CorAegean

Hi,

I have a 2009 SL550. Home Link is dead as a door nail. Indicator light never flashes when I try to push and hold buttons 1/3. Tried several times, with key in various positions, engine both on and off. I'm thinking there is a wiring issue.

Can anybody tell me (or have images, video, etc.) how to access the wiring inside? Wedge loose small cover behind the mirror base? Pull mirror at base to release spring load? If that part is correct, then how to check the wiring harness for power?

Thanks for any info.
Reid C

pjw1967

If my feeble memory serves me correctly, holding buttons 1 and 3 together is supposed to wipe out all existing codes. After that, have you tried to program an opener? If you press any button individually, do you get any kind of light, i.e. steady, slow flash, fast flash, or are they dead as well?

CorAegean

No, no light at all no matter what button(s) I push and hold, or push & release, etc.

pjw1967

If the fuses look ok (F38?), then you may have to wait for someone who has had this problem before on your model.

pjw1967

Since we're still without other comments, how did the buttons work prior to failure. i.e. did they work without any power? My '13 Durango buttons work with the car shut off, but the wifey's '14 ML only work with the ignition on.

On the bottom of my aftermarket Homelink mirror there is a set screw that holds it to the bracket that is glued to the window. You undo the screw and lift the mirror up and off the bracket. The wiring is direct into the mirror, i.e. no plug. You tuck it up under the front of the headliner. For a factory install there may be a plug. If your buttons worked with the ign off, you might be able to use a circuit tester to see if any of the wires are "hot". Ground the tester and just put the probe in each socket of the plug leading to the battery. If anyone of them is hot, then maybe the mirror buttons are worn out.

alb0711

Homelink was working fine, then yesterday it suddenly stopped. No lights. I haven't checked the fuses yet, Wondering if the OP figured out the cause of his homelink issue?


Allen

Heatwave

Did you ever get your Home Link problem sorted?

If so, what was the problem and what was the solution?

We go to school on one another here. I hope your Home Link works perfectly now.

alb0711

I am not the original poster, but have the same issue. I have an intermittent restraint system malfunction that causes the SRS light to come one. When the SRS light is on, homelink doesn't work. Like OP, not lights or anything. What I discovered though is when the SRS light isn't on and my car doesn't think it has a restraint malfunction then Homelink works fine. I'm going to take it to the dealer Monday, we'll see what they find and I'll post their resolution.

latemodel21

Interesting observation about the relationship between the SRS light and homelink function.

Relative to the SRS light coming on ... It is something that can be troubleshot at home. Having a star tester (or any code reader that reads mercedes specific codes) is handy of course as it will pinpoint the issue. However, if you don't have one, you can try re-seating the connectors on your seats as a marginal (higher resistance then spec) connection can cause an SRS light that resets on it own. Airbag faults on significant bags (steering wheel bag for example) wont reset on their own, but seat airbag faults often will reset on their own. Not saying this is your issue, but it is not uncommon for the SRS computer to read a squib (airbag charge) as questionable due to a marginal (increased resistance) connection. I have seen this multiple times on the R230.

If you do this, it is best to have the key OUT of the ignition when re-seating the connectors.

Cheers,
Chris

alb0711

Thanks Chris!


I'm new to this car and have a lot to learn. I did just get an icarsoft i980 OBDI tool that has the ability to reset the airbag faults. Per your advice I reseated the "easy" connectors under both seats. I'm getting a fault 9002 in the airbag system. The message says "control module n2/7 (restraint systems control unit) (circuit 15R): No voltage when voltage present at circuit 15"


Does this help narrow down the potential need to reseat a connector? I'm wondering if 15R is telling me the issue is in the "right seat" or somewhere else altogether? If I can narrow it down to one seat or the other, I'll pull the seat so I can get in there and reseat al the connectors.


Thanks for your help!
Allen

latemodel21

Circuit 15r is one of your circuits that is hot when the key is on. So this is telling you that one of your supply voltage to the SRS module is not present which is probably the same Supply voltage your Homelink. I'm on the road at the moment but when I get a chance later I look at a schematic which may indicate where you should be looking.

latemodel21

I could not find the year of your SL550 (life would be easier if folks would include model year in their info : ) ... I looked up R230 up to 2008 ... but 2009 and later R230s appear to be the same.

I printed out the power schematic showing the power coming into the SRS controller and marked circuit 15 and 15r (with a red box). I also marked their respective fuses (both in left front fuse box).

I also printed a picture of the fuse box showing f12, the fuse for 15r (to SRS).


oddly, it looks like the 15r for the homelink may be created in the N70 (over head control panel) using the CAN signal as opposed to being sourced from the ignition switch (I was thinking they did that so that it can be "prioritized" OUT in the event of a low consumer battery ... but that would be silly as it would leave you trapped in or out of your garage ...).

hope that helps,
Chris

alb0711

Thanks again Chris. My sl550 is a 2009 - will make sure I call it out in future posts. I checked the fuse, it is fine. I'll reseat more seat connections this weekend. Worst case I've got an appointment with the dealer Monday morning. I'll share whatever they find and try to get an explanation between the relationship between SRS errors and Home Link.

latemodel21

If you list your model year in your info (that appears below your screen name on the left side of every post you make), then it will always be there.


I think that your code rules out a seat connection issue, so I would not focus on that. Instead, you should re-seat fuse F12 and the power connector to the SRS module.

I would also see what else if anything is semi/non-functional in your overhead control panel (map lights, rain sensor, etc) as this may tell you more about your homelink issue.

Cheers,
Chris

alb0711

Took my car to the dealer, it had a restraint system error. The dealer replaced the right and left SIM(sp?). And once they were replaced they tell me they could see an issue with the EIS system. That was also replaced. 10 days later I've got my SL back. Home Link works fine and still had the programming intact.


It appears from my very newbie view that an issue with the SIM or EIS somehow caused home link to stop working.


Very odd!


Thanks for the help - love this forum!


Allen

latemodel21

Glad that you got it sorted and appreciate you updating the thread
Odd problems often are resolved by replacing a bad SAM (signal acquisition module).


Cheers,
Chris

Heatwave

My "odd problems" were resolved by replacing the EIS.

I'm glad you got it all sorted. Enjoy your car.