Post-fix CJAA regen duration and frequency (high speed highway use)

sn0ri

Member
Joined
Nov 26, 2017
Location
Hadley MA
TDI
‘14 jsw tdi (black) formerly ‘05 jetta tdi sedan
Hi all! I recently bought a <80k mi 2014 sportwagon from a family member after getting a new job with a 120+mi round trip commute which made me a bit suspicious of some easily fixable but annoying electrical issues on my ‘05 BEW Jetta (which is now with said family member and is re-purchasable in a pinch…)

I love the wagon and it’s a highway *monster* compared to my mkiv, but I want to make sure I’m watching the emissions system correctly. I’ve put around 800 miles into the wagon so far after driving it home last week (essentially all fed. highway at 75mph+ — I’m not a conservative driver) and I’ve noticed 2 active regen cycles before today, but they’ve lasted a *while*: 25+ mi driving at state highway speeds on the first (not sure when it started, but that’s assuming the start is when I noticed), and 25 minutes on the second after getting where I was going (parked and let it idle after realizing it was in regen). Currently sitting at my house after a rare local drive (around town <15mi) and a regen has been running for 15 minutes after parking.

I’ve read through the existing CJAA threads, re: maintenance and longevity, but a lot of them date from before the “fix. Is this duration and frequency on regens expected? Or should I be concerned? I know they’re more frequent after the fix, but I haven’t seen clear advice on “when to worry” other than checking for soot at the tailpipe and making sure the regens are happening at all.

In anticipation of needing to be vigilant, I’m getting a VAG-Com cable to look at the emissions blocks etc. I know the obvious response is to ask for VAG-com numbers, and I don’t have them yet. Wanted to post and ask before then (partially because I haven’t found a great source for normal (post-“fix”) behavior after searching).

(before anyone asks — I’m in Massachusetts, so the emissions system needs to stay intact, even beyond the warrantee. That’s why I’m planning around emissions inspection and maintenance so carefully…)

Thanks as always :)
 
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DrGERTol

Veteran Member
Joined
Aug 27, 2020
Location
NW OH
TDI
2011 Golf Variant (JSW) 6MT
When you get your Ross-Tech cable, look at 01-Engine Measuring Blocks 240 (Last Regen) & 241 (DPF Soot Load). In particular 240/3 (mileage since last regen), 240/4 (elapsed time since last regen), 241/2 (calculated soot load), and 241/3 (measured soot load). More info in this VW Tech Tip: https://static.nhtsa.gov/odi/tsbs/2013/MC-10070753-3639.pdf
When to worry -- probably when emissions related DTCs (e.g., P2002, P0401) start appearing.
 

JELLOWSUBMARINE

Veteran Member
Joined
Mar 3, 2014
Location
yes
TDI
2011 Jetta Sportwagen, 6M, red/tan, navi, pano, 83 5m diesel pickup, 82 p/u trailer,.04 5.5 TDI Passat wagon (gone), 80,81,82 diesel p/u (gone), 80,82 sportruck (gone), 59 passthru bus (long gone), 79&87 westy (gone), 57 baja bug (long gone), 73 914
A regen every tank or so seems to be the general consensus as is my typical regen.

After the Kerma tune the active regen is the same frequency as the pre tune. Although there is a difference in the active regen duration (shorter). Post tune hits high temperature burn off for a couple miles (2-3 exits usually) if on the freeway. I've asked the Kerma reps on why the cleaner tune doesn't extend the active regen frequency with no real answer. Maybe the time/mileage perimeter has not been altered with the tune(?). My take on it is the actual soot load has been minimized creating a quick burn off.
 

ShelbyRazorback

Well-known member
Joined
Oct 31, 2018
Location
WI
TDI
2012 Golf TDI 6MT
I noticed regens happening twice a tank. I recently moved and work is just over 9 miles away. My regens seem to take almost the whole ride home ish....
 
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