, but neglected to disconnect the battery first. This set a latching fault in the SRS controller (for the door airbag) that could only be cleared by the dealer with Xentry. I got a copy of the before and after printouts from the dealer. There was a stored fault for seat sensor in the SRS module.

Removing the steering wheel will have the same effect (setting a latching fault), if the hub air bag is disconnected with the battery connected.

I went into WIS and pull up the wiring diagrams, and confirmed there is no connection between the under dash OBDII connector and the SRS module in the Gen 1 210. The OBDII only has an ISO 9141 single wire data connection to the engine IFI diesel engine control module (not CAN bus as I previously said). The SRS module has a single diagnostic lead that goes out to the 38 pin connector.

Therefore it is physically impossible for someone to plug in a reader into the OBDII port and reset a latching fault on the SRS module on a 96-99 W210.

TimFreeh · #7 10-19-2016, 08:18 AM

I can confirm the passenger seat sensor is a non-latching fault type of SRS error. My 99 E320 Wagon has a bad seat sensor that will trip the SRS warning light if someone over 200 lbs is in the passenger seat. Once the exit the seat of if they're replaced by a lighter passenger the light immediately goes out. I've read the code with an SDS machine and when the light is on the code for passenger seat sensor is present. The 36 pin interface is the only way I've been able to get in touch with the SRS system.

I'm 99% sure its just a broken/frayed wire but I haven't bothered to fix it.

I'm also pretty sure that the original poster has some sort of SRS problem and I'd bet its the front passenger seat sensor.

compu_85 · #8 10-19-2016, 08:39 AM

I'd also venture that the SRS fault might have been for the lamp itself.

-J

torsionbar · #9 10-19-2016, 11:54 AM

pjc - you have a PM.

pjc · #10 10-21-2016, 03:46 PM

Big thanks to torsionbar for his valiant effort the other night to diagnose my problem. Unfortunately, his scanner and my SRS system wouldn't shake hands, even through the 38-pin connector, so we couldn't pull the codes.

And many thanks to all the other members for their helpful suggestions.

I checked under the pax seat again and noticed the absence of a yellow connector (see pix). So I think we can rule out a faulty seat sensor, as this car apparently doesn't have one.

Trip to the local indie scheduled for Monday.

pjc