Newbie, educate me on Regens

Racin4ds

Member
Joined
Feb 15, 2020
Location
Ocala FL
TDI
2014 Passat SE
Hi Guys,

Been lurking for a bit and trying to learn as this is my first ever TDi, been wanting one for ages but were just never affordable. I own a diesel truck and have been working on Fords for ages, so I'm not a diesel dummy but I don't know jack about DPF, Regens, or none of the emissions BS as my trucks are all deleted. This car was a CPO so I have warranty in effect so I'll leave this one along for awhile...

Any way, how does one know when these things are running the regen cycle? I've heard it was bad to interrupt them and you should always try to let it complete before turning off?
 

VeeDubFamily

Well-known member
Joined
Mar 18, 2015
Location
Temescal Valley, CA
TDI
2013 NMS Passat TDI SEL
This is true, it’s thought to be best to leave them running or drive for a little while longer until the regen cycle is complete.

As far as telling when it’s occurring, you’ll notice that your at idle rpm’s are higher (1100-1200) and you’ll smell the diesel fumes being burnt off (if for instance in a garage).

The only real way to tell when it will precisely occur next (that I’m aware of) is with the use of a Polar FIS. This shows you soot values in the DPF and miles since the last regen. Using these two values one can see easily when it is going to occur again.

However regen frequency is based on driving habits and patterns. The more distance driving you do, the more predictable they will be and the farther apart. The more city driving that’s done will cause it to occur more infrequently and more often. I’ve seen intervals at over 400 miles and ones at about 250.

Here’s where you can purchase a Polar FIS and learn more about the capabilities. The values that I’m speaking of are seen in the factory dash display (MFD). The Polar device adds additional screens.

https://kermatdi.com/i-852-polar-fis-advanced-dashboard-display.html

Good luck


Sent from my iPhone using Tapatalk
 

DivineChaos

Veteran Member
Joined
Jul 27, 2019
Location
gets cold here
TDI
mk6 jetta sportwagen tdi
note that vag dpf will not work with all motors. although it is probably cheapest option. couples with an elm Bluetooth dongle. but its a cpo, so if anything were to break, its under warranty. Just make sure to always keep your last fuel receipt and the proper oil in it.
 

Scooby24

Well-known member
Joined
Jan 13, 2020
Location
Olathe, KS
TDI
2014 Passat TDI SEL
note that vag dpf will not work with all motors. although it is probably cheapest option. couples with an elm Bluetooth dongle. but its a cpo, so if anything were to break, its under warranty. Just make sure to always keep your last fuel receipt and the proper oil in it.
Good point. the CKRA for OP's car wasn't listed, but it works great on mine.

I paid for the pro version to show all the different sensors...it's a great monitoring tool and helpful to know exactly how long that regen takes (20 minutes!)
 

Racin4ds

Member
Joined
Feb 15, 2020
Location
Ocala FL
TDI
2014 Passat SE
Good point. the CKRA for OP's car wasn't listed, but it works great on mine.
I paid for the pro version to show all the different sensors...it's a great monitoring tool and helpful to know exactly how long that regen takes (20 minutes!)

I noticed that when looking at their page just a few minutes ago, will it work with my 2013 CKRA? I have a ELM327 module already, but don't own anything android so I'll have to pick something up.
 

Scooby24

Well-known member
Joined
Jan 13, 2020
Location
Olathe, KS
TDI
2014 Passat TDI SEL
I noticed that when looking at their page just a few minutes ago, will it work with my 2013 CKRA? I have a ELM327 module already, but don't own anything android so I'll have to pick something up.
I can't say for certain but it does for my 2014 so I would assume so.

Definitely helps you anticipate when to expect a regen and plan accordingly for that 20 minutes or so it takes to complete.

It's quite noticeable how much of a difference in throttle response there is too after you let it fully complete.
 

Racin4ds

Member
Joined
Feb 15, 2020
Location
Ocala FL
TDI
2014 Passat SE
Gentlemen, I figured I'd share something pretty neat with the group since you've all been so much help. I had an app on my phone (iPhone) that I've used for a long time with my ELM327 OBD adapter called "Car Scanner ELM". I think it was free but offers a paid version with a few more features as well.
Anyway, I decided to hook it up yesterday and wow!!! I can monitor and read All of the EGT sensors, and it even has a DPF Regen flag that tells me when it is either completing a passive or active regen! Fully tested yesterday and I watched my first regen cycle complete on my ride home, EGT's went up to around 1100-1200*
It also allows me to even monitor the level of AdBlue in the tank!

I would show you guys a pic of the app but being so new, I guess I'm not allowed to yet...
 

BroncoAZ

Veteran Member
Joined
Apr 25, 2009
Location
Flagstaff, AZ
TDI
2015 Touareg Lux, 2015 Passat 6MT, 2009 Jetta (long gone), 2011 Touareg (bought back 02/18)
Mine likes to regen on short trips. I tried waiting it out at first, but now I don’t worry about it as I would have to wait for it numerous times per week. My weekly commute to Phoenix is 135 miles each way, plenty of time to regen there, but I’m amazed how often it will start a regen at the end up my trip between refueling and my house. For now it’s all under warranty, when it isn’t there is a low likelihood that I’ll still own the car.
 

Funguy

Veteran Member
Joined
Jan 18, 2005
Location
Front Range of Colorado
TDI
2015 Golf Sportwagen dsg and 2015 Passat 6 M/T
My Scan Gauge monitors the temperature of the DPF. Anything over about 700 is a regen and the temps will continue to climb until it gets close to 1,500 F.

With the manual transmission the center dash display will call for a lower gear during around town driving. For example I would normally be in 6th at 47 mph and the display will ask me to shift down to 5th. That is the way I most often notice that a regen is going on but of course at highway speed that won't work since 6th gear is called for.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Gentlemen, I figured I'd share something pretty neat with the group since you've all been so much help. I had an app on my phone (iPhone) that I've used for a long time with my ELM327 OBD adapter called "Car Scanner ELM". I think it was free but offers a paid version with a few more features as well.
Anyway, I decided to hook it up yesterday and wow!!! I can monitor and read All of the EGT sensors, and it even has a DPF Regen flag that tells me when it is either completing a passive or active regen! Fully tested yesterday and I watched my first regen cycle complete on my ride home, EGT's went up to around 1100-1200*
It also allows me to even monitor the level of AdBlue in the tank!
I would show you guys a pic of the app but being so new, I guess I'm not allowed to yet...
What dongle are you using? I thought iphones only used wifi ODBII dongles.
 
Top