[DslGate]

I just went went through my 1st Regen today, but @diesel is correct, there appears to be a "pre-Regen" that lasts for about a minute where the MAP drops below 14 on the Scan Gauge ( at least mine did) before the actual Regen starts ( #1 on my Scan Gauge 2) . This could be the point at which the DPF is getting flooded with fuel and the the DPF is heating up because once the actual Regen starts ( #1 in the gauge) , the Soot Mass starts to drop pretty quickly.

Bump for for update to this thread: Since I @GlennGlenn get the frequent regens at less than 60 miles between regens since firmware reflash at dealer two months ago, I've become somewhat "quite" familiar with regens, seeing two-three a day. Dealer says this is normal and to be expected.

Just before a regen, you will see the Map go below / less than 14 on the SC2. This is the period when you do not want to turn off your CTD. It's not in pre-regen long, perhaps two minutes or less, but it is setting the system up for the actual regen which is indicated on the SC2 as #1. If you interrupt the pre-regen , you'll get a #3 on the sc2 and this is not good. Interrupting the #1 is fine as the car will just start regen mode once it gets to temp. You do not want to unterript the preregen that is just before the SC2 goes to #1.

 

[DslGate]

@diesel , it appears that from my DIC and the Scan Gauge 2 that during the pre-regen period , two things are happening: 1. The DPF is at temp or getting to temp in anticipation of a regen and 2. The fuel system is dumping fuel into dpf for ignition and burn off of soot. This is illustrated by the MAP going below 14 for at least in my case about 1-2 minutes and The DIC showing less than 99 mpg when you're OFF the throttle ( illustrating that there is fuel being dumped into the DPF and thus your car is using fuel / dumping fuel into dpf while off the throttle). Interestingly, I also observed that mine will not do any regen or go into regen if the rpms are lower than 1500. I even tried to see if regen would occur in neutral and it would not.

Regen or pre-regen will not occur IF the vehicle is not up to normal operating temp, which for me is just below or just /before the half-way point on the engine temp gauge. If I start the car and soot is at 22 Soot Mass , the pre-regen and regen will not start until the car temp is near the 1/2 hash mark on the engine temp gauge.