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MBWorld, I come to you needing help... major issues after LED install attempt.
MBWorld, I come to you with my head hung and tail between my legs. After a successful weekend of ABC accumulator installs and my new to me SL55 being free of all warnings, I decided to spend my Tuesday evening doing something I've done in probably a dozen of my older cars - converting the interior lighting to LED. This, as it would turn out, was a bad idea. I noticed immediate that the dome lights weren't working, but got a few of the other interior lights working and figured I'd circle back to those. This morning I noticed that my keyless go also wasn't working. On the way home I decided to pick up some halogen bulbs and just get things back to how they were. I installed the halogen bulbs, then disconnected the accessory battery to let everything have a nice reset. This would also turn out to be a bad idea.
Now I still have non-functioning dome lights, no keyless start, no locking/unlocking the car from the fob, and worst of all - the car says the top is "in operation" when stationary and a red "hardtop not locked" message when moving. I have tried clearing all of the codes with my Foxwell unit to no avail.
The code that seems to be consistent is a B1057 on several control modules for a fault in the CAN communication control unit N70 (overhead control panel), so seemingly something happened with the overhead control panel when the dome lights were replaced. I'm good with mechanical work, but electrical gremlins terrify me. What should my next steps be?
Can you connect directly to the overhead control panel and read the codes specific to that module? If you can't or if it isn't found on a quick test, it has probably lost power. Check the fuse (I don't know offhand which one) and go from there. The roof closed switch is read by the OCP, so if it loses power or communication roof will show in operation. Same with the locking, that is also an OCP function. I'm not sure what function it has for keyless go, but it probably has some role in that problem as well.
Can you connect directly to the overhead control panel and read the codes specific to that module? If you can't or if it isn't found on a quick test, it has probably lost power. Check the fuse (I don't know offhand which one) and go from there. The roof closed switch is read by the OCP, so if it loses power or communication roof will show in operation. Same with the locking, that is also an OCP function. I'm not sure what function it has for keyless go, but it probably has some role in that problem as well.
Thanks for the reply, the roof closed switch information is very helpful. I checked all of the fuses behind the passenger seat and all checked out well, did not look at the engine bay panel yet.
2005 R 230 SL350 (M112 3.7). Sold the 1966 W113 230SL recently
Toasting a fuse by installing a led seems an unlikely route. The OCP is a ***** to remove, at least in my R230, so I could imagine a contact issue afterwards, there. And maybe someone can chime in if disconnecting the acc battery only is sufficient for a 'total reset'.
Yes led lights are definitely not a good idea. On my w211 e55, I changed out the headlight park lights with canbus bulbs, and they have now damaged 2 sam modules. They only receive 5.3 volts now.
Same thing with my ‘12 Silverado that I decided to replace the dome light with a led. Put it in, it didn’t work, neither did all of the dash lights. Maybe I put it in wrong, but it took me an hour to find the fuse I had popped.
Decided to install led headlights in the c55. Great they turn on, but after a minute or so they start turning on and off. Need a resistor that turns the excess wattage into heat. not risking the Sam damage on this one
Update to this - the 7.5 amp overhead control panel fuse (#38 in the passenger side of the engine bay) was blown. Replaced the fuse and things seem to be functioning as normal.
I never celebrate total victory on these cars, but looks promising that it was just the fuse. Safe to say I will be living out the rest of my ownership of this car basking in the orange halogen glow.
Satisfying result. Fuses first - always fuses - when diagnosing faults. Probably you just shorted a hot when doing the upgrade. That's what they're for.
Purely a personal choice, but I like the old analogue glow of incandescent bulbs. Seems they're totally obsolete now though.
03-22-2023, 10:48 PM
MBWorld, I come to you needing help... major issues after LED install attempt.
