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Anti Lock ECU replacement

NMV 1E
Snr Member
Posts: 919
Joined: Fri Apr 17, 2009 9:26 pm
Location: Lydiate, Merseyside.

Re: Anti Lock ECU replacement

Postby NMV 1E » Thu Feb 21, 2019 9:26 pm

I've also found this very useful in the past .......... http://www3.telus.net/bc_triumph_registry/smoke.htm ;)
Life begins at Forty !... I was born with nothing, I seem to have most of it left.


2006 Baby Blue Hyundai Getz 1.4 CDX, Auto (yes I know, I know, but you'd be surprised, I was !)
1989 White and Navy Blue V.W. Golf Cabriolet (G.T.i.)

MrScruffs
Posts: 14
Joined: Thu Jan 31, 2019 2:18 pm
Location: West Sussex

Re: Anti Lock ECU replacement

Postby MrScruffs » Fri Feb 22, 2019 3:56 pm

Thanks everyone. I replaced the front right sensor and went for a short drive. Anti Lock light has extinguished and is working as expected.

MOT booked for Monday!

I’m already contemplating where the first trip out should be to (apart from the petrol station)...
--
1989 Daimler 4.0 in Dorchester Grey
1995 Land Rover Defender 90 in many colours

naki_k
Super Moderator
Posts: 28578
Joined: Sun Feb 21, 2010 9:25 pm
Location: Kirton, nr Boston, Lincolnshire

Re: Anti Lock ECU replacement

Postby naki_k » Tue Mar 05, 2019 2:27 am

MrScruffs wrote:Thanks everyone. I replaced the front right sensor and went for a short drive. Anti Lock light has extinguished and is working as expected.

MOT booked for Monday!

I’m already contemplating where the first trip out should be to (apart from the petrol station)...


Great news.
Did you test it first to know that was the failed unit?

Onto the next issue then?
88 3.6 XJ6 PDH/CEM
90 Range Rover Vogue SE 3.9 V8 LPG
91 4.0 XJ6 Manual
92 4.0 XJR Manual
92 4.0 XJR
93 3.2s - 4.0 Manual conv
93 4.0 Sovereign
93 6.0 XJ81 DD6 x2
93 6.0 XJ81 XJ12
94 4.0 XJR
94 4.0 Daimler
96 4.0 X306 XJR
96 4.0 X300 D6
97 4.0 X300 Sport Manual
2000 LR Discovery ES TD5 A
Breaking 40/ 300

MrScruffs
Posts: 14
Joined: Thu Jan 31, 2019 2:18 pm
Location: West Sussex

Re: Anti Lock ECU replacement

Postby MrScruffs » Wed Mar 13, 2019 10:18 pm

Hmm, can’t believe I missed your reply...

Yes I did test the sensor first. I’m freshly armed with a multimeter!

The car passed the MOT with a few little advisories, but nothing serious. However I got one short error free trip out before the door ajar light started to remain on at all times - probably due to my youngest Son slamming the door as if it were my Land Rover! I’m sure it would have failed soon enough anyway without his help.

Of course now the interior lights won’t turn on when any of the doors are opened. From reading other posts on here it seems like a slightly fiddly job to extract the sensor from the door, so that’ll have to wait for some better weather.

In the meantime she’s had a service, and a new distributor cap and rotor are waiting for the weekend. The fuel filter is stuck on due to rust, but I’ll soak it in wd40 a few times and hope for the best...
--
1989 Daimler 4.0 in Dorchester Grey
1995 Land Rover Defender 90 in many colours

Bruce69
Posts: 76
Joined: Wed Apr 04, 2018 2:16 pm

Re: Anti Lock ECU replacement

Postby Bruce69 » Wed May 15, 2019 7:00 pm

katar83 wrote:My 94 ABS ECU was proper knackered, solder joints clearly cracked inside. I suspect earlier ECUs might have the same fault but resoldering it fixed is straight away. You will need to take the car for a drive to clear ABS codes.

Recently had the ABS light come on permanently and I'm getting no flashes on the blink test, so I suspect the ECU. So I read this thread with interest.
Having taken the screws out of the ECU casing the sides seem to be glued on. Do I need to use a bit of brute force to prise them off?
XJ40 3.2 LPG 1991 54k
Jeep Grand Cherokee Overland 4.7 V8 HP LPG 2002
Dodge Charger R/T 1969

katar83
Posts: 2728
Joined: Tue Aug 23, 2011 11:17 am
Location: Cambridge

Re: Anti Lock ECU replacement

Postby katar83 » Wed May 15, 2019 9:39 pm

Sadly I don't remember anymore as it was 6+ years ago but cant remember anything glued in a Jag, I suspect it should split easily with a bit of force.
1997, 4.0 LWB X300 - Unlucky car but still a daily driver.
1988, 3.6S XJS - Never ending restoration project.
1994, 3.2S X300 - Accident damaged, October 2015. Gone!
1994, 3.2S XJ40 - Long gone.

Bruce69
Posts: 76
Joined: Wed Apr 04, 2018 2:16 pm

Re: Anti Lock ECU replacement

Postby Bruce69 » Thu May 16, 2019 9:11 pm

Well, I managed to prise the side panels off the ABS ECU. I assume the solder joints that crack are between the connector block and the PCB. If so mine look fine.

Performing the ABS fault diagnosis by the manual (Ch 70, p.17), the Main Relay was shown to be faulty (1.5M ohms instead of 100 ohms) but I can't find it! Well, at least I'm not sure if I have or not.

The manual says (in Electrical Harnesses, Ch 90, p.48) Main Relay (RS97, natural base) is by the RH Blower Motor (apparently under the drivers dash), and the ABS ECU Relay (RS103, blue base) and the ABS Pump Relay (RS96, yellow base) is in the Drivers Footwell. Looking at the picture you can see there are blue, yellow and natural bases but the wire colours to the natural base doesn't seem to match the wiring diagram.

Can anyone tell me if this is the ABS Main Relay?
Image
Last edited by Bruce69 on Fri May 17, 2019 8:54 am, edited 1 time in total.
XJ40 3.2 LPG 1991 54k
Jeep Grand Cherokee Overland 4.7 V8 HP LPG 2002
Dodge Charger R/T 1969

old del boy
Posts: 6929
Joined: Thu Jul 10, 2008 9:29 am
Location: Kent

Re: Anti Lock ECU replacement

Postby old del boy » Fri May 17, 2019 1:11 am

Well having checked the jaguar manual myself i would agree that it is , the wiring , from what i can see in the picture does more or less match and on checking the other model years they all are much the same ,

Derek..
'93 4.0L Daimler, solent blue,
'93 4.0L Daimler, Westminster,
'85 2600 Rover sd1 vdp oporto.

Bruce69
Posts: 76
Joined: Wed Apr 04, 2018 2:16 pm

Re: Anti Lock ECU replacement

Postby Bruce69 » Fri May 17, 2019 8:33 am

Thanks old del boy.

I extracted the relay, and like you say some of the wires do match up (why not totally?!) and then I spotted a part number on the side (DAC7151), which I thought would identify a generic relay but actually correctly identifies it as the ABS Main Relay.

Armed with that information, an order will be made for a new one.
XJ40 3.2 LPG 1991 54k
Jeep Grand Cherokee Overland 4.7 V8 HP LPG 2002
Dodge Charger R/T 1969

old del boy
Posts: 6929
Joined: Thu Jul 10, 2008 9:29 am
Location: Kent

Re: Anti Lock ECU replacement

Postby old del boy » Sat May 18, 2019 12:03 am

Who knows why some are different , there has been mistakes and omissions that we have discovered over the years so the manual is not infallible , i think at the end of the day you have to rely on process of elimination and make an educated guess on some things , i've found though that the Jaguar manuals , especially the supplementary model information manual jhm1130 particularly good and has more detailed electrical diagrams ,

Derek..
'93 4.0L Daimler, solent blue,
'93 4.0L Daimler, Westminster,
'85 2600 Rover sd1 vdp oporto.