moretech

 

Code B1010: N2/7 (restraint systems control unit): Undervoltage at terminal 15R/15
This was the only code shown by his scanner. If any member knows where the 15R terminal receives its signal from (SAM?) I might find my problem and solve it. I do not find any other electrical malfunctions in my displays or elsewhere. Thanks for any ideas!

moretech

 

Check your voltage. You might have a simple battery voltage issue.
Too bad you weren't close by. I have a Star SDS. You should do a total systems/ error check. It verifies if V are low or isolates individual fails

Try using a multimeter for now

 

Thanks Hary, batt is at 12 volts and is an AGM only 5 months old. Also when the old one went bad and I got "consumers offline" almost daily it never set SRS codes. I do wonder a bit about the ignition switch, but it seems it throws a lot of stuff at you when it is busted. Is there a fuse I might check?

moretech

 

Found this. IDK if it is relevant to your situation but maybe

http://www.benzworld.org/forums/w210...10-n2-7-a.html

 

The SRS controller is powered directly from the ignition switch when the switch is in position 1 ("15R"), and in position 2 it gains an additional feed ("15") from the switch through a fuse. I presume the B1010 fault results when the 15R voltage is significantly lower than the 15 voltage. If this is the case, then I would suspect you have a faulty ignition switch, though it could also be a poor connection between the switch and the left-side fuse box.

You can check the voltage on circuit 15R by measuring voltage on any of the following fuses in the left-side fuse box: 11, 14, 16, 18, 21, 22.

 

Hey there Bob Terry you may have hit on something!! I measured the voltage on the "spare" fuse and the rear batt and they are identical. But my very new AGM batt seems to show only 11.5 v, starter batt 12v. I drove it some and the trunk battery shows 12v now. Tried the SRS light again but still is on. So I am thinking I will not yet see my MB indy. I do not have any other malfunctions but for sure with the switch on position 1 voltages are identical going battery to fuse box connector. However, I remember when my old trunk battery was saying consumers offline in the mornings my SRS light did work normally. Your thoughts are appreciated, understanding the circuit is imperative to a solution. One last thought, from this information, could the SRS module be shot and that is what is causing code B1010? I too am wondering about a wiring harness malfunction.

moretech

 

Yes, that is a possibility.

You might check the integrity of the wiring. You might presume the connections at the ignition switch and SRS controller are fine and not bother with them. At the fuse box the 15R power connection from the ignition switch is made with a 2-wire connector labeled "C1" somewhere on the underside of the box. The 15R connection at the box going to the SRS controller is a 2-wire connector labeled "I2", though there is only a single wire.

If those connections are fine, I might do a simple experiment to learn something about the B1010 fault. How long must the voltage go low to set the fault? For the answer, with the ignition switch in position 2 I would remove the C1 connector and observe how much time elapses before the fault light is set. The length of time will dictate what strategy you use to monitor and detect a low-voltage event. I have several ideas on how you might do detection, and I may mention them in a later post.

 

Thanks for all the help!!. I have one last thought. If I pull the SRS module from the console and try to check the connector plug for voltage (ignition on position 1) would more than one opening show positive in a good harness? I'm guessing not, but any idea which hole in the plug in connector is the 15R feed or its color code for 2003 year car.? I'll let you rest after this one!!

moretech

 

The connector has 84 sockets (picture). Circuit 15R is wired to #29, circuit 15 to #1, and chassis ground to #84.

 

Thanks a ton load!!

moretech

 

Problem finally solved, problem was the seat belt pretensioners. Ended up replacing both at my MB indy. He reset my SRS light but was sure it would come back, which it did a few days later. He said really both should be replaced which I did when it came on again, No problems since driving it the last week.

moretech