DPF Regen - Install in-cabin indicator light

[MrGreedy]

Hi,

In my rubbish Insignia (soon to go) I've installed a 12v LED wired directly into the driver's heated wing mirror positive and negative wires.

The LED is neatly hidden behind the tweeter speaker grill in the front corner of the door, and lights up blue whenever the heated wing mirror are on. It could easily be positioned anywhere in the door by extending the wires.

The key is that when doing a DPF Regen, the ECU turns on the rear screen and mirrors to put additional load through the alternator and therefore engine, in a bid to increase engine temp. When it does this for a Regen, the LED lights up, but the button on the centre control panel to turn on the demisting is not depressed or lit!

Does anyone know if something similar happens on the w212 E350 Mercs?
I really would like an indicator so I can make sure I keep driving if it's doing a regen so I don't turn the car off and get a load of diesel dumped into the sump and all the associated damage that might do.

 

[MrGreedy]

In this thread, sixth post down, someone suggest the heated rear screen turns on during DPF regen:
Dpf explained

They have a 2011 350 CDI W221, so probably a very similar system.

If I can get a icarsoft diagnostic, would I be able to observe heated mirror or rear screen activation 'live' during a DPF regen?
I'd imagine they are probably on the same circuit.

 

[MrGreedy]

In fact, using my VIN and doing a parts search for the rear view mirror reveals A2128102621 for the driver's side mirror.
There is no mention of heat on the description. How do I know if this even has heating of the mirror?

 

[Mikesmith29]

Phone your local dealer service / parts dept they should be able to tell you.

 

[Petrol Pete]

Pop the glass out (easy enough , as any thief knows) and see if it has two wire connected to the back of it and you can actually see the heater element through the black plastic holder stuck on the back of the glass.I can't imagine that they are not heated on an E350. But with MB ...anything is possible.

 

[Mikesmith29]

The other option is to put the rear screen heater on and see if the mirror glass gets warm.

 

[skippyjasper]

In this thread, sixth post down, someone suggest the heated rear screen turns on during DPF regen:
Dpf explained

They have a 2011 350 CDI W221, so probably a very similar system.

If I can get a icarsoft diagnostic, would I be able to observe heated mirror or rear screen activation 'live' during a DPF regen?
I'd imagine they are probably on the same circuit.

Interesting read.


Sent from my iPad using Tapatalk

 

[Petrol Pete]

How does this 'extra load' work on vehicles without heated anything...van's for instance ? I know some (Ford) have an heated windscreen but surely two heated wing mirrors must be a tiny load in comparison

 

[Mr Filipov]

@MrGreedy best indication for you will be the gear change points and revs at idle.

The car normally idles at 600, but while doing a regen that will sit at 800.

The gear change points move closer to the 2k rev mark.

Exhaust note will be a bit louder as well and car will feel less responsive on the throttle.

The one point I will add is that you have to know your car to notice all of the above items. For majority of people if asked they will respond with I had no clue.

 

[MrGreedy]

How does this 'extra load' work on vehicles without heated anything...van's for instance ? I know some (Ford) have an heated windscreen but surely two heated wing mirrors must be a tiny load in comparison

I've no idea. It's heated rear screen as well, but wiring into the wing mirror is easier and more convenient to position an LED within easy view of driver.

 

[m80]

If you consider that most engines are churning out 100Hp happily, to my mind you want to load it with an extra 30Hp from what ever it is loaded at to make a worth while difference so that it heats up faster,
and it won't enter regen until the engine is up to approx 60 degrees anyway.

1Hp is approx 750watts (746 to split hairs), divided by 14volts that equates to a load of 53amps.
I don't see where you are going to find that additional load so as to load up with even a couple of extra Hp. The engine isn't going to feel it.

As for knowing when it is in regen mode. Install Torque onto a smart device. Buy a £4 OBD BT transmitter. Torque can monitor exhaust temperatures at the 2 important places and will demonstrate very well when you're in regen. Try it you would be surprised how fast, and how much, the temperatures rise. You will also see the DPF temp overtake the Cat temp.

 

[whitenemesis]

Most MB models heat the door mirrors automatically at temps below ~12degC, no driver intervention required.

 

[MrGreedy]

Just to be clear, I'm not personally looking to load up anything extra; I'm just repeating what I've read including other people's observations that for many vehicles, the heated screen and mirrors activate during DPF Regen. I don't know why manufacturers have actually chosen to do this.

I'm trying to find a way to install a permanent and discreet solution to easily identify when a DPF regen is taking place.

The wing mirror works on other cars, but if Mercs activate wing mirrors on any temp below 12 degrees (thanks whitenemesis), then this won't be consistent enough for use as a DPF indicator.

 

[m80]

I haven't read the link.
But I can't understand why any manufacturer would associate any heaters with the DPF.

 

[MrGreedy]

As for knowing when it is in regen mode. Install Torque onto a smart device. Buy a £4 OBD BT transmitter. Torque can monitor exhaust temperatures at the 2 important places and will demonstrate very well when you're in regen. Try it you would be surprised how fast, and how much, the temperatures rise. You will also see the DPF temp overtake the Cat temp.

I've already got this exact set up with Torque Pro. But it's not convenient in my opinion as it requires setting up Torque for every journey, and means I can't use my phone as easily for things like podcast, Waze, incoming calls.
A 'hidden' LED on the other hand would be great, but it seems like there's a lot of unnecessary sentiment against me seeking this solution and poo pooing what/why/technical merits of trying to achieve this. I find it really useful to know for certain when DPF regen is taking place.

 

[MrGreedy]

I haven't read the link.
But I can't understand why any manufacturer would associate any heaters with the DPF.

Given the illustrative calcs kindly put up by m80, I don't understand it either, but some cars do activate these systems when doing a DPF regen, and it would appear that the w221 is one of them. I can confirm Vauxhalls do it too.

 

[m80]

I wish you all success with your endeavour.

 

[Mikesmith29]

Most MB models heat the door mirrors automatically at temps below ~12degC, no driver intervention required.

My 2017 c300h requires the heated rear screen to be switched for the heated mirrors to work.

 

[whitenemesis]

My 2017 c300h requires the heated rear screen to be switched for the heated mirrors to work.

A retrograde step IMHO. I miss my door mirrors automatically clearing moisture. Never really noticed it before but the Merc always had clear mirrors even in just damp weather.
My RC300h needs the rear screen on to clear the mirrors as well. That said it's the first car I've owned that actually does clear the rear screen and really quickly to!

 

[rf065]

My 2017 c300h requires the heated rear screen to be switched for the heated mirrors to work.

I bet it doesn't.