No DPF Regen in rain

   #1  

grittysoup

Verified VCDS User
Verified
Joined
Dec 26, 2015
Messages
18
Reaction score
7
Location
UK
VCDS Serial number
C?ID=362815
I have a 2E 2008 VW crafter 88 Deisel, I have had the DPF warning light come on yesterday, a quick trip up the motorway for 20 minutes normally solves the issue, today however the van wa sent up the motorway, but it was raining ... the van has come back with a flashing Coil Light flashing and the Exhaust System fault light on, as well asthe DPF wanring light still on - tomorrow I will follow my own thread to see if this resolves the issue:
https://forums.ross-tech.com/index.php?threads/20227/

I understand a regen requires a very hot temp in the exhaust to burn off the soot, could the rain have kept the DPF too cool ? it was driven ni 4th with 2500 on the rev counter, which in previous dry conditions I observed in VCDS,. kept the DPF above 500 deg.

Any one have any thoughts on my rain theory ?
 
   #2  

dieseldub

Verified VCDS User
Verified
Joined
Nov 7, 2017
Messages
112
Reaction score
151
Location
Bay Area, CA
VCDS Serial number
C?ID=28764
Rain won't affect it. If there are faults stored for any of the various temp sensors, diff pressure sensors or any one of a number of other of things, it won't allow a DPF regen to initiate. And if this goes on too long unaddressed, the soot loading becomes too high to where it's no longer safe to perform a DPF regen on the vehicle and thus the computer will no longer attempt to regen...
 
   #4  

grittysoup

Verified VCDS User
Verified
Joined
Dec 26, 2015
Messages
18
Reaction score
7
Location
UK
VCDS Serial number
C?ID=362815
Ran a scan this morning on way to work, looked in block 70, DPF loading is at 50%.

Followed the instructions in this KB article:

(Coding II code entered was 20016 (not 21295 as per article)

The Particle Filter Carbon Mass started dropping straight away, once all was up to temp, and zip up motorway, dropped to zero and both DPF and Coil lights went out after few minutes, am left with engine waring light still, scan gives:
008194 Particle Filter Trap Bank 1
P2002-000 efficiency below threshold
- uintermittent

Can I reset all DTC's and see if it returns, presume it was/is connected with DPF needing the emergency regen.

I had a couple of auto-regens interupted last week, so guess thats why it needed the emergency regen ? does the Particle Filter Carbon Mass gets above a certain %, can the vehicle no longer do an Auto Regen on its own ?
 
  • Like
Reactions: Uwe
   #5  

Uwe

Benevolent Dictator
Staff member
Joined
Jan 29, 2014
Messages
31,154
Reaction score
22,184
Location
USA
VCDS Serial number
HC100001
the Particle Filter Carbon Mass gets above a certain %, can the vehicle no longer do an Auto Regen on its own ?
Yes, there comes a point where the ECU will refuse. If there's too much soot, once it starts burning, it can't stop and risks catching the whole vehicle on fire.

-Uwe-
 
   #6  

grittysoup

Verified VCDS User
Verified
Joined
Dec 26, 2015
Messages
18
Reaction score
7
Location
UK
VCDS Serial number
C?ID=362815
So the 'automatic' operation of the regen is disabled once a regen could become a danger, and one needs to force the Regen through the Emergency Regen procedure, I note your caveat that the vehicle could catch fire, this is third time I have needed to do this, are there any recorded instances of vehicles cathcing fire, and was any Particle Filter Carbon Mass recorded prior to ignition !

Do I understand correctly that the upper level of Mass is about 65/70% loading ??

The Engine warning light remained on for the rest of the day, following morning though it did not come on with the first start of the day. So all good.
 
Last edited:
   #7  

dieseldub

Verified VCDS User
Verified
Joined
Nov 7, 2017
Messages
112
Reaction score
151
Location
Bay Area, CA
VCDS Serial number
C?ID=28764
So the 'automatic' operation of the regen is disabled once a regen could become a danger, and one needs to force the Regen through the Emergency Regen procedure, I note your caveat that the vehicle could catch fire, this is third time I have needed to do this, are there any recorded instances of vehicles cathcing fire, and was any Particle Filter Carbon Mass recorded prior to ignition !

Do I understand correctly that the upper level of Mass is about 65/70% loading ??

The Engine warning light remained on for the rest of the day, following morning though it did not come on with the first start of the day. So all good.
If the soot loading is high enough, the computer won't allow a forced service regen either for safety reasons. At that point, it would have to be removed from the car and cleaned by other methods or outright replaced.
 
   #8  

MartinsX

Verified VCDS User
Verified
Joined
Sep 5, 2016
Messages
1,150
Reaction score
1,230
Location
Riga, Latvia
VCDS Serial number
C?ID=268515
Rain won't affect it.
Are you quite certain about that?

-Uwe-
I am. System is designed to work and do regenerations when needed in all seasons and weather conditions ;)
Of course if OP was driving in so extreme rain that all exhaust system was under water, it may be an exception :D:D:D
 
  • Like
Reactions: Uwe
   #9  

colinb

New Member
Joined
Jun 27, 2018
Messages
6
Reaction score
2
Location
Hornchurch, UK
Had a similar problem with virtual same conditions and readings on a snapon diog.
What was annoying was it would go away then come back,
Solution, dropped DPF and found bits braking away and getting caught against the botton sensor which stick out into the pipe a long way, it would fall away then another bit do the same thing. Replaced the DPF. Ok till this starts to happen again.
 
Top