Fault code advice P244A7A

[Grahamc250]

Hi all,
I couldn’t see a related thread and thought I’d ask for some advice from people in the know.
I have just put a diagnostic on the car and have come up with the following fault code and diagnosis
P244A7A - pressure differential in dpf cylinder bank 1 is too low.
Leakage of defective seal detected.

Other than taken it to a mechanic which isn’t possible being a Sunday and me being impatient what exactly is the way forward with this . Far from a mechanic but understand short journeys are not great however it does have more short than long. Could this be a go for a long drive and see what’s what situation or get to mechanic and limit driving ?? Any advice welcomed thanks in advance

 

[Continental]

Firstly - am not in the know… but does your diagnostic tool have live data? If so I’d probably be looking at what the related dpf pressure sensor shows for the model of car (with engine running) and what figures show with a press of the throttle… then compare to what they should be - if it doesn’t show a reading then perhaps that sensor has died/needs replacing. Some diagnostic tools can do a forced regeneration of the dpf I believe that may also be worth investigation perhaps - but hopefully someone in the know will be along to offer better advice.

 

[Grahamc250]

Thanks for your reply … gods honest truth I have the gear no idea but we all start somewhere haha it’s a reasonable bit of kit topdon artidiag500. Literally used it once so far to diagnose wheel speed sensor failure so has already paid for itself!!! Having just being able to fiddle with the diagnostic I have it does actually have a live data… the values of the dpf pressure sensor says 0.0 bar even with engine on I’m guessing this should have a reading?

 

[Continental]

That would be my guess too buddy - think the sensor has given up perhaps? What model car?

 

[Grahamc250]

would make sense have no reading at all if there was a leak it would show some value at a guess. Just looking into how hard it is to change . Already spent 3.5k on it in the last few months ud think it would give me a break now haha it’s a manual w204 c250. One more sensor to add to the bill and hopefully nothing more than this

 

[Continental]

Quick Google looks to be a £50 quid ish part and haven’t watched it all but think the following link shows how to replace it.

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[Grahamc250]

Just watched that one myself doesn’t look to sad a job. Mines a 2012 so Not exact model but a rough idea what to expect…. Thanks for your help and input appreciate it

 

[Continental]

Just watched that one myself doesn’t look to sad a job. Mines a 2012 so Not exact model but a rough idea what to expect…. Thanks for your help and input appreciate it

Welcome - hope that cures it - yeah doesn’t too much of a pain to replace that one.

 

[Grahamc250]

Update for anyone that can give input.. I cleared the fault code and took it for a short drive (drop lad off at school) and thought while the fault is clear check to see if there is any reading on the pressure. As there wasn’t anything yesterday when the fault was flagged
So now it showed a reading so I’m now thinking if it’s taking a reading it can’t be a broken sensor ?
engine light never came up on the short trip so abit unsure now do I carry on and just see if it comes up again?

 

[Continental]

Update for anyone that can give input.. I cleared the fault code and took it for a short drive (drop lad off at school) and thought while the fault is clear check to see if there is any reading on the pressure. As there wasn’t anything yesterday when the fault was flagged
So now it showed a reading so I’m now thinking if it’s taking a reading it can’t be a broken sensor ?
engine light never came up on the short trip so abit unsure now do I carry on and just see if it comes up again?

Post up the reading values from the sensor perhaps? Tbh… if it has cleared, not reappeared, and some live reading showing from the sensor now I would probably give the car a decent run at slightly higher than normal revs, or as some say Italian tune up might even stick in some of that dpf cleaner off the shelf stuff and a some shell premium diesel.

 

[Skd884]

would make sense have no reading at all if there was a leak it would show some value at a guess. Just looking into how hard it is to change . Already spent 3.5k on it in the last few months ud think it would give me a break now haha it’s a manual w204 c250. One more sensor to add to the bill and hopefully nothing more than this

£3.5k OUCH

Scrap it and purchase a late c180 petrol 204.

 

[Grahamc250]

Gearbox failed engine mounts needed doing clutch and fuel mass needed doing. sensor list went on cars been mapped only done 76k ain’t no scrapping it now great advice tho

 

[Grahamc250]

Post up the reading values from the sensor perhaps? Tbh… if it has cleared, not reappeared, and some live reading showing from the sensor now I would probably give the car a decent run at slightly higher than normal revs, or as some say Italian tune up might even stick in some of that dpf cleaner off the shelf stuff and a some shell premium diesel.

I did take photos but having hassle posting the pics but at idle it’s 0 bar when I took it round the block literally didn’t get out of second gear it went to 0.3 bar… il give it a long run and see what happens and have the machine running to record the values on the journey

 

[Supernoodle]

Electrical faults (eg open/ short circuit) will be continually tested but plausibility type faults (pressures/temps/flows etc within a range) will only be tested when their specific entry conditions have been met.
So just clearing the fault and going on a short drive does not necessarily mean there is no longer an issue. You do not know if the test entry conditions for that fault have been met yet, so no reoccurrence if the fault could be it's not run yet. If you hadn't cleared the fault code the status byte would tell you, though the likes of the Topdon and icarsoft don't give you raw status, they just show a dumbed down version, either stored, current or pending.

Differential at idle will be close to 0mbar, possibly 10. The differential pressure is as function of the gas flow through the exhaust and the back pressure. So at one or more gas flows it will check that that differential pressure is within a specific range. If not it assumes there is either a leak if it's low or it's overloaded if high.

My father in law had this on his error on his E250 last year. After checking the pipes between sensor and DPF were not blocked or leaking, replaced sensor and it's been fine since

Btw, I assume you saw 0.03bar, not 0.3bar?

 

[Grahamc250]

Thanks for your reply.. just to clarify because iv cleared the fault and driven it for 10 mins I’m well aware it don’t mean the problem is gone for good, I am yet to go on a longer drive but I am assuming it will throw the engine management light up again when I do. Short journey today didn’t throw it up so as you rightfully stated perhaps it hasn’t got to the entry conditions. Yes I was getting 0.03bar when at approx 3000rpm .
I have the new sensor ready to go but thought do I drive it again and see what happens?
As far as your knowledge tho if the sensor is reading a pressure of 0.03 bar am I right in saying that could still be a sensor fault if the 2 pipes are clear without leakage to the dpf ?

 

[Grahamc250]

this is what it currently reads

 

[Supernoodle]

I'm guessing from the exhaust pressure there was quite a load on it whilst also over 3000rpm, so 30mbar seems rather low.

The normal way of testing those sensors is with something like a MityVac hand vacuum/pressure tester. They cost more than a sensor, so if you don't have access to such a device, replacement is often worth a punt.

 

[Grahamc250]

thanks again for your reply nice to have your input.
If the pressure sensor is reading a value then would that still suggest a faulty sensor . When the fault was on before I cleared it there was zero value reading when revving the car. It’s all abit confusing to me il be able to change the sensor easy I’m not clueless when it comes to the labour side of things but can’t get my head around if the sensor is taking a reading so I just change it anyway or am I to suspect an actual leak somewhere …

also I have no idea what is meant by cylinder bank 1 I’m assuming that’s a point along the system but is that from sensor down to dpf? Or beyond that …literally not a clue but if I can save myself the trip to a mechanic and sort with help then great

 

[Supernoodle]

The bank numbering is standard notation used in on board diagnostics. It's so on a V engine where there may be separate sensors in each bank(intake or exhaust), there is standardized way of referencing them.
Even when there is only one bank, or in the case where the sensors are in a combined tract even on a V, the bank notation tends to be used. So bank 1 is superfluous in your case.

If you had no sensor reading whilst the fault was present I guess it's either intermittent and coincidentally read after the clear, or whilst faulted the PID value is frozen (PID is the mechanism for making data available to a diag tool), or the diff pressure function is inhibited as a reaction to the error.

I'm assuming you don't have as means of testing the sensor so I would make sure the pipes ( metal and rubber) between DPF and sensor aren't blocked or damaged, then monitor the values. If the fault comes back change the sensor.

 

[Grahamc250]

I was thinking I’d just change the sensor anyway which I got and see if the pressure value changes after that … would that be a done thing ? Would it need a force regen after new one? Or simply go for a drive and see what happens ? Sorry if I come across thick