Hi all,

I've done 3 pics, all with the engine light off atm. Hopefully will get ones with the engine light on tomorrow 🤣 took me awhile to figure all out.

Kind regards

Ross

 

Something is seriously wrong with that differential pressure reading.

Started ok at idle.  But 819kPa is ridiculous lol.  And the fact that it seems to be all or nothing for most of the journey is definitely wrong.

I'd suspect the sensor is either a cheap pattern part or the wrong one for this car.

 

This might be a pressure sensor fault? Should I try a different one? It makes sense if the engine light keeps going on every so often. 

 

35 minutes ago, Xadacu said:

This might be a pressure sensor fault? Should I try a different one? It makes sense if the engine light keeps going on every so often. 

 

Yeah, it should be more like 8kPa than 800.  I'm fairly sure the engine wouldn't even run with that much exhaust restriction, so would say the issue is with the sensor readings rather than a mechanical fault.

Best thing to try is swapping the sensor for a decent one and then run the same live tests again.  Trouble is, they're super expensive new and genuine.

https://shop.ford.co.uk/products/focus-c-max-galaxy-s-max-mondeo-exhaust-dpf-sensor

Don't suppose you know anyone else with a diesel Ford around the same age?  If so you could borrow their sensor just to confirm the fault.

Might have found one thats a ford genuine from a scrappy, hopefully I can grab that as it's a faction of the price then go from there 👍

With those readings the problem is likely to be either a faulty Sensor, faulty Wiring or connector or a PCM fault rather than anything being wrong with your DPF.

To put things in perspective, with a lot of cars if the Differential Pressure goes above 15 Kpa for a certain amount of time then the PCM will flag a Fault and will not allow a Static Regeneration to happen for safety reasons.

1 hour ago, Tizer said:

With those readings the problem is likely to be either a faulty Sensor, faulty Wiring or connector or a PCM fault rather than anything being wrong with your DPF.

To put things in perspective, with a lot of cars if the Differential Pressure goes above 15 Kpa for a certain amount of time then the PCM will flag a Fault and will not allow a Static Regeneration to happen for safety reasons.

If this doesn't work with the sensor and it comes a pcm fault not much I can do to fix the problem? 

1 minute ago, Xadacu said:

If this doesn't work with the sensor and it comes a pcm fault not much I can do to fix the problem? 

If the Sensor is ok it could be a Wiring fault anywhere between the Sensor and the PCM, including any connectors as well as a faulty PCM or Software fault in the PCM.

All the above are very difficult to diagnose.

Hi all,

Just an update I got a genuine ford sensor and fit it in this week with also sorting out my bonnet as I couldn't get into it as it seized up 🤣. I reset the sensor and the engine light was off, after the 3rd time tuning on the car, I went 100 yards and it came on again basically doing the same as it was doing before, so it can't be that. I'm guessing it's a wire fault or pcm now as I'm having no problems apart from the engine light coming on every 3rd time I switch it on after turning off the light. What's the best way to go from here?

Thanks.

Have you done another live data graph?  Same reading as before?

Next up is wiring tests with a multimeter.  Basic voltage tests first. Should be 5v on one pin, 0v on another pin (earth) and a changeable voltage on the third pin (signal).

Hopefully one of those will show an error.  If not, that only really leaves the PCM which isn't cheap to replace or easy to access.

16 hours ago, TomsFocus said:

Have you done another live data graph?  Same reading as before?

Next up is wiring tests with a multimeter.  Basic voltage tests first. Should be 5v on one pin, 0v on another pin (earth) and a changeable voltage on the third pin (signal).

Hopefully one of those will show an error.  If not, that only really leaves the PCM which isn't cheap to replace or easy to access.

Hey, which wiring will I have to test? I'm starting to think it's the pcm. Someone did say to me that I might of brought an illegal car as they heard that you can blow out the filter then remap the engine ? I dunno much into it but didn't know you could do that. It's been 2 months and still drives fine just the engine light keeps coming on every third time still.

 

32 minutes ago, Xadacu said:

Hey, which wiring will I have to test? I'm starting to think it's the pcm. Someone did say to me that I might of brought an illegal car as they heard that you can blow out the filter then remap the engine ? I dunno much into it but didn't know you could do that. It's been 2 months and still drives fine just the engine light keeps coming on every third time still.

Test at the plug for the pressure sensor.

It is possible to empty the DPF and remap the ECU, however that remap should stop the engine light coming on by either fooling the DPF sensor or switching it off altogether.  It could be a 'bad' remap though.

If you want to check for a gutted DPF - first have a visual look at the can, see if there are any poor welds that don't look factory.  Second, use a mechanical pressure tester to check the pressure on each small solid DPF pipe.  The lower pipe should have slightly less pressure, if it is being restricted by the DPF core (effectively breathing through a brick!).  Third, you can remove the DPF and use a mirror or bendable camera to look inside.  The ends of the DPF are bent on these so can't just look straight through them.

Have you sorted any of the other dtcs .

Are they still present? If so
Have you had the cluster already checked/re-soldered?

just a thought

On 6/30/2023 at 7:36 PM, TomsFocus said:

Have you done another live data graph?  Same reading as before?

Next up is wiring tests with a multimeter.  Basic voltage tests first. Should be 5v on one pin, 0v on another pin (earth) and a changeable voltage on the third pin (signal).

Hopefully one of those will show an error.  If not, that only really leaves the PCM which isn't cheap to replace or easy to access.

Hi all, I tried the pins and they seem to be ok, changed the sensor again and still getting the same EML after 3 key turns and trips to and from work. Looks to me it's a pcm fault would it be possible to try and reset it via forscan? 

I did get these images from when the EML was on, I will get the parking sensor sorted next 🤣

Regards

 

Not that I don't trust your diagnosis but...   I'd recommend going to auto electrician to have them check the wiring for the sensor.

If it's a PCM fault you'll have to send it away for internal repairs.  Alternatively you could buy an 'unlocked' PCM to swap with yours if you need the car every day.  I really would have the wiring double checked first though.

 

23 minutes ago, TomsFocus said:

Not that I don't trust your diagnosis but...   I'd recommend going to auto electrician to have them check the wiring for the sensor.

If it's a PCM fault you'll have to send it away for internal repairs.  Alternatively you could buy an 'unlocked' PCM to swap with yours if you need the car every day.  I really would have the wiring double checked first though.

 

I can get them to check it's just the garages I've had check the car so far basically don't want anything to do with the filter and trying to find the fault. It's weird as I'm paying them to do it 🤣 I dunno maybe resetting the pcm might work also? 

Lol, you need an auto electrician, not a lazy fitter!

I don't think the PCM can be reset like other modules.  I'm fairly sure this is a physical issue rather than a software fault, unless it's had a dodgy remap as suggested before.

Be very careful if there is a PCM reset on Forscan as you could end up bricking the PCM if the procedure isn't followed  properly.

I believe yours is a mk 2.5 which can develop can bus connection issues.

If u codes are still being recorded, to replace any hardware etc would not be my choice before rectifying the cab bus issues.

it can affect various modules.