Mazda 2 Diesel Fault Finding EGR Values

[lemonslap]

I'm trying to find the cause of a flashing DPF light on my 2016 Mazda 1.5 Diesel, it only has a fault code for particulate filter regen frequency and i'm trying to get to the bottom of what's causing this.

I have scanned some of the data points with my diagnostic tool and one reading that seemed odd was the low pressure EGR value, this shows as a -100% error rate however the desired and actual values match when the engine is reved (also the -100% error rate changes). Do you think the vehicle has a faulty EGR? Or is this a red herring?

Scan:



Thanks all for any help

[lemonslap]

Just to update the thread, still haven't really got anywhere with this.

The symptoms are that the DPF is regenerating every 10-20 miles, but I can't find why. Changed the pressure differential sensor as the live reading was varying massively, but the new one does the same so it must be normal. Need to work out a solution as the oil level rises from the max mark to the warning level within 1000miles.

[LordLoveLength]

Can you force a regen? Presumably it never thinks it has completed or the pressure reading is too high.
If you can force a regen, does the exhaust get hot enough on live data? Could be a faulty exhaust temp sensor.
Also as you say pressure reading varies, check wiring to pressure sensor. Turn ignition on and waggle wires whilst monitoring live data. Make sure reading is stable.

[lemonslap]

I did a forced regen at the weekend and ran a injector calibration session. It regened after 20 miles still after this and I could see the DPF g/l increasing to the regen level of 6g/l. One wierd thing did happen while logging live data after this regen, the DPF actual dropped to 0 as expected but the desired only reduced to 3 g/l. The desired then started rising with the actual 3g/l behind it, then all of a sudden they showed the same number.

[stevemcs]

When it was last serviced was the service light and oil quality light reset ?

[ndtman]

lemonslap said:

Changed the pressure differential sensor as the live reading was varying massively, but the new one does the same so it must be normal.

Do you need to carry out an adaptation for the new sensor to be correctly calibrated?

[lemonslap]

stevemcs said:

When it was last serviced was the service light and oil quality light reset ?

Was serviced 1000 miles ago using Millers C1 oil and service/oil indicator reset, as of today the oil dilatation is 100g!

[lemonslap]

ndtman said:

Do you need to carry out an adaptation for the new sensor to be correctly calibrated?

Not on this engine from the information I have.

[Richiec1983]

Hi by any chance did you get to the bottom of this as I have exactly the same problem ?

[lemonslap]

I didn’t get to the bottom of it in the end as I went a different route with the DPF... However after a lot of research I believe the DPF filling fast is cause by poor injection spray patten which requires replacement injectors at about £500 each.. Is your flashing the DPF light? Any running issues?