Peugeot Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
170 Posts
Discussion Starter #1
Got PP returning P1429 "Permanent fault. Differential exhaust pressure signal. Coherence of the differential pressure when stopped"

I have read on here this is most likely to be a fault with the differential pressure sensor, is that the case? Should I just go ahead and replace the sensor or would I be just guessing that is the cause? Can I check it in any way?

The car is a 52 Plate HDI 110, is this sensor located under the battery tray?

The "PEF Inlet/Outlet pressure difference" reading was 168 mbars, if that helps at all?

Thanks.
 

·
Registered
Joined
·
170 Posts
Discussion Starter #2
Just been out and checked the live values in the PEF parameters section of the engine ECU.

"difference in pressure between particulate emission filter input/output" reads:

  • 117mb without the engine started
  • rises steadily to 850mb after the engine is started and idling
  • doesn't go any higher or even fluctuate, even at 4000+rpm
Seems like the sensor has had it? Or could it be a blocked pipe?
 

·
Registered
Joined
·
648 Posts
I believe 117mbar is a failsafe reading. Start by checking the tubing for blockage, quick puff of compressed air should sort a blockage. If no blockage then swap the sensor. Yes the sensor should be under the battery tray.
 

·
Registered
Joined
·
170 Posts
Discussion Starter #4
I've got the old one off and the new one on, the design of the replacement sensor seems quite different.

Is it correct that the pipe that went to the front of the old one goes on the right of the new one? Back pipe to the left?

Also, the clips on the end of the hoses, how are you supposed to put them back on? Tried with plyers but couldn't quite manage to get it, any technique or tool advice would be appreciated. Was planning on just replacing them with jubilee clips but I can't seem to find any small enough.
 

·
Registered
Joined
·
170 Posts
Discussion Starter #5 (Edited)
Got them on... Used a pair of wire cutters to get the job done, bit fiddly but not too bad in the end.

Everything is back and on and the original fault code has cleared and not returned. Got one that came back after clearing:

P0100: Open circuit or short circuit to earth. Flow too low.

Think this is a longer standing fault code with my vehicle, pretty sure I have tried changing the Mass Airflow Sensor before and it didn't rectify it, I have a spare so I will try swapping them later and see whether it helps. Doesn't seem to be putting the engine management light on anyway, which is what I need in the short term to get it through its MOT.

Could this fault code be anything to do with the EGR valve? I am pretty sure I have issues with mine as when I had the MAF sensor unplugged the performance was very much increased as to when it was plugged in (it was at that point I swapped the MAF and it didn't help).
 
1 - 5 of 5 Posts
Top