Year of Manufacture *: 03/2006 Engine Size and Code *: Z19DT ( Optional ) ECU Type: CR/EDC16C9 ( Optional ) Scanner Used: Modis / KTS ( Optional) Fault Codes: P1901
I read the codes for this customer a week before Easter and came up with P1901, MIL comes on after a few miles usually under heavy load (he wanted codes read only)
Modis description: Particulate Filter Pressure Sensor Hose line Malfunction
The customer had Googled this one all over Easter and concluded it needed a new pressure sensor, he tried to fit but could not get the two small rubber pipes off, so he brought it in yesterday for me to fit, which I did
It came back in this morning with the MIL on after about 10 miles going home, he now thinks it may require a forced re-gen or can I take the DFP off for him to clean out and for me to refit next day
I did check the archive and it did suggest cleaning out the DPF for this code (but not this model)
After speaking to Darren Cotton (just up the road from me.....thanks Darren ) he suggested I smoke tested the 2 pipes that go back to the DPF, which I did
Smoke coming from under the vehicle, underneath the plastic pipe had melted where it joins the metal pipe
Made up a new pipe (I believe a modified pipe is available)
The pressure sensor is located on the side of the fuel filter mounting, so you can smoke pipes from here
I wonder how many DPF have been replaced by workshops that dont have a smoke machine?, then back the next day with the same code
HTH Someone
Peter
PS: In all fairness the Modis did come up with the more definitive description, the Modis Troubleshooter suggested a software update and forced re-gen
It is with considering why the plastic pipe melted?
The metalic section of pipe is there to withstand the heat generated at the DPF & it is sufficiently long enough to protect the rubber/plastic section of hose that connects to the differential pressure sensor. hot gasses should not really travel that far up the metal pipe & I wonder if you might have a small leak nearer to the pressure sensor.
I had a 307 hdi with just this fault a while back. The hose was burned just like yours & I later found a tiny crack in the rubber hose at the sensor, that allowed a flow of hot gas to flow through the metal pipe and cause the damage.
These differential pressure sensors are blind, (like a blind bolt hole) & there should be no passage of gas through the pipework, only pressure variations.
A crap explanation but I hope it makes some sense!
on May 10, 2011, 2:41 pm
) he suggested I smoke tested the 2 pipes that go back to the DPF, which I did 
