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GLC 250d Malfunction! warning on LCD screen

17646 Views 16 Replies 10 Participants Last post by  Chris Jurgeit
Has anyone else with any GLC model had a Malfunction! warning (Picture outline of a car) up on their LCD screen i.e. behind steering wheel LCD?

I have a GLC 250d that is ~ 14 months old, & this warning has suddenly just started coming up over the last couple of months.

I've now had the car in for repair at 2 different MB dealerships for a total of 4 days in workshops & neither has been able to fix.

Ist dealership replaced the Air valve control box (apparently flown in from Singapore) for the Air Body suspension - made no difference. The 2nd dealer thought that there may have been a loose connector somewhere & stripped down car panels & checked all connectors that they could access & they thought they'd found a couple of loose ones. Again no difference.

The usual first thing that all repairers do these days is to upgrade software which was also done at first repairer.

Interestingly, I've noticed a flash up on the LCD screen of the rear seats (maybe seatbelt sensor) just prior to malfunction warning. I have mentioned this to reparers but they don't think it's related. The issue is now consistently coming up, although it can be random as to when it occurs. I just have to acknowledge it, hit OK & it goes away. I haven't noticed any loss of car function or performance.

Appreciate any feedback
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G'day Stacoq and welcome to the forum from Pommieland.

The outline of a saloon car in side profile does indeed indicate a malfunction has occurred with the Air Body Control system. If it is amber in colour rather than red, it is the notification of a non-critical fault. In my case the car's management computer was not happy with the release time being taken to depressurise the ABC. It was taking too long and because it had now fallen outside operating tolerances, the malfunction icon would appear. The light would not come on immediately after starting the car but would activate at random times ranging from 5 - 30 minutes. Once on, it would stay illuminated until the engine was switched off and then the whole procedure would start again. Like your experience, there was no discernible difference in the performance of the suspension and the warning could be cancelled until the next time by hitting OK. Hooked up to the Star Diagnostics machine at my Dealership, the fault code that was thrown up pointed to the air compressor unit. A replacement was ordered and fitted the following week. It took about 90 minutes and the malfunction has not appeared again in the 5 months since the compressor was swopped out. I'm so glad this problem appeared within the warranty period as I suspect the cost of a replacement pump would not come cheap.

Hope you get it sorted without too much aggro.
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If they can't fix your vehicle after three tries, I think you can enact the lemon law and get a new GLC. But hopefully it won't come to that and Toobad's fix works for you.
Thanks Sir Toobad from Pommieland :) - your outline was spot on, Thanks. It's exactly what I've been experiencing & as I suspected, I wasn't going to be the only GLC owner in the world experiencing this. Great to have this Global forum for the GLC. I've also have no doubt that we aren't the only GLC owners with ABC option that are having this issue & that MB engineers will be aware of the problem. Looks like there is an issue with either engine management programming or mechanical issue with de-pressurising valve sticking or both. Either way, it's something that MB needs to address. Interestingly, like you the 1st repairer had the same diagnostic fault code that pointed to the ACU. My ACU was also swapped out, but problem still persists, which may suggest programming is implicated as well. In fact, the amber coloured saloon with the malfunction warning came on as I drove off from the 1st repairer with my new ACU!! 2nd repairer confirmed that swapping out the ACU is the MB recommended action to take & given that this hasn't corrected the fault, loose electrical connections are next best troubleshooting action. Now that checking all of the potential electrical connections hasn't fixed problem, they want to escalate resolution with MB engineers. Surely, I haven't got a 2nd dud ACU. They claim they'll need car for at least 2 days. I have it booked in again for 17th October. Fingers crossed. I'll pass on your feedback to my repairer & I'll try to hold back on the aggro. Very frustrating given $$ spent on vehicle purchase & not what one expects from MB.

May have to take Karl's advice & invoke the Lemon law!!

Again thanks for your feedback.
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I have the exact same issue. The car is roughly 16 months old. Couldn't call the dealership today as its Saturday.
Hi SR-Ickenham - As suspected we are experiencing a common issue with the GLC250d that has the Airbody control (ABC). Hope you get quick resolution with your dealership. May be worth sharing this thread with them. I'll post outcome of my repairers fix after the 17th Oct. Good luck & welcome to the forum. Please post outcomes of your repairers diagnosis.
Update on my GLC250d ABC issue:

Didn't actually go to my dealer on the 17th October as scheduled, as my issue seems to have resolved itself after playing with the rise button on the console for a while. This appears to have done something to improve the release time from the ABC controller. All good for now ......hopefully stays this way.
Mine's started to do this everyday now for the last 4 days, after 5-10 mins driving. Once the messsage comes up, I can "ok it", but it remains in the message list on the service menu. It then seems to disappear the following day on switch on.

I also note that if I press the console button to raise the car, it comes up "lowering" and it stays there pretty much forever. No matter how often I press the button, it never goes to "raising". I'm pretty certain my car is at maximum height all the time and can not be lowered. Going over speed bumps that I drive over regularly definitely feels different. I'm booked in next week for a service and to get this looked at. Oh an ANOTHER 2 led door handle lamps to be replace (I think that 6 in 2 years).

Also a GLC250d, mines is just coming up to 2 years old with around 11K miles.
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Hi and welcome to the forum. Wonder if you're the same tangey who posts over on MB Club UK?
Hopefully a replacement compressor will restore normal service but it will probably need a return appointment for fitting as it is unlikely your Dealer will have one on the shelf. I couldn't detect any difference in the ride quality during the malfunction. Coincidentally I had to have a failed driver's door handle LED replaced so I asked to have it done at the time of the compressor swop. The diagnostics also threw up a fault code for the front passenger handle so, although it was still working, it was also replaced at the same time.
Hi and welcome to the forum. Wonder if you're the same tangey who posts over on MB Club UK?.
The one and same, I googled for the airmatic problem and it picked up this forum.

And now I'm wondering if I can get them to sort out the airbag recall at the same time, even though I haven't had notification yet. I'm guessing they don't get paid by mercedes until the formal notification has been sent out.
well, apparenly a sensor was gone in the compressor, and unbeleivably, they had a compressor in stock, so it's been replaced.

Car being delivered back tomorrow.
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GLC300 Malfunction!

I too had the Manfunction! warning come up on the LCD screen. My GLC300 4matic with air ride is almost 18 months old. Thankful the repair work is covered under warranty. I dropped the car off at the dealer the same day as the first warning happened as I had no idea what the warning was about.

The car has been in the dealer's shop for 5 days now. Each day they call an tell me to keep the loaner one more day the need an additional part.

Based on reading in this forum, I really hope they figure this out..... really don't like the CLA they gave me to drive and want the GLC back in working condition.
Hi - I had the same problem on my GLC 250d. Dealer replaced the air compressor under warranty - not only did this fix the issue but I realised that the air body control was probably never fully working from new. Not having had this suspension system before, I thought air body control was okay - but not good enough to consider it again. However, with the new air compressor, the ride is now sensational - better than it ever was.

As an aside the rear seat belt warning lights were also showing in my car - since new. However they went out after about 10 minutes.I just assumed this was a quirk of the car. However, once the amber warning light for the air suspension came on, the belt warning lights remained on as well (the dash warnings fluctuated between the air suspension and the seat belt warning).

Replacing the compressor seemed to also fix the seat belt warning.

My local MB dealer (Newcastle AU) was great - they needed my car for a few days but found me a replacement vehicle straight away. As above, the air suspension is now working properly and I have reassessed my view of its value - I will definitely opt for it next time around. Also very happy with MB's focus on getting my car fixed and back to me as quickly as possible.
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I too have had this problem with a 250D - It turned out that the problem was a faulty sensor but they replaced the compressor assembly before realising that it as only the sensor. Apparently they did it this way because the vehicle's diagnostics doesn't drill down to the ultimate culprit and since it was under warranty. they replaced the whole lot.
I dont have a warning but my 250d compressor seems to run very often?

I went to the shops 1/4 mile away and it came on 3 times.

Then when I was sitting in the driveway about to switch off it came on and I noticed the front of the car go up!?
Should I be worried???
I dont have a warning but my 250d compressor seems to run very often?

I went to the shops 1/4 mile away and it came on 3 times.

Then when I was sitting in the driveway about to switch off it came on and I noticed the front of the car go up!?
Should I be worried???
Interesting reading on the malfunction message. My GLC250d is 3 1/2 years old and now out of warranty. I had a fault with the ABC a couple of years ago and the car ‘dragged its bum’. The problem was rectified by dealer. Now I’ve had the malfunction message (only once) but following this I lost control of the drivability of the car. All functions of ABC worked, but the car held revs in all modes, eventually changing up at a higher road speed (I never saw more than 5th gear though). Flat throttle didn’t kick it down and I couldn’t use paddles or manual override. The car would step down through the gears as I came to a stop. I pulled over and had lunch. After about 90 minutes I started the car and it drove as normal - it kicked down, I could use the paddles, I could override the auto function etc. this sort of thing makes me nervous because it usually means large sums of money to repair. Any observations would be welcome.
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