DPF Regen - Install in-cabin indicator light

[piotreus]

Hi sorry for posting after such a long time but im wondering if the dpf regeneration runs in the same way in w204. I bought one a month ago and i,m looking for some dpf indicator solution. I found sth like that but cant find any info about this Grey electric relay function.

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

So at the and there are probablly two solution but i have no idea if it works in 204.
Thx in advance for your responding.

 

[MrGreedy]

Hi

This looks likes essentially the same method I used. It's the same car I have.
I chose not to fiddle around with the front of the SAM in case I damaged something, and they are super expensive to replace, hence using a push connector into the back of the heated screen positive wire.

I had no idea if this would work for my w212, but I guessed it probably would, which is why straight away I went to the effort of getting the seats out and installing the LED somewhere easily seen in the rear view mirror.

If you didn't want to risk the wasted effort for the W204, you can just run the wiring from the points I did, and poke the wire through with the LED so it gets to the cabin, and just tape up the dangling wire somewhere visible. Then drive around for 400-800 miles to check if the LED lights at some point when the rear heated screen is not switched on with the centre console button. If it does, then you could remove the appropriate trim and neatly install the wire. Unfortunately, the only way to check will be to test it.


If you have an iCarsoft scanner or similar, it will tell you when the last DPF regen was (in distance), so if it's a few hundred miles ago you know one is likely due. If a regen happened yesterday, maybe leave it 300 miles so you don't have the wire dangling around unnecessarily.

 

[piotreus]

Hi

This looks likes essentially the same method I used. It's the same car I have.
I chose not to fiddle around with the front of the SAM in case I damaged something, and they are super expensive to replace, hence using a push connector into the back of the heated screen positive wire.

I had no idea if this would work for my w212, but I guessed it probably would, which is why straight away I went to the effort of getting the seats out and installing the LED somewhere easily seen in the rear view mirror.

If you didn't want to risk the wasted effort for the W204, you can just run the wiring from the points I did, and poke the wire through with the LED so it gets to the cabin, and just tape up the dangling wire somewhere visible. Then drive around for 400-800 miles to check if the LED lights at some point when the rear heated screen is not switched on with the centre console button. If it does, then you could remove the appropriate trim and neatly install the wire. Unfortunately, the only way to check will be to test it.


If you have an iCarsoft scanner or similar, it will tell you when the last DPF regen was (in distance), so if it's a few hundred miles ago you know one is likely due. If a regen happened yesterday, maybe leave it 300 miles so you don't have the wire dangling around unnecessarily.

Thx a lot. I will do it just like you. Im very curious why there is such a few information about the regeneration process for mercedes instead of many info for other cars. Iis such difficult to find any important information. Hope it will works in w204 as well.
Thx again for your time.

 

[piotreus]

Thx a lot. I will do it just like you. Im very curious why there is such a few information about the regeneration process for mercedes instead of many info for other cars. Iis such difficult to find any important information. Hope it will works in w204 as well.
Thx again for your time.

Sorry for posting again. Itd like to ask you how long does a led light flash? Today i sam that mine turned mayby for a 30 sec? I dont know why? Mayby the dpf regeneration cant start?

 

[MrGreedy]

Don't worry about asking questions; that's what this forum is for. Feel free to ask away and if I have any ideas I will try and help.

If the DPF is regenerating, then it will take 5-10 minutes with the light on. Mine is not a flashing LED type, and just stays lit constantly for that time.

Also, if it is not doing a DPF regen, and just I activate the heated rear screen, then it is also lit for as long as the rear heated screen is lit (after all, it is just an indicator to say the rear heated screen is working properly, rather than a true DPF notification light).

If the light is only on for 30 seconds, say when you activate the heated rear screen from the centre console, then I'm going to guess something similar happens to when you activate heated seats but they have broken heating elements. The SAM or control module will try and supply power for a limited period (e.g. 30 or 60 seconds), and then if it doesn't detect other appropriate changes (a rise in temperature via the heated seat temperature probe in my suggested example), then it will cut the power an log a fault code.

When you say it is only 'flashing' for 30 seconds, do you mean the LED is a flashing type? Or that a 'constant' type LED is actually flashing?

And how is the LED activated? Is it via the centre console heated rear screen button?

If it's activating without the centre console button pressed, it could be an indication of the car trying to do a DPF regen, but then aborting due to other errors.

In all instances, I would get fault codes read using a good quality scanning tool.

 

[piotreus]

Don't worry about asking questions; that's what this forum is for. Feel free to ask away and if I have any ideas I will try and help.

If the DPF is regenerating, then it will take 5-10 minutes with the light on. Mine is not a flashing LED type, and just stays lit constantly for that time.

Also, if it is not doing a DPF regen, and just I activate the heated rear screen, then it is also lit for as long as the rear heated screen is lit (after all, it is just an indicator to say the rear heated screen is working properly, rather than a true DPF notification light).

If the light is only on for 30 seconds, say when you activate the heated rear screen from the centre console, then I'm going to guess something similar happens to when you activate heated seats but they have broken heating elements. The SAM or control module will try and supply power for a limited period (e.g. 30 or 60 seconds), and then if it doesn't detect other appropriate changes (a rise in temperature via the heated seat temperature probe in my suggested example), then it will cut the power an log a fault code.

When you say it is only 'flashing' for 30 seconds, do you mean the LED is a flashing type? Or that a 'constant' type LED is actually flashing?

And how is the LED activated? Is it via the centre console heated rear screen button?

If it's activating without the centre console button pressed, it could be an indication of the car trying to do a DPF regen, but then aborting due to other errors.

In all instances, I would get fault codes read using a good quality scanning tool.

 

[piotreus]

I used wrong word. It,s not flashing ty0e led. Its constant. I plug it in the rear SAM. It's probably wokrs in the same way as yours. Because when I push rear window heating button it turns on and if I turn off the rear window heating the led light turn off as well. So I thing it work properlly. So as I thought it could be the attempt off regenaration. I'm going to my mechanic to check front axel so I asked him to check the errors and check the date of last completed regeneration and the last ubandon one.
I will let you know or will ask about other ideas
Thx ones agains

 

[MrGreedy]

Don't worry about using the wrong word. No problem. Your English is much better than my Polish! by a long way!

Can I just check, if you leave the heated rear screen on for, say 2 or 3 minutes, does the screen stay on for the full time?

If it does, then it strongly points to DPF failing to initiate, and the checks you have said are exactly the correct ones to look for. Good luck.

 

[piotreus]

I will check it tomorrow but i think it will stay on for full time. But we will see.

 

[Justintyme]

Don't worry about using the wrong word. No problem. Your English is much better than my Polish! by a long way!

Can I just check, if you leave the heated rear screen on for, say 2 or 3 minutes, does the screen stay on for the full time?

If it does, then it strongly points to DPF failing to initiate, and the checks you have said are exactly the correct ones to look for. Good luck.

I am following this thread closely, as its something that I'm interested in too..and can't figure out why there is not an inbuilt icon to tell you when a regen is taking place. But what I'm wondering is, why not take a connection directly of the actual cable supplying the heated rear screen to activate the LRD warning light? Or would that affect the canbus and cause a fault code to be generated?

 

[MrGreedy]

I am following this thread closely, as its something that I'm interested in too..and can't figure out why there is not an inbuilt icon to tell you when a regen is taking place. But what I'm wondering is, why not take a connection directly of the actual cable supplying the heated rear screen to activate the LRD warning light? Or would that affect the canbus and cause a fault code to be generated?

The black cable I recommend coming out of the rear SAM unit is the actual cable supplying the rear heated screen

 

[piotreus]

I am following this thread closely, as its something that I'm interested in too..and can't figure out why there is not an inbuilt icon to tell you when a regen is taking place. But what I'm wondering is, why not take a connection directly of the actual cable supplying the heated rear screen to activate the LRD warning light? Or would that affect the canbus and cause a fault code to be generated?

It doesnt affect any fault code. If you want to take a connection to rear window heating wire you need to plug it in the some place between rear sam and rear window because the electricity flows directly form fuse to relay and after that the fuse doepend on signal let the electricity flow to rear window.


I tried to make connection to the fuse wich protect rear window heating but the led light was still turn on.

So I chacge the collection to te frelay.

Hope,I help you in some way .

 

[Justintyme]

It doesnt affect any fault code. If you want to take a connection to rear window heating wire you need to plug it in the some place between rear sam and rear window because the electricity flows directly form fuse to relay and after that the fuse doepend on signal let the electricity flow to rear window.


I tried to make connection to the fuse wich protect rear window heating but the led light was still turn on.

So I chacge the collection to te frelay.

Hope,I help you in some way .

Yes you have helped me.....my idea was too good to be true !!! So you can only use the live wire to the screen as a trigger for a relay., Good, thats that explained.
Thanks.

 

[Justintyme]

The black cable I recommend coming out of the rear SAM unit is the actual cable supplying the rear heated screen

Ok. So connect a relay to this wire to use it as a trigger to supply power to your DPF warning LED.
Thanks MrGreedy.

 

[Ted]

@Justintyme, you shouldn’t need a relay for this as the amount of current taken is miniscule compared to the amount taken by the screen element.
If you do use a relay, make sure that you include a diode across the windings (cathode to positive) to prevent any voltage spikes when the relay is de-energised.
A 1N4001 will be fine, or the relay might have this built in.

 

[Justintyme]

@Justintyme, you shouldn’t need a relay for this as the amount of current taken is miniscule compared to the amount taken by the screen element.
If you do use a relay, make sure that you include a diode across the windings (cathode to positive) to prevent any voltage spikes when the relay is de-energised.
A 1N4001 will be fine, or the relay might have this built in.

Thanks Ted, I'll remember to do that, !!!

 

[piotreus]

Don't worry about using the wrong word. No problem. Your English is much better than my Polish! by a long way!

Can I just check, if you leave the heated rear screen on for, say 2 or 3 minutes, does the screen stay on for the full time?

If it does, then it strongly points to DPF failing to initiate, and the checks you have said are exactly the correct ones to look for. Good luck.

I checked the led light when the rear window heating button is on. It lighted all the time so it is probably the attempt of dpf regeneration. When I will know more I will share with you

 

[piotreus]

Hi guys I found the solution for the issue i mentioned before.The reason why led indicator turned on for a while was broken fuel temperature controller. I fixed it and now waiting for next procedure to check if everything is OK.

 

[merc64]

Hi will the dpf led mod work on the C250d 2017 from the relay I know where the rear heated screen relay is located ive been looking in to this and it a great idea if it works, is yours still working?

 

[MrGreedy]

Hi will the dpf led mod work on the C250d 2017 from the relay I know where the rear heated screen relay is located ive been looking in to this and it a great idea if it works, is yours still working?

Mine is still working. DPF Regen approximately every 400-600 miles. LED still illuminating, so all working as I hoped.