ABS 'sensation' through pedal since wheel sensor replaced

[Fastchas]

2012 F31 320D SE - As the title explains, I had the messages 'Tyre Pressure sensor failure' 'ABS Failure' and another (can't remember) message come on my dash. It made the cruise control and 'ECO' drive inoperative. Booked it in to my mechanic whose diagnostics suggested a wheel sensor. This was changed.

Immediately after having the car back, the brake pedal reacts like the wheels are skidding and the ABS is coming on, but only for a split second, and only whilst brushing off speed on approaches to roundabouts, islands etc.

The mech has just had the car back and replaced the wheel sensor as he said they may have supplied the one for a different model. On the way home the ABS was again coming on whilst braking for the island near home.

I will book it back in with the mech but wondered if anyone's got any experience/explanation?

[Ed.Neumann]

Sounds more like the reluctor ring than the sensor. That is the symptoms you tend to get.

These are cheap, like £5-10, but can be a bit of a pig to fit.

I would check it for any debris first, you can often get something stuck between the gas which can cause what you are experiencing.

[Fastchas]

Update on this.
Just took my car to a BMW indy who had it for a couple of hours to run tests. He say the battery is giving out power surges, spiking around 15-15.5v.
It should be about 14-14-4v max. The electrics cant cope and throwing up all kind of errors.
Advised to get a new battery, but equally, it could be the alternator.

[jj.]

Sounds to me like a loose/Dirty ABS sensor. Had it once on an A4, when coming to a stop the last 10mph - 0, abs kicked in but only on a real gentle pedal. Checked all 4 found one had worked a little loose, tightened it up all fine.
jj

[rottenegg]

Fastchas said:

Update on this.
Just took my car to a BMW indy who had it for a couple of hours to run tests. He say the battery is giving out power surges, spiking around 15-15.5v.
It should be about 14-14-4v max. The electrics cant cope and throwing up all kind of errors.
Advised to get a new battery, but equally, it could be the alternator.

F3x have battery management and don't rigidly stick to 14V. 15V wouldn't concern me, but how old is the battery? If you get Bimmerlink, you can view the battery health. There are always loads of 'info errors' relating to CAN delays and voltage discrepancies with F3x's, but so long as nothing is sitting in 'permanent errors', it's fine.

Did the garage fit a genuine ABS sensor or a pattern one? Over 35 years experience of German cars, pattern electronics are just garbage. They're not calibrated or QC'd like genuine parts are. If a cheapy sensor was fitted, the ABS ECU might not like the signal. As others have said, it could also be a corroded reluctor ring but I would check what part was fitted in the first instance.