Bmw e46 DSC & ABS lights on together

Agricola

Recently been getting both these dash lights on my 320d. Usually what happens is they will come on during a journey, then seem to reset themselves once I've had the engine off for awhile and are gone off again for the return trip.

I'm also getting a rumble through the brake pedal when they are on, sort of like you get when you brake on ice, like a juddering sensation. I assume the abs going haywire?

Have had all the sensors out, the front ones were completely clogged with gunk and was were the teeth on the hub that they rub along beside. Cleaned everything with brake cleaner, blew it out with compressed air and left the battery off over night to try to clear the fault codes.

Was delighted when the lights were gone on the first test trip, but they soon reappeared after afew miles.....

Is there anything else worth trying before I go off to get the fault read and maybe buy replacements?

biko

Not really, get codes read and go from there.

fitzeyboy.

Could be the one or both the abs pressure sensors on the master cylinder. You need codes read and live data from the abs unit. Both sensors should read the same.

Agricola

Yeah will get the codes read asap so. If it is the one or more of the sensors down at the wheels, is it a pretty handy DIY job?

Renegade Mechanic

BMW's "Dynamic Stability Control relies on the ABS system information to tell which wheels aren't behaving, so it's very likely just one fault causing all the lights. Unfortunately you'll have to scan it to find said fault.

If it was just the DSC light on, it could be a braje pressure sensor, steering angle sensor or even (believe it ir not) the steering alignment gone out, apparently realised when the steering wheel angle doesn't match the allowed speed differences of all four wheels.

edit: speaking of which, if you've had tyres recently, check all four sizes

Agricola

Havent had any tyres recently but they are all definitely the same size!
Yes, anything I've seen suggests that this is one or more ABS sensors that have packed in. Will probably wait til next week when a couple of my local indie garages are open again to get the scanner on it.

Agricola

Found someone open today who cleared the codes for me. The traction or ABS light didnt immediately come back on, thought it just needed to be cleared and all was now well, but they popped up again 100m down the road from the garage!

Went back to the guy, got them re-scanned and it indicated the front left ABS sensor and the steering angle sensor. He was under the impression the steering angle sensor might be flagging up an error because of the ABS being faulty and just replacing the abs should sort everything. Just had a look there at steering angle sensors and they aren't cheap and are a bit of a hoor to fit.

Anyone know if he might be right, or will I probably be looking at ordering both?

Foxhole Norman

Agricola wrote: »

Found someone open today who cleared the codes for me. The traction or ABS light didnt immediately come back on, thought it just needed to be cleared and all was now well, but they popped up again 100m down the road from the garage!

Went back to the guy, got them re-scanned and it indicated the front left ABS sensor and the steering angle sensor. He was under the impression the steering angle sensor might be flagging up an error because of the ABS being faulty and just replacing the abs should sort everything. Just had a look there at steering angle sensors and they aren't cheap and are a bit of a hoor to fit.

Anyone know if he might be right, or will I probably be looking at ordering both?

Replace the front left sensor first. Very common faults on this era BMW, simple and cheap to fix, you can do it yourself with a Hex Key set, genuine sensors go for about 60-70 but can get spurious cheaper.

Alanstrainor

Foxhole Norman wrote: »

Replace the front left sensor first. Very common faults on this era BMW, simple and cheap to fix, you can do it yourself with a Hex Key set, genuine sensors go for about 60-70 but can get spurious cheaper.

Had to replace the sensor on mine a year ago or so. Not a bad job, except mine was so old that it had fused to the house. Had to get a dremmel to it to get it out.

Foxhole Norman

Alanstrainor wrote: »

Had to replace the sensor on mine a year ago or so. Not a bad job, except mine was so old that it had fused to the house. Had to get a dremmel to it to get it out.

I was lucky with the Imola E39, was perfectly free on it!

Agricola

I was going to get an interchangeable sensor but apparently the front left and right on this year of 320d are different. Will give it a go when it arrives next week and hopefully when I get the codes cleared again, that will do it.

From reading about the steering angle sensor, it rarely seems to need replacing, just resetting / recalibrating with a scanner once the ABS is done.

Foxhole Norman

Agricola wrote: »

I was going to get an interchangeable sensor but apparently the front left and right on this year of 320d are different. Will give it a go when it arrives next week and hopefully when I get the codes cleared again, that will do it.

From reading about the steering angle sensor, it rarely seems to need replacing, just resetting / recalibrating with a scanner once the ABS is done.

Yeah when I got a second hand ABS unit for mine I had to code it to the car and reset the angle sensor, never usually an actual issue.