Active Headlamps Inoperative
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CLS400 4Matic EC Tuned
Active Headlamps Inoperative
Just got done installing the rear ambient lighting to 12 colours from 3 on both rear doors, I probably had the vehicle to the on position with the headlights on for about 20 minutes. 3 hours later, I go for a drive and the first message I get is "active headlamps inoperative". The low beams work fine, they do their dance at the start, the car is clean and the cameras are clean from the windshield. I flick the turn signal lever to the middle, then push it back to where it would be for adaptive high beam assist, same error, try it again, and it automatically keeps the high beams on now since the adaptive high beam assist is now inoperative. Weather is completely dry, nothing was wet. As I was driving, I turned the car off twice to see if it would go away and it still didn't. Any ideas?
Last edited by Idklol69; Mar 13, 2021 at 02:29 AM.
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CLS400 4Matic EC Tuned
Went into the car again, got the error. I turned it into the on position and manually turned the low beams on by turning the switch right, and kept the lever in the middle position so adaptive was on. Individually checked if each light was working properly and they were. Put it back to auto with the lever in the middle position, no error. Turned car off again, put it into the adaptive position pushed back, no error. Think all is good now but it's weird that this issue would arise because my adaptive high beams never go on since it's a North American vehicle..
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From: Ireland
GLC 300d 4matic
You say you were working in the car for some period prior to encountering this issue... is it possible that the windscreen got 'fogged' up with condensation on the inside during the period you were working?
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From: North Cali
2005 SL500, 2015 CLS400
My 2 cents - I was getting the inoperative message since I bought the car, the previous owner stated it was due humidity making its way to the electrical sensors / wiring. In reality ended up being a weak battery. I did replace both batteries though. Pretty easy to check battery condition at a shop but eliminates the possibility I went through
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CLS400 4Matic EC Tuned
Humidity is not an issue here and no fog as I looked and as it was 14 degrees C in the garage the whole time. Hopefully just a glitch in the system if it pops back up I will update this thread.
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CLS400 4Matic EC Tuned
Okay, spent about a few hours doing the ambient lighting on the dash/driver's door, did a lot of on cycles and even turned the car on during the process to make sure the new wiring was in sync with the rear ambient lighting, no errors all day. Just went for a night drive, got the error. Tried what worked last night and it didn't work. Cycled the car on/off 3x. Weird how it only happens after I work on the car, maybe the battery draining causes an issue, even though I haven't noticed issues with starting. Will see tomorrow..
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CLS400 4Matic EC Tuned
Afternoon drive today, same error on startup. I flick the lever into the middle and back into the adaptive position (which usually gives me another error indicating that adaptive is inoperative and if I were to pull it back to the middle and back to adaptive, the high beams stay switched on permanently), and I saw the A in the dashboard. Drove around, switched vehicle off and on while it was in the adaptive position no error..
Currently driving in heavy rain hopefully this glitch in the system goes away.
Currently driving in heavy rain hopefully this glitch in the system goes away.
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CLS400 4Matic EC Tuned
Will do, but that’s even if I can find my aux battery as it’s nowhere to be found. Ironically I drove in eco for about 20 minutes and the car turned off at a red light which I haven’t seen in a couple of months. Main battery shows 14.8V while started on the cluster.
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From: North Cali
2005 SL500, 2015 CLS400
I'm more concerned about if the battery can hold the charge, because mine was showing the same output, but the capacity was nearly half of what was supposed to be.
Also my aux one was in the trunk, next to the spare tire.
Also my aux one was in the trunk, next to the spare tire.
