mazo89
New member
Thanks guys, I ordered it and will replace this weekend. I will let you know 
Technical P2454 / DPF differential pressure sensor issues
- Thread starter lycopersicum
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Technical
P2454 / DPF differential pressure sensor issues
mazo89
New member
@theoneandonly, @lycopersicum I'm starting to wonder if it's a sensor fault. While driving to Edinburgh on faster roads to collect the new (cheap) sensor, the check engine light went out. The error is still in MES, but I also ran a test in MES comparing Pressure Sensor (mbar) vs Engine speed (rpm) and it looks like the sensor follows the RPMs. Please see the attachment. My guess is that I might have an exhaust leak or maybe a break in the sensor wiring. I disconnected the sensor plug and sprayed it with some electrical contact cleaner.
What do you think? I also have the new sensor with me, so I'm a little bit less concerned about driving the 2000km back home.
What do you think? I also have the new sensor with me, so I'm a little bit less concerned about driving the 2000km back home.
lycopersicum
Member
They are listed as intermittent faults, right? (Guessing from the Polish word
)On the graph, the sensor looks healthy, the pressure seems okay too (though to check this, you'd need to record under load).
Does the fault recur quickly when you clear it? A recording where the fault appears would be useful.
mazo89
New member
Yes, all are intermittent. Sorry for polishThey are listed as intermittent faults, right? (Guessing from the Polish word
On the graph, the sensor looks healthy, the pressure seems okay too (though to check this, you'd need to record under load).
Does the fault recur quickly when you clear it? A recording where the fault appears would be useful.
First time after clearing, it returned immediately. Then after forced burning DPF out it didn't show up for 200-300km. And then each time after clearing it kicked in after few miles after starting the engine. Now I don't know since I was driving today for 100KM without check engine light and just plugged in the MES and instantly wrote the post. Do you suggest driving with connected MES and testing (mbar vs rpm) & recording live?
lycopersicum
Member
"Signal invalid" means the sensor readout was below 500 mV or above 4500 mV.
Above 4500 mV is very likely to be an electrical fault (sensor disconnected / failed open circuit): if that was real, that would be more than 1 bar of back pressure. The engine would barely be able to pull anything.
Below 500 mV could be an electrical fault like a short to ground. It can also correspond to a negative pressure which can happen if the upstream sensor pipe is disconnected or leaking causing the upstream pressure to appear less than downstream.
As the other error indicates a low pressure condition, that tilts the balance towards one of the last two conditions.
In my opinion the symptoms are compatible with a dying sensor which still works sometimes. When my sensor failed the first time, the fault was also intermittent in the beginning.
Yes, a recording of the sensor around the time of the fault should be informative, and a recording while driving would give a better idea of the DPF health.
Above 4500 mV is very likely to be an electrical fault (sensor disconnected / failed open circuit): if that was real, that would be more than 1 bar of back pressure. The engine would barely be able to pull anything.
Below 500 mV could be an electrical fault like a short to ground. It can also correspond to a negative pressure which can happen if the upstream sensor pipe is disconnected or leaking causing the upstream pressure to appear less than downstream.
As the other error indicates a low pressure condition, that tilts the balance towards one of the last two conditions.
In my opinion the symptoms are compatible with a dying sensor which still works sometimes. When my sensor failed the first time, the fault was also intermittent in the beginning.
Yes, a recording of the sensor around the time of the fault should be informative, and a recording while driving would give a better idea of the DPF health.
mazo89
New member
I managed to come back home on original sensor. Needed to clear the error twice, so that the DPF regeneration kicked in. I have changed the sensor at home to DELPHI and so far so good (no check engine). The sensor signal follows the RPM on the chart, so it looks like the original one. Thank you very much for your help!
