P220200 - Heating of NOx Sensor

[ragingraven]

Good evening folks!

My 2017 Citroen C4 Grand Picasso II (1.6 BlueHDi 120hp) started screaming about not being able to see NOx sensor with error codes U029D87 & P220087.
This came up after updating engine ECU firmware through official diagbox (v9.268 newest at the time).
From reading around Google and forums I came to conclusion that NOx sensor is dead. Took off mine, from outside it was normal,
but I disassembled it and found lots of white crystals inside the chip.
I suppose that's probably salty water from puddles and that the chip is actually dead.

NOx sensor

So I bought a new NOx sensor from HELLA for 200 Euro. Installed it and initialized it through OFFICIAL Diagbox with token.
I went in this menu order:
EDC17C60 - Repair - Pack Repair - Replacement Parts - Work On Emission Circuit - Replacement of NOx Sensor.
After that errors in Diagbox and SERVICE on dash went away and I took a long ride on highway with 80-120km/h for like an hour. It even turned on regeneration which I don't think it ever did before.

Now the new problem that I have is P220200 Heating of NOx Sensor - Availability time too long? What does this Mean?

Picture from Diagbox

It does not cause SERVICE on dash or anything but it comes up in Fault reading which is annoying.
Doing NOx Sensor Heater Test through Actuator Tests results in successful test with no faults.
Anyone had this issue before?

[myglaren]

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[ragingraven]

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Edited, thanks for letting me know!

[ragingraven]

Problem has been solved!
Went around the wiring for the NOx sensor and there was a broken wire.
Everything seems to be working now.

[Paul-R]

Thank you for letting us know. Broken wires are not an unknown problem.

[MattBLancs]

NOx sensor is dead. Took off mine, from outside it was normal,
but I disassembled it and found lots of white crystals inside the chip.
I suppose that's probably salty water from puddles and that the chip is actually dead.

Hi, quick question - I know it turned out not to be your issue (thanks for confirming that too by the way!) but just to ask:

Was opening up the NOx sensor casing straightforward and do you think, reversible? (I.e. would it go back together again?)

Might be worth a spot of preventative maintenance to open it up and clean out the deposits??

Thanks