DEF/Adblue level frozen despite full tank

[Ctennuc]

Hello all - first post on here.

I have a mazda cx5 2019, 2.2 skyactive diesel, 2WD, 45k on the clock. I had the EML come on (Error P203E) and apparently the adblue level has frozen on the dashboard indicator display (15%) despite filling up to 100% (not overfilled- have checked this). The mechanic (local, reliable) has tried everything, inspected everything and wiring/tank etc, attempted to reset DEF level, battery reset, yet the tank still reads 15% despite being full.

I have not had any issues before with the car, not done any software updates recently either.

The EML has now come back on after reset and I am informed i need a new DEF tank - Approx £1900 all in. Oh dear.

Has anyone got any ideas or had any experience with this issue before as I cannot find a lot on the forum.

Thanks for any advice all.

BW

 

[HyFlyer]

Hello, would there be any way to clean/flush the tank before spending that kind of money on a new one?

 

[Moonlighter]

A mate of mine has a Mercedes diesel SUV and faced this exact same issue. No choice but to have the tank replaced.

The DEF fluid is very corrosive and he was told that even if the components could be cleaned, the tank itself gets brittle over time and attempting to clean it and remove and replace the stuck/damaged internal parts nearly always leads to breakage. He did quite a bit of research and that was the inevitable conclusion.

 

[HyFlyer]

If the DEF system is actually working properly and the only problem is just false reporting of the tank level, I wonder if there would be a way to "trick" the emissions brain with some set resistance on that wire/pin to "see" a fixed level.