C250 CDI W204 DPF/Limp Mode

[classiccarzone]

I have just sorted this problem on a 204. Replaced the diff sensor and the code kept coming back and the soot content still reading high and increasing.
My back pressure was well within the limits; differential pressure was excellent but soot content and fill was reading high.
When you go into the icarsoft regen section it will say that it is not able to regen and direct you to a section where it does an automated examination and comes back with the real results-in my case 2.8% fill and .6g soot.
It will then allow you to do a forced driving regen.
I chose to put it on a Snap on diagnostic which still showed a problem with the diff sensor. I told it to renew the DPF and everything went back to normal.

Just fitting a new differential sensor will not cure the problem unless you do either of the above.

 

[OneForTheRoad]

I have just sorted this problem on a 204. Replaced the diff sensor and the code kept coming back and the soot content still reading high and increasing.
My back pressure was well within the limits; differential pressure was excellent but soot content and fill was reading high.
When you go into the icarsoft regen section it will say that it is not able to regen and direct you to a section where it does an automated examination and comes back with the real results-in my case 2.8% fill and .6g soot.
It will then allow you to do a forced driving regen.
I chose to put it on a Snap on diagnostic which still showed a problem with the diff sensor. I told it to renew the DPF and everything went back to normal.

Just fitting a new differential sensor will not cure the problem unless you do either of the above.

Post 3 . Your reply is exactly what I did 3 years ago. It cured my problems also.

 

[pcthrillrider]

i just changed my dpf sensor today and maf sensor used icarsoft says it cant regen as 400% full didnt help me

 

[OneForTheRoad]

i just changed my dpf sensor today and maf sensor used icarsoft says it cant regen as 400% full didnt help me

Have you tried doing a forced regen. Icarsoft goes through a series of events which eventually cleared my errors . You need to blow down the 2 pipes also to see if they're blocked .

 

[pcthrillrider]

Have you tried doing a forced regen. Icarsoft goes through a series of events which eventually cleared my errors . You need to blow down the 2 pipes also to see if they're blocked .

i done it 3 times now just makes it worse was 200% now 400% i blew down both pipes one was a little bit harder but could blow down it

 

[OneForTheRoad]

i done it 3 times now just makes it worse was 200% now 400% i blew down both pipes one was a little bit harder but could blow down it

I just kept on trying , I did also drive 30 miles at 2500 rpm , pulled into a parking area ,resetting error codes. Each time . It eventually caved in .

 

[pcthrillrider]

I just kept on trying , I did also drive 30 miles at 2500 rpm , pulled into a parking area ,resetting error codes. Each time . It eventually caved in .

no point in driving miles cos if the engine light is on or errors stored it wont regen but thx for the replys

 

[classiccarzone]

i done it 3 times now just makes it worse was 200% now 400% i blew down both pipes one was a little bit harder but could blow down it

If you are getting a 400% fill reading it is very very likely that your Differential Pressure Sensor is defective, and or the pipes are also blocked. A defective B19/11 sensor can also cause problems.

 

[OneForTheRoad]

no point in driving miles cos if the engine light is on or errors stored it wont regen but thx for the replys

I know , that's why I kept pulling in, resetting everything ,then carried on driving some more , what's 30 miles .

 

[classiccarzone]

no point in driving miles cos if the engine light is on or errors stored it wont regen but thx for the replys

Again a 400% fill is a false flag due to a failing Diff pressure sensor. With that changed go into the Icarsoft regen programme.
It will tell you it cannot do the regen as the DPF is too full.
It will then guide you to doing a test on the DPF. When selected it will do a count down, then it will increase the revs to 1500, eliminate the fault code and then it will tell you the correct fills of the DPF.
Did you go through that process?

 

[pcthrillrider]

Again a 400% fill is a false flag due to a failing Diff pressure sensor. With that changed go into the Icarsoft regen programme.
It will tell you it cannot do the regen as the DPF is too full.
It will then guide you to doing a test on the DPF. When selected it will do a count down, then it will increase the revs to 1500, eliminate the fault code and then it will tell you the correct fills of the DPF.
Did you go through that process?

it turned out to be the small pressure hose was blocked! i unblocked it clearded the codes there was 2 maf sensor p0101 p2463 that code has cleared fill level now 51% but it's still in limp mode ahhhh do i have to do a regen to get it out of limp mode? or is the maf code now causing limp mode?

 

[classiccarzone]

It needs to teach in the new Differential Pressure Switch. Supposed to complete teach in by keeping revs up for 15 minutes. I have not tried that, I have told it that a new DPF was fitted. I used Snap On for that. (Icarsoft was showing that my DPF was at 0.06 % full, so my fill level was a false flag)
Alternatively, the Icarsoft will go into the forced regen programme. It will say that it cannot regen. It will then bring you to a programme where it starts checking the true level of the dpf, It will then reset the codes, show you the correct levels and then allow a forced regen.

If your B28/8 DPS is showing 0.01 or .02. or .04 bar at tick over and your B60 Exhaust back pressure sensor is showing between 0.945 and 1.545 bar at tick over you do not have a blocked DPF.
If it is blocked and you cannot do a regen it may be wise to spray a DPF cleaner down the bigger of the two Differential Pressure switch tubes and leave it overnight.
Start it up in the morning and a steady rev will clear it out, then retry a regen.
It may be probable that the P0101 reading was because you either started the car without re-connecting the wiring plug for the MAF after doing the DPS switch