2003 C320 - SRS light came on along with 1 malfunction and "take it to the shop" message on the dash. Scanned the car with the OBD reader and there are no codes stored.

Reading through previous threads on the topic it seems that most people recommend taking the car to the dealer since they have the computer that can read the codes correctly. There are several things that can be wrong and most likely it's one of the sensors that is bad, but only the dealer can tell for sure.

Is there anything else that we can do to troubleshoot prior to taking to the dealer to rule out something that can cause the SRS light to come on? For example, I unplugged each wire under the passenger seat one by one and cleaned the contacts with the electronic contact cleaner spray. Reconnected and drove the car for a couple of days but the light is still on. Anything else that one can try first?

 

I think the light has to be reset and not go off when the issue is fixed on its own.

 

Matt you are dead on, I tripped mine when I was doing the COMAND retrofit, but the guy that did my version coding reset it for me. Once it comes on you have to plug the car up to get it reset.

 

I tripped mine while doing an alternator exchange, seems that when the alternator is disconnected as well as the battery it throws an error code for the SRS (I even had a battery keeper running so that I would not lose power across the board). I tried everything to get it cleared to no avail.

$85 later and about 7 minutes for the indy to clear it, I was on my way. I wished that they really worked for the $85 but it was the easiest money that they made

 

Nothing was disconnected, the light came on all by itself. I found a couple of threads that said a faulty seat sensor can be the problem. Actually, most of the time it is the wire that goes to the seat sensor that is the problem and it can be repaired for free. I am going to take the seat out and check for continuity on the wire. If it is fine, then I will pay to get the codes scanned to figure out exactly what the problem is and go from there.

Here is the DIY thread for the seat sensor and the description of the problem: http://www.benzworld.org/forums/w210...placement.html

 

The SRS light will not go away on its own. You need a computer to reset it. If you didn't disconnect anything, then most likely something really did fail. I'd assume MB would put a ton of $ into making sure that their safety systems do not give false alarms.

 

Reading the thread I linked to before, it looks like IF the problem is the faulty passenger seat sensor/wiring, the light goes away without having to use the dealer computer to reset the light. That's why I think I will try to check the seat sensor wiring first, as it is a free and should not take that long. BTW, I tried unhooking the battery and waiting about 10 minutes, but the light stayed on, which was expected of course.

 

BTW, I'm having the same problem... just haven't had time to check... if you review my threads, you'll see that error message is also strange... not the normal error message everyone seems to get.

 

Trying spray some WD40 on the seat belt buckle (I guess that the SRS warning with only the driver in the seat), spray WD40 (or electrical lubricant), it may help (before you hit the dealer). I remember way back (may be 12-14 years), my C280 suddenly "SRS warning" appear on my way home from work, I am only one in the car, when I got home, with some WD40 spray to the seat belt buckle take care of it (never happen again until I sold the car). Good luck !

 

I tripped mine when I was doing the COMAND retrofit

 

Took the passenger seat out of the car and checked the continuity on the seat sensor wire. All 3 wires showed continuity without issues. Next step is to scan the code - either pay the dealer $130 or buy Carsoft 7.4 for less than that and hope that it works to scan the codes myself. If anyone has experience with Carsoft please let me know. I have an OBD II reader which connects to my laptop via a USB wire and then plugs into the OBD port. Like I said, it does not troubleshoot the SRS codes and i read that I need Carsoft 7.4 for this.

 

Take into account that Carsoft 7.4 correctly works only with real COM port's hardware, not with USB/COM converters.

 

I have an old laptop which has the right port, at least I think it's the right one.

 

Sorry if I missed it, but where you located? ...I've often seen others posting about drives over & scanning with other forum members. I'd gladly watch you use my equipment (at your risk) in my driveway, assuming you're near Syracuse, NY.

 

Thank you for the offer but I am in VA. I purchased the carsoft tool and will post back after I read the codes.

 

Vert if it does not work out I am in VA don't know where you are but would help out if needed.

 

Hello Everyone,
I made the silly mistake of starting my SL600 while sitting in the passenger seat. If you've not done this before, don't. Unfortunately, you will create a condition in which the car thinks that the driver seat sensor is faulty. I should have known better, I started my S500 with my knee in the passenger seat after opening all of the doors to treat the leather - Same thing happened then.

 

OK, I got the Carsoft 7.4 and erased the SRS code so the light is off and the malfunction message is no longer displayed on the instrument panel. Will drive around and see if it comes back...

Does anyone know where to get the user manual for Carsoft 7.4? It has a ton of abbreviations and functions and a user manual would be great to try to figure out some of the functions.

 

I recently had a similar problem with my C230, but the horn wasn't working, either. Because you haven't mentioned it, I imagine your horn is working fine? Still, I would check the horn/airbag clockspring. Sometimes, the ribbon cable inside will double-back & "fail". I had to buy a couple extra tools to do the job, along with a new clockspring, but it wasn't a difficult fix. Ebay is the way for so many things, so long as research is performed beforehand.

Also, mine threw no codes that I could read via my Bullydog or OBDII code reader, so even if the horn is working, it's still a possible cause because the horn portion of the ribbon cable inside the clockspring may still be intact. Let me know if you have any questions. I hope this helps!

- Matt

 

Horn is working fine. It's been 2 days of driving after I reset the SRS light with the Carsoft and it's not back yet. Still looking for a Carsoft user manual.

 

Excellent, I'm so glad for that! I hope the issue is totally resolved!

 

Hey Guys,
After a week of the SRS Light, I found my dash clear of the light after some 20-30 starts. Remember, I tripped mine while starting the engine from the passenger seat. It made a brief appearance only once since and now I'm on day 4 or 5 without the light. Yes, it still comes on at startup as part of the bulb check but apparently, the car is smart enough to clear the matter up itself if it finds that the fault no longer exists.
Has this happened to any of you?

 

Well, the SRS light and the instrument panel message are back after a couple of days of driving. I scanned it with Carsoft and got the message attached about the airbag. Could someone advise on the next steps? There are some suggestions in the message itself, but this is airbag we are talking about so I don't want to mess anything up. I am assuming this is the on behind the driver side door panel under the window?

B1035 - Ignition circuit front left sidebag: > Ohm (open circuit).

 

Found a Technical Bulletin based on the B1035 code and I guess this is the next step:

From http://www.benzworld.org/forums/w209...ssistance.html
and http://www.justanswer.com/mercedes/1...-door-srs.html

SRS - Warning Lamp ON/DTC's B1035/B1037/B103B/B1039
All Model Years
SRS Indicator Lamp On

If you receive customer reports in the above model vehicles that the SRS light is illuminated and diagnostic fault code(s) B1035, B1037, B1038 and/or B1039 are stored in the SRS ECU, the resistance in R12/11, R12/12, R12/20 or R12/21 ignition circuits for the sidebag squibs may be too high. This high resistance is caused by either of the following:

^ The left front door separation point connector X35/1,
^ The right front door separation point connector X35/2,
^ The left rear door separation point connector X35/3
^ The right rear door separation point connector X35/4.

To resolve, remove connectors from the wires for sidebags in the left and right front footwells and the left and right rear entryways and connect wires directly. Please follow the below procedure to repair.
Note: Always perform procedure on all 4 connectors.

1. Remove ignition key.

2. Remove A-pillar paneling in front foot well and door sill molding. Remove left front floor covering per WIS document AR68.20-P-2050P and right front floor covering per WIS document AR68.20-P-2070P.

3. Remove left and right rear door sill molding.

4. Expose wiring harness. Figure 1 shows connector for front doors X35/1 (left front door separation point) and X35/2 (right front door separation point). Wiring for rear door connectors X35/3 (left rear door separation point) and X35/4 (right rear door separation point) are similar. Wiring diagram of airbag control module with integrated E-call system can be found in WEB ETM document 91.60-U-2101FA.

5. Remove connectors and connect wires directly with solder connectors.

(A). Cut line approx. 10 mm in front of and behind connector.

(B). Remove about 20 mm of fabric tape on the control unit side.

(C). Strip about 15 mm of insulation from the wire.

(D). Slide solder connector onto wires.

(E). Twist both wire ends together, observing the wire color assignment.

(F). Position solder connector in the middle and shrink it on (solder) using a heat gun.

Utilize wiring harness repair set 220 589 02 99 00 and heat gun part no. 458-HL1802E via the MBUSA Standard Service Equipment Program.
(G). Inspect solder connection.

(H). Tape up both ends of the wires.

6. Delete fault memory with STAR DIAGNOSIS.

7. Install in the reverse order.

 

Are you going to attempt this...

I wouldn't if I were you, take it somewhere. Lest you blow your face off with one of the door bags.