brake assist service warning

bobdabuilda · Feb 8th, 2012, 18:44

Just had this warning come up on the d.i.s when I started her up at 5pm. The car had been parked up in the staff carpark since 8am and didn't show the warning on the drive to work. New brake pads,hb shoes and discs fitted all round in June last year and everything seems to be working ok....
Is there anything I can check other than brake fluid reservoir or is it a recommended return to stealers for a check?

volvozx6r · Feb 8th, 2012, 20:25

Could be brake pedal sensor or the steering angle senor at fault.

FXMunkee · Feb 9th, 2012, 09:51

I got this yesterday but mine popped up just as I was going round a small roundabout "enthusiastically". On restarting afterwards it had disappeared (no messages).
Anything to worry about? Do I need to get the codes read?

Ron_XC90 · Feb 9th, 2012, 09:59

If it happened around a fast corner I would start by checking the brake fluid level as per Bob's first point of check

bobdabuilda · Feb 9th, 2012, 22:42

The message hasn't returned since that first occurrence yesterday. Maybe it was the cold!

greenfingers · Feb 10th, 2012, 12:07

I would bet it is an ABS wheel sensor.

Had this happen twice last winter - with my van and with the old ML270.

The nuisance is that as an intermittent fault, Sod's law suggests it will not show up when you take it for diagnosis. The other thing I found tricky was testing the sensors and cables, since it is not a simple electrical resistance check. You can try to measure the induced magnetic flux caused by wheel rotation, but getting an accurate reading is not easy, and the operational parameters of the sensor are quite unforgiving.

In the end, I just bought a new sensor and eventually eradicated the fault by trying it on different wheels until the fault was gone. The sensors have no moving parts, but do seem to fail due to cold weather and possibly water ingress too.

volvozx6r · Feb 10th, 2012, 20:09

If you go to your volvo dealer they will read the error codes. there is a software update.for the steering angle sensor.

Sportwag · Feb 10th, 2012, 20:34

Quote:

Originally Posted by volvozx6r

If you go to your volvo dealer they will read the error codes. there is a software update.for the steering angle sensor.

Hi, is this a recent update i.e. since Dec? I have been getting Anti Skid following a software update in December and it came on the other day just turning the wheel.

volvozx6r · Feb 12th, 2012, 01:19

Did you have the service software update or the steering angle sensor update? The update has been out for a while now. If the sensor software update was done and calibrated correctly then it could be the sensor at fault. Id get the codes checked anyway as it may be a different fault.

Feb 8th, 2012, 18:44	#1
bobdabuilda Premier Member Last Online: May 31st, 2022 11:32 Join Date: Nov 2009 Location: south	brake assist service warning Just had this warning come up on the d.i.s when I started her up at 5pm. The car had been parked up in the staff carpark since 8am and didn't show the warning on the drive to work. New brake pads,hb shoes and discs fitted all round in June last year and everything seems to be working ok.... Is there anything I can check other than brake fluid reservoir or is it a recommended return to stealers for a check?

Feb 9th, 2012, 09:59	#4
Ron_XC90 Master Member Last Online: May 19th, 2014 11:33 Join Date: Dec 2007 Location: Redditch View Photos By: Ron_XC90	If it happened around a fast corner I would start by checking the brake fluid level as per Bob's first point of check __________________ Chrysler Grand Voyager 2.8 CRD Limited 2010 XC90 D5 SE Geartronic, MY2008 (Now sold) Mitsi Pajero 2.8TD Super Exceed '96 (My Toy) Member of the Gloucestershire & Worcestershire 4x4 Response group. www.gw4x4r.co.uk

Feb 8th, 2012, 20:25	#2
volvozx6r Junior Member Last Online: Dec 22nd, 2012 18:54 Join Date: Feb 2012 Location: salisbury	Could be brake pedal sensor or the steering angle senor at fault.

Feb 9th, 2012, 09:51	#3
FXMunkee New Member Last Online: Mar 16th, 2018 11:42 Join Date: Jan 2012 Location: Wigan	I got this yesterday but mine popped up just as I was going round a small roundabout "enthusiastically". On restarting afterwards it had disappeared (no messages). Anything to worry about? Do I need to get the codes read?

Feb 9th, 2012, 22:42	#5
bobdabuilda Premier Member Last Online: May 31st, 2022 11:32 Join Date: Nov 2009 Location: south	The message hasn't returned since that first occurrence yesterday. Maybe it was the cold!

Feb 10th, 2012, 12:07	#6
greenfingers Junior Member Last Online: Sep 2nd, 2013 11:54 Join Date: Jun 2011 Location: Oxford	I would bet it is an ABS wheel sensor. Had this happen twice last winter - with my van and with the old ML270. The nuisance is that as an intermittent fault, Sod's law suggests it will not show up when you take it for diagnosis. The other thing I found tricky was testing the sensors and cables, since it is not a simple electrical resistance check. You can try to measure the induced magnetic flux caused by wheel rotation, but getting an accurate reading is not easy, and the operational parameters of the sensor are quite unforgiving. In the end, I just bought a new sensor and eventually eradicated the fault by trying it on different wheels until the fault was gone. The sensors have no moving parts, but do seem to fail due to cold weather and possibly water ingress too.

Feb 10th, 2012, 20:09	#7
volvozx6r Junior Member Last Online: Dec 22nd, 2012 18:54 Join Date: Feb 2012 Location: salisbury	If you go to your volvo dealer they will read the error codes. there is a software update.for the steering angle sensor.

Feb 12th, 2012, 01:19	#9
volvozx6r Junior Member Last Online: Dec 22nd, 2012 18:54 Join Date: Feb 2012 Location: salisbury	Did you have the service software update or the steering angle sensor update? The update has been out for a while now. If the sensor software update was done and calibrated correctly then it could be the sensor at fault. Id get the codes checked anyway as it may be a different fault.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)