E38 728i - Braking issue and warning lights.

[richard300]

Just picked up a 2001 BMW 7-series that I saw on e-bay. Was informed by the advert that there was an issue and that the ABS/Traction control light came on once on the move (but would reset when the car was switched off for a while.

And low and behold as soon as I hit about 30mph the Traction control, ABS and Brake pad? warning lights all came on (All Amber lights) but what also happened, which I was not quite expecting, was a pulsing, knocking noise whilst I was braking.

A friend will be attaching his Snap On fault code reader to the car, but that is going to be a week away.

So i was just wondering in the interim, if any of you guys had any ideas what the problem could be, so i can budget for the repair (initially I was hoping it might have just been an ABS sensor, but with the pulsing/knocking noise i think not?

Regards,

[4rephill]

Pulsing/knocking noise whilst braking will be the ABS cutting in due to a system fault with the ABS/ASC control unit or the ABS hydraulic unit.

If it were just an ABS wheel sensor then the ABS and traction control would cease to operate (the car would still be drivable though).

[sparks_E39]

Could be the ABS module.. repair is £200ish, replacement around £500. When my ABS sensor went the speedo stopped working. Whatever you find broken, replace it with genuine BMW parts... these cars don't like aftermarket stuff.

[Ben0680]

Had same issue with my 2001 e38 728i found that it was the abs pre charge motor was stuck solid replaced with a second hand used one and has been fine since light doesn't come on any more always used to soon as i drove past 25 30 mph ish