Help please! - 2021 New GLA DPF regeneration problems/issues... reject the car?

alexanderfoti

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Most regens on most new mb's are carried out without the driver knowing. They usually only take 2-3 minutes if that. I would have thought 2 x 30 minute regens which still are not complete would indicate an issue. Probably with the DPF Differential pressure sensor. If the car Regens to much, it will eventually log a fault code for regen frequency too high.
 

bladecrazy

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totally agree there must be an issue to keep continuously doing regen after regen , that mileage should be sufficient to complete .
 

MangoOfQPR

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Here's something I may be able to help with!

Bear with me as this'll take some explanation!

A few years ago, I suffered a similar issue to the OP but with a Mondeo. I'd drive and it would go into limp mode and not go above 40mph. My mate, a car mechanic, suggested that to force a regeneration, I should get into the A14, near where I live, get up to 60 in 3rd, pop cruise control on and drive for about 10-15 mins. This would create the necessary heat to burn off the carbon deposits and regen the DPF.

Tried this a few times and although it seemed to work a couple of times, the issue kept coming back.

It took a Ford mechanic to check a second sensor to discover that that one was faulty. Changed the sensor and all was well.

If you have a dual carriageway, it may be worth a try or get a check to see if there's another sensor that's been missed.

Hope that makes sense!
 
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roryg

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GLA 2021 200d AMG Line Exec
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Most regens on most new mb's are carried out without the driver knowing. They usually only take 2-3 minutes if that. I would have thought 2 x 30 minute regens which still are not complete would indicate an issue. Probably with the DPF Differential pressure sensor. If the car Regens to much, it will eventually log a fault code for regen frequency too high.
Yes, this is what I would expect based on Mercedes own technical document saying it should take a "few" minutes.

However, the dealership are not accepting my request to reject the car because I believe the DPF regen process to be faulty, even though simple common sense indicates it must be faulty!

Even copied the managing director into my last rejection email but they still want to see the car again even though they already had it for two weeks and did nothing to resolve the issue because there were no error codes from the diagnostics.

MB unwilling to accept the obvious (to me at least) fact that there is a fault.

This started after the first regen attempt at 400 miles or so when the wife came in after the school run complaining of a bad burning smell.
I went out and it was very worrying,a really strong burning rubber smell that just felt wrong. This is a brand new car and this smell was like the car could ignite at any moment. It was that bad. Repeated, even worse smell and heat, a week later. I shouldn't have to put up with this on a brand new car.

The really worrying aspect is that the dealer doesn't even accept there is a problem. What can I do get a refund? Get MB UK involved?

Thanks for all your help, comments and suggestions, it's really appreciated.
 
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roryg

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GLA 2021 200d AMG Line Exec
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Most regens on most new mb's are carried out without the driver knowing. They usually only take 2-3 minutes if that. I would have thought 2 x 30 minute regens which still are not complete would indicate an issue. Probably with the DPF Differential pressure sensor. If the car Regens to much, it will eventually log a fault code for regen frequency too high.
Oops, forgot to ask...
what would be the symptoms of a faulty DPF Differential pressure sensor?
I've always suspected that the regen IS completing but the system isn't recognising it so keeps on pumping fuel to the exhaust system, effectively overheating it badly and wasting lots of fuel.
Could a faulty sensor be causing this?
 

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