ABS Problem

Number 6 · 5th April 2019, 19:41

Well I will give you an update to the problem I am having with the ABS.

Firstly I have stripped and cleaned all the NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- from the back plates of the rear brakes and reassembled them. did the static test, Ignition on ABS light goes out(which it did before)Went for a drive and the light did not come and so I thought Cured....I did about 2 miles and the light stayed out. But when I reached 50 MPH the ABS light came on. Stopped switched off and did the static test again, light out OK, started off and after about 3/4 of a mile, the light came back on again at about 30 MPH....It never comes on as soon as you start moving as I would have thought it would if it was a sensor fault.

So has any of the brainy ones on here have any suggestions ???

Number 6 · 15th April 2019, 16:17

Well after a few red herrings I have finally found the problem with the ABS light randomly coming on...

I have traced it to a broken wire on the front passenger side sensor, Cut the wire, spliced in a new section, and used heat shrink to cover them. It now operates as it should

trikey · 15th April 2019, 17:45

Well done, abs issues can be a pain to diagnose without T4.

Number 6 · 15th April 2019, 18:02

Quote:

Originally Posted by trikey

Well done, abs issues can be a pain to diagnose without T4.

Exactly young man, And in France, it is nigh on impossible to find a T4

Matt70 · 15th April 2019, 20:52

Hi guys, I failed the MOT because of a Anti-lock braking system warning lamp indicates an ABS fault (1.6 (b). My mechanic told me after various checks that I need to repair the ABS ECU system and it will cost £400 +installation but as I know that sometime mechanics try to increase the problems for MOT and take more monay... I would be happy if someone suggest me or another good mechanic in Essex.. Or give me some advise. Thanks

Mike Noc · 15th April 2019, 20:59

Courtesy of French Mike you can check all the ABS sensors and magnetic reluctors in the wheel bearings using a voltmeter, and that should help you check to see if you your ABS modulator is faulty or not.

The signal voltage changes from 1.7V to 0.7V as each magnetic segment passes the sensor, so jack each wheel in turn and slowly rotate it marking the switch points on the tyre wall with chalk. You should end up with 48 chalk marks.

If any gaps are in the same place each revolution then likely a damaged reluctor, and if in random places suspect the sensor or possibly a slightly too big air gap.

Other common failure causes are cable damage to the sensors, a build up of corrosion on the backplate of the rear wheels, or corroded plug pins at the ABS modulator.

Here is a front hub being tested prior to fitting. I use an extension cable made up from some old speaker wire and ABS plug and socket which saves pinning through the ABS cables. It also doubles up to allow any sensor to be plugged in to the OSF so that the speedometer can be used as a diagnostic.

5th April 2019, 19:41	#1
Number 6 This is my second home Rover 75 tourer Club CD/Limo Tints Join Date: Nov 2008 Location: Meneac Posts: 6,759 Thanks: 5,007 Thanked 1,609 Times in 869 Posts	ABS Problem Well I will give you an update to the problem I am having with the ABS. Firstly I have stripped and cleaned all the NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD- from the back plates of the rear brakes and reassembled them. did the static test, Ignition on ABS light goes out(which it did before)Went for a drive and the light did not come and so I thought Cured....I did about 2 miles and the light stayed out. But when I reached 50 MPH the ABS light came on. Stopped switched off and did the static test again, light out OK, started off and after about 3/4 of a mile, the light came back on again at about 30 MPH....It never comes on as soon as you start moving as I would have thought it would if it was a sensor fault. So has any of the brainy ones on here have any suggestions ??? __________________ ] "I started out with nothing, and Ive still got most of it left!"

15th April 2019, 16:17	#2
Number 6 This is my second home Rover 75 tourer Club CD/Limo Tints Join Date: Nov 2008 Location: Meneac Posts: 6,759 Thanks: 5,007 Thanked 1,609 Times in 869 Posts	UPDATE (again) Well after a few red herrings I have finally found the problem with the ABS light randomly coming on... I have traced it to a broken wire on the front passenger side sensor, Cut the wire, spliced in a new section, and used heat shrink to cover them. It now operates as it should __________________ ] "I started out with nothing, and Ive still got most of it left!"

15th April 2019, 17:45	#3
trikey Premium Trader Rover 75 Join Date: Nov 2010 Location: Devon Posts: 33,756 Thanks: 8,837 Thanked 14,831 Times in 8,030 Posts	ABS Problem Well done, abs issues can be a pain to diagnose without T4. __________________ Lest we forget..

15th April 2019, 20:52	#5
Matt70 Regular poster Rover 75 Saloon Join Date: May 2017 Location: Southend on Sea Posts: 60 Thanks: 15 Thanked 9 Times in 5 Posts	Same problem with ABS any suggestion? Hi guys, I failed the MOT because of a Anti-lock braking system warning lamp indicates an ABS fault (1.6 (b). My mechanic told me after various checks that I need to repair the ABS ECU system and it will cost £400 +installation but as I know that sometime mechanics try to increase the problems for MOT and take more monay... I would be happy if someone suggest me or another good mechanic in Essex.. Or give me some advise. Thanks

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15th April 2019, 20:59	#6
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,546 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Courtesy of French Mike you can check all the ABS sensors and magnetic reluctors in the wheel bearings using a voltmeter, and that should help you check to see if you your ABS modulator is faulty or not. The signal voltage changes from 1.7V to 0.7V as each magnetic segment passes the sensor, so jack each wheel in turn and slowly rotate it marking the switch points on the tyre wall with chalk. You should end up with 48 chalk marks. If any gaps are in the same place each revolution then likely a damaged reluctor, and if in random places suspect the sensor or possibly a slightly too big air gap. Other common failure causes are cable damage to the sensors, a build up of corrosion on the backplate of the rear wheels, or corroded plug pins at the ABS modulator. Here is a front hub being tested prior to fitting. I use an extension cable made up from some old speaker wire and ABS plug and socket which saves pinning through the ABS cables. It also doubles up to allow any sensor to be plugged in to the OSF so that the speedometer can be used as a diagnostic.