[ditzy48]

Hi,

When night driving all lights behave normally for a while - then, from time to time, the main beam will dip of its own accord.

From that moment on it is not possible to get main beam via the column stalk. EVEN MORE strange is that it is not possible to turn the lights OFF.

Everything is just stuck. Stop the car, switch ignition off, switch on, and everything is back to normal. Just like a computer freeze.

2015 ForFour, 19000 miles.

Any ideas please ??

ditzy

 

[SubRosa]

The headlights cannot be turned off when in high beam mode, just flip them back to low then rotate.
SR

 

[ditzy48]

Perhaps I did not explain clearly. The lights ARE in dip - they go to that state by themselves- it is NOT possible to go to main beam, or switch them off - all controls are "frozen" until the ignition is turned off - THEN the lights can be used again and switched off, When switched back on they operate normally.

It does not matter that I cannot switch them OFF while driving, but not being able to get main beam is disconcerting to say the least when driving in dark areas.

 

[Miss Mercedes]

I've experienced this same thing with a 2016 fortwo pure that I had as a loaner. I stopped at a fuel station and found out I had no control of the lights. Stalk was in the full off position (high beams not on..I couldn't even turn them on or flash them during the glitch), but the lights were stuck on. Turn off the car, take out the key...and lights still stuck on. They only turned off after restarting the car and shutting it down again.

Computer glitch, maybe? My 2016 fortwo edition #1 doesn't do that at all.

 

[Yinzer]

It's a problem with the (unfortunately expensive) SAM. This is what we get when something as simple as turning a light on an off is relegated to a computer and software. The SAM is the flat box with all the fuses under the dashboard.

The most common things that cause a SAM to fail is water intrusion and use of higher wattage than specified headlights. But the SAM in my 2015 ForTwo ED failed (thankfully on warranty) for no apparent reason other than maybe it was not mounted correctly so it rattled when hitting bumps. My failed SAM caused the locks to randomly lock and re-lock every few minutes to seconds.

There are some aftermarket businesses that re-flash used salvaged SAM modules to a new state (called "virginizing"). The virginised (as you spell it across the pond) SAM then still needs to be programmed for each individual car and remote key with the MB STAR syatem that dealers and MB mechanic shops have. This is much cheaper than having a new SAM installed and programmed at a dealer. Still a few hundred dollars/pounds though.

The joys of the digital age....

 

[Woody14619]

To me, that sounds like a low 12v battery going on. I'd say to check your battery output, and/or try putting it on a trickle charger.

I saw a very similar behavior back in my 2008 smart about mid-life, where if I had high beams on, it would flicker them off to low a few times, and eventually get "stuck" in one mode or the other. If you're running with high beams often, it may not be recharging properly.

 

[Miss Mercedes]

Low battery shouldn't have been a factor in my case. It was a brand new 453 pure with less than 1k miles on it. :shrug: I think Yinzer may be onto something about the SAM. And if true, I don't want to think what's going to happen when the SAMs in affected 453s are 10+ years old.

 

[Smart Bob]

This symptom occurred on a friend's low mileage 453 ICE smart under warranty. The dealer ordered a new SAM. The SAM'S are a Renault component. Car has been out of service for a week waiting for parts.

 

[figgy]

I've experienced this same thing with a 2016 fortwo pure that I had as a loaner. I stopped at a fuel station and found out I had no control of the lights. Stalk was in the full off position (high beams not on..I couldn't even turn them on or flash them during the glitch), but the lights were stuck on. Turn off the car, take out the key...and lights still stuck on. They only turned off after restarting the car and shutting it down again.

Computer glitch, maybe? My 2016 fortwo edition #1 doesn't do that at all.

We have a wonderful low mileage 2016 Passion from a private seller and tonight we experienced EXACTLY what you guys are describing.

All was fine when we started (high beams went on and off from stalk, everything normal).

Then after driving for a few hours just on low beams the entire time, I wanted to flash my high beams and discovered that the high beams did not flash and did not turn on either.

Then I discovered that while driving I could not turn the lights on or off either (as reported).

When I got back home, the lights stayed on and the high beams did not go on or off when pulled or pushed on the stalk. The lights stayed on no matter what the setting INCLUDING of "Off" setting.

The I took keys out and put them back in and restarted the car, and it worked correctly.

This is exactly 100% what you guys report!

 

[twcom]

Almost every car I have had with intermittent light issues with no apparent cause has turned out to be bad ground related. But to get a shop to just check ground issues first rather than start chasing and swapping out things takes a lot of stern will but who wants to piss off a mechanic who is about to work on your baby. It is a much easier conversation at an automotive electrical repair shop.