Volvo DPF Pressure

[TruckDoctor]

(06-02-2019 )RHeller11 Wrote:  Yes! It originally started when I had a coolant leak. It was a hose going to cool the turbo. It was december/cold and I didnt want to tackle it myself since the turbo had to be removed. Since the Volvo dealership had the turbo off, they suggested they inspect the egr cooler since it was easy access. Well, of course it came back as leaking. Had them put in an egr cooler at that time. They put it all back together, flashed the ACM to the latest and sent me on my way with a healthy bill. A few days later my truck asks for a parked regen, It had never asked for one prior to this. I proceeded to do it. Within 200 miles, the soot level was over 100% again. ugh...brought it back and said what happened? they checked the pressure and said my DPF and DOC needed to be cleaned. I am like, OK, 350k on it, I will bite. Cleaned the DOC and bought a new DPF filter. Installed it all myself and no change, DPF soot level increases to 100% within 200 miles. I proceeded to change the inexpensive parts myself like the pressure sensor and temp sensors to hopefully find an issue. No go, didnt fix anything. Then I tested the EGR valve, it was stuck open. I figured my problem was solved. Replaced the EGR valve and was hopeful. Nope, still the same. I think I got a bad flash on the ACM since thats when all the issues appear to start. My next plan of attack is to try and get the ACM reflashed. It has been in and out of Volvo so many times in the last 6 months with them trying to figure it out. They do a forced regen and all the numbers are within spec. So with the messing around I have done cause Volvo is getting me no where. I checked the 3 temp wires and pressure sensor wires to the ACM, all were good. checked pressure sensor input voltage, 4.94 volts. check pressure sensor output voltage .615 volts. I have to assume that if my soot level was truly at 100+% my output voltage from the sensor would be significantly higher than .615 since the range is .5 to 5 volts. This is what is leading me to believe the ACM is not reading the sensor correctly. Thoughts?

Like I said. US10 trucks fill with quoted soot level 100% really fast. I don't have the knowledge to explain why, but like I said I've done a regen on a truck that says 13% when done and gone on a 30 mile roadtest and the soot is back up around 100%.... with that 200% threshold that I told you I wouldnt worry.... I think your chasing the "Soot Level" and not an actual soot loading issue. Trust the DPF Pressure being its low. Your most likely fine. If the soot load is an actual issue you'll start getting "Parked Regen" requests.