ABS Sensor fault code - after tyre and suspension change?

[Triode]

Hello,
I have been working on my z3 front suspension but before I started that I had the rear tyres changed last year, when that was done, the ABS and circle line thingy light with a yellow triangle and ! sign in the middle comes on the dash board permantly. I thought hey-ho, I need to get the suspension done anyhow so will work my way round to looking at the ABS sensors and replacing them all.

I have a ECU reader (recommended from this forum) and while the front bearing was off the car I took a reading and the only fault codes are the rear and front right ABS sensors. Have just got the right side suspension done with new BOSCH sensor fitted (to the front only) and the fault won't clear. The ECU reader can do a live view, so chose that option, jacked up the right front wheel and it see's it going round - 2km per hour etc and changes depending on how fast I spin it. So why are the lights showing on the dash board and why can't I clear my ECU fault codes - at least the front cause codes - that is a brand new sensor.

Should I take it in to a BMW dealer to have it looked at do you think - I need finish off the other suspensions but when all done and all sensors have been renewed, will I have a problem that all 4 wheels will be showing fault codes? I'm a bit baffled? Any suggestions?

Cheers

Adam

 

[Old MrT]

I ended up changing all four sensors, I had a fault code for the N/S/R but after changing that, it kept coming up with intermittent codes on the other three wheels. Once I'd changed all four it was fine so I think it's best if they're all matched, also make sure that the trigger wheels are all clean.

 

[Jack Ratt]

After fitting new wheel sensors drive the car as normal and they should reset themselves within a few hundred meters. Unless of course you have a faulty brake ECU.

 

[Mike Fishwick]

Also make sure that the battery is full charged, as the ECU is voltage-sensitive - I find that even a fortnight without use will trigger the warning lamps until the battery is fully charged again. How old is the battery?

 

[Triode]

Hi, thanks for the replies. I did take her for a drive round the block and the battery is fully charged and about a year old. The car is off the road at the mo, I've changed out the suspension on one side plus the wheel bearing and sensor and will be working my way round the others doing the same including replacing the ABS ring on the rear drive shaft thingy - hopefully having her ready to go on the road next year, so this year is spending a bit of love and attention on her. I am getting a reading from the new and old sensors so maybe it is an ABS ECU issue but odd that changing the rear tyre seemed to kick it off??? I guess there's no other checks I can do, I've looked at the fuses in the fuse box and they are fine.......

 

[Kenhayes247]

I ended up changing all four sensors, I had a fault code for the N/S/R but after changing that, it kept coming up with intermittent codes on the other three wheels. Once I'd changed all four it was fine so I think it's best if they're all matched, also make sure that the trigger wheels are all clean.

What are the trigger wheels?

 

[t-tony]

Just another name for the toothed ring on the driveshaft, or hub, which the ABS sensor picks up on.

Tony.

 

[Kenhayes247]

Just another name for the toothed ring on the driveshaft, or hub, which the ABS sensor picks up on.

Tony.

Thanks Tony