Traction warning light question

[DonkeyApple]

I have an old 120D that's used as the local runabout. The traction warning symbol has started flashing up on normal driving and trimming the throttle.

The assumption is that it'll be one of the wheel sensors that requires replacing but as a fault code isn't being generated what's the trick for working out which one?

As the warning appears under throttle I'm working on the assumption that it's one of the rears and as the sensors aren't exactly expensive I'll ultimately replace both but am I being dim not being able to work out which is the actual offending item?

[d_a_n1979]

TBH think you'll need the likes of ISTA to pinpoint which ones failing, unless Bimmerlink can do that (unsure)

At the age they're at; they're not expensive and as you said; replacing both rears or all 4 corners would make sense

Plenty of Wurth Rost Off on the small bolt that holds it in place beforehand (that's if they're that design) to get the thing out, as I know they can seize in

[DonkeyApple]

Thanks.