How to replace sensors for ABS

Have you had a proper diagnostic check to confirm that it is a wheel sensor that is faulty?

I've only ever done the front wheel sensors on the E39 but the same applies to the rear.

Jack up at cill jacking point only, no where else.  Remove wheel.

Sensor is bolted to the hub at the 5 o'clock position or 7 o'clock position depending on the side of the car.  It will be held in with one or two 5mm Allen key bolts.

Scrape out any muck and crud from the Allen key recess with a small screwdriver.  I then gently tapped in the allen key bit from my socket set into the recess as my bolts were slightly rusted.

Spray WD40 on bolt area.  Loosen bolt, spray more WD40 then losen by 1/2 turn, tighten by 1/4 turn, loosen by 1/2 turn and so on using WD40.  This should help break up any rust of muck on the threads.

Once bolt(s) are removed the sensor should just pull out from the hub.  Disconnect wiring from within splash box fixed to inner wing/wheel arch.  Disconnect wiring from mounts on shocker/suspension arms etc.

Refitting is reversal of removal except you swear in different places and put some copepr grease on the bolts of the sensor.

HTH

Andrew