Still trying to sort out my SRS/9 pin issue - PeachParts Mercedes-Benz Forum

sokoloff · #1 01-03-2008, 09:03 PM

See attached photo of the diagnostic port I've got and the thread I've got going about the "OBD1 code reader." That is the only diagnostic port I can find on my car. It is a non-California version, so it doesn't have the blink code reader diagnostic port I hoped it would. Is there some way I can read fault codes for the SRS system on this port? Does it also serve as a blink code reader on some of the terminals or is everything duty cycle?

My SRS light comes on about thirty seconds after I start the car and stays on for the duration of the trip. I want to find out which part(s) is bad before I start replacing things willy nilly.

Thanks for any advice.

mbdoc · #2 01-04-2008, 08:00 AM

I ASSume the car is a 1988 560SL? The pic you posted is for reading engine info, incl duty cycle. No SRS info there.

You need the 8 pin connector just inches in front of that connector. Pin # 6 is for analog SRS codes.

sokoloff · #3 01-04-2008, 10:42 AM

Excellent Doc - thank you so much. I knew if I was enough of a pest about this issue, that eventually I'd find a solution. I bet I searched that engine compartment a half a dozen times at least trying to find another diagnostic port. I centered my search mostly around the passenger side near the firewall, since I thought that's where I thought others said it would be located. Now that I've found it I've got a reason to go to Radio Shack today and buy the parts needed to build the analog blink LED scanner to find out what's really going on with my SRS system.

Yes, it was for the 560SL.

Thanks again!!!

sokoloff · #4 01-06-2008, 08:26 AM

Thanks to MBDOC and Deanyel I was not only able to find my missing diagnostic port, but I also built a code reader and I think I found the problem. Looks like a bad SRS control module.

sokoloff · #5 02-02-2008, 01:14 PM

After building a code reader and testing the SRS system, I get a #2 error code that according to the codes tells me that the control unit is bad. I want to verify with someone in the know before I commit to buying a new/used part. It is my belief that the control unit the error code is referring to is the sensor located behind the climate control unit in the dash. My original unit shows part #003 820 73 10. That part has been replaced by part #004 820 17 20 and then by part #000 820 68 26 according to the EPC. The EPC also shows a condenser (energy reserve) and a voltage transformer electrical unit that look like they are located somewhere behind the driver's door. I guess one could possibly call these control units too. There is an error code for voltage supply which I would guess may refer to a bad voltage transformer. I see no error code that would lead me to the condenser.

Can someone please verify for me that error code #2, control unit, refers to the part behind the climate control unit like I think it does? I don't want to throw money away at a part I don't really need.

stevebfl · #6 02-02-2008, 01:26 PM

Did you try and clear it? There are 2 codes for the controller on the tunnel. Number 10 will never clear. I don't recall ever getting number two, but I would try and clear it first.

sokoloff · #7 02-02-2008, 02:12 PM

Thanks for the reply Steve. Yes, I did try to clear it, but it came right back. I initially had code 2 for the control unit and code 3 for the steering wheel contact rings. I cleaned up the contact rings, cleared both of the codes and now I only get code #2.

Len