Rear axle diff lock error

[Dappa44]

This error popped up a few days ago but car drives perfectly, changed the wheel speed sensors as these can often cause issues but the problem is still there.
Read the codes via bootmod3 as my topdon reader is away getting replaced.
No codes shown. Any ideas as I know these can pop codes for random things.

It’s the only error it shows and the car sounds and runs like a dream. 2014 on 40k