Hi, I have posted before about this issue but things have moved on so it is a little different now. 2012 Skoda Octavia 2.0 Tdi Engine Code CFHC.
I appear to have rectified other faults that showed up originally with the and partly with the .
Having 'chemically' cleaned out the with the JLM 2 stage process which did have the desired effect in that it removed ash and soot as expected. Checked and reset all the values, filled with Shell Diesel and threw in a bottle of Forte additive, just for good measure. Took the car out for a very long drive, around 1h30m for about 120 miles. As constant speed as possible, 4th gear, 60 mph at 2500rpm. No EML, No flashing Glow Plug Light and No Particulate Filter Light and no smoke of any kind from the exhaust.
Couple of days later, Diesel Particulate Filter Light comes on and if ticking over or low speeds around town smoke appears on pulling away. Ran a scan with which showed no other fault registered so not looking at or (currently) at any faulty sensors. Tried a 'Service Regeneration' after taking it for a run out to get up to temperature and that did the same as it always has, kicks in, revs increase but soot content increases. I therefore took it out to the 'fast' road near where I live with the intention doing a regeneration when driving. However, firstly, when I pulled to set it up the car was running at fast tick over, around 1000 rpm, so I looked at the figures on the screen and the soot content was reducing so it was obviously attempting some form of regeneration. It got to around 15g and stopped reducing so tried to set up the driving regeneration but could not get that set up because the process was not as set out. To start with, Coding-II - 11 was 'greyed out and could not access it which was ok because i have the later engine. Entered the security code and then into Adaptation - 10, selected the Regeneration while driving, the values were both shown as 0 so entered the 'new value' 1 but came up with a screen asking yes or no to either using the value, using a default value or a value supplied? I tried using 1 & 2 as obviously I have no values available but it would not "Do It" and if I went back the Meas. Blocks 08 was greyed out so could not get into that.
So, I took it up the road and after around 15 miles the EML light came on and the Glow Plug Light came on and it went into limp mode. Pulled off, checked the fault code, P2458 Regeneration Not Completed in Time.
The one thing I have found is the exhaust temperature readings appear to be a bit on the low side?
Address 01: Engine (03L 906 018 C)
13:14:24
IDE00433 Particle filter: oil ash volume 0.00 l
IDE00434 Particle filter: soot mass calculated 11.48 g
IDE00435 Particle filter: soot mass measured 26.00 g
IDE02229 Exh.gas temp.sen 1 287.5 °C
IDE02233 Exh.gas temp.sen 2 -0.0 °C
IDE02234 Exh.gas temp.sen 3 133.6 °C
IDE02236 Exh.gas temp.sen 4 137.3 °C
I am wondering if when trying to regenerate it is injecting more diesel in for combustion but because the exhaust sensors are reading low it is not burning correctly and hence creating excess soot or the not being able to regenerate correctly? You can see the soot has climbed from around the 15g it had got down to up to 26g.
