ABS Shuttle Valve Repair

DWB

Well-known member
Feb 26, 2005
62
0
Bellingham, WA
To deal with the three amigos on my '99 DII, I'm about to attempt the repair in this write-up to "rewire" the ABS shuttle valves, and wondered if anyone has tried it here, and if so, how it worked out?

http://www.landroverclubvi.com/abs-mod.html

I pulled the SLABS fault code(s) and the only one was "Shuttle Valve Electrical Failure." I figure it's worth a try?
 

GoodJava

Well-known member
Mar 24, 2006
56
0
San Marcos CA
The author of that link is user jycsalas (Josh Salas) who is also the moderator over at LandRoverForums. Check out related thread there:

http://landroverforums.com/forum/showthread.php?t=26847

My '03 Discovery is currently in the shop having the bypass wire installed, along with brakes, overlay harness, and other minor bits addressed. I tried to do the bypass wire myself but found that attempting to get the SVS plate off was incredibly tight work - no space for me to get the 4mm hex key into position other than the first bolt on the left side of the ABS.

I showed my local shop the abs-mod link and they were 'skeptical'. The agreed to install but warned they cannot warrant or guarantee the outcome. My fault codes were 11.4 (shuttle valve electrical) and 8.4 (rt side front overlay harness). I am hoping the bypass wire gets rid of the 11.4.

Good luck.
 
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jycsalas

Well-known member
Mar 6, 2009
159
0
Im very happy to hear it worked for both of you. You should add "amigos free since mm/yy" in your signature line.
 

Allen Skillman

Well-known member
Feb 27, 2007
103
0
AT THE PUB
To deal with the three amigos on my '99 DII, I'm about to attempt the repair in this write-up to "rewire" the ABS shuttle valves, and wondered if anyone has tried it here, and if so, how it worked out?

I did this to mine 6 weeks ago with the help of Jimmyjams and it fixed the issue.... TC works like new. Tested in 24" of snow last weekend in Va.
 

midessa7

Member
Sep 18, 2008
8
0
Hi, new here. I did the bypass repair myself and the three little bastards have been gone since. It was pretty easy.

midess7
 

DWB

Well-known member
Feb 26, 2005
62
0
Bellingham, WA
Thanks to everyone who replied to this post, it gave me the extra confidence to go ahead with the repair, which I did today. I took the shortest route and removed the shuttle valves by just unfastening the ABS module and raising it up as high as I could. I found I could get it up higher than in the write-up using a narrow block of wood under the ABS body without blocking the shuttle valve, which made it very easy to get a small ratchet with a 4mm bit underneath to remove the three bolts. I know some had trouble with this step, but I found it easy (PM me and I'll send a pic). I then followed the write-up precisely after checking the resistance on the shuttle valves, which were right in spec. When finished went for a test drive, ran the hill decent a bunch (which would have previously prompted a visit from the amigos) and to my surprise ? NO VISIT!! I?m cautiously optimistic ? I drive in a fair amount of snow here in the PNW and will be glad to have reliable ABS back. Adios amigos?
 
B

brooksa

Guest
I did this also and have been Amigo free since October, everything seems to be working fine.
 

JohnB

Well-known member
Oct 18, 2007
2,234
1
Oregon
I'm skeptical of this procedure. The reason for my concern is that I believe that from what I understand is that the grounding is the issue. I'm pretty sure that all those little solenoids in the modulator are activated via the wabco control unit by ground signals. Like fuel injectors the power isn't pulsed the ground is.

Jerry rigging the ground may be great to get the amigos to not recognize a ground fault but what happens when you hit the OH Shit pedal and your ABS goes wacko.

I may be wrong and maybe the solenoids are not ground activated. Still I'm not about to do this fix ever.
 

mbrummal

Well-known member
Jan 23, 2009
2,849
0
Montgomery, AL
the ground used in option b is only for the signal from that switch. It isn't modifying the circuits for the solenoids at all. I think you could connect the ground to one of the ground wires in the harness (I would anyway).
 

GoodJava

Well-known member
Mar 24, 2006
56
0
San Marcos CA
Just got back from a 5 day trip to Salt Lake City. We had two days of snow and lots of opportunity to test both the brakes and the traction control. I am VERY happy to say both systems performed flawlessly since performing option B (bypass wire) on our '03 Discovery. If Josh lived in San Diego I'd buy the first couple rounds.
 

jycsalas

Well-known member
Mar 6, 2009
159
0
Thanks for the kind words everyone. The ground on that bypass for the YG wire is what the SLABS ECU uses to monitor the resistance of the SVS only. It doesn't have anything to do with the solenoids inside the modulator. I personally did not want to tap into the ground wire in the actual harness but i don't see how that wouldn't work either way. Once the slabs ecu senses either; NO BRAKE, PARTIAL BRAKE, or OH SHIT HOLD ON TO SOMETHING BRAKE, the SLABS ecu then tells the solenoids how to perform. Hope that clarified things.
 

DiscoArt

Well-known member
Nov 14, 2009
97
0
Did the fix two weeks ago and it is working great. ABS and traction control work fine.
 

yuenie

Member
Jul 29, 2008
20
0
I think I am the only one who is NOT successful after doing the fix. I am still figuring out which step went wrong. I suspect it is the grounding.
 

DWB

Well-known member
Feb 26, 2005
62
0
Bellingham, WA
yuenie said:
I think I am the only one who is NOT successful after doing the fix. I am still figuring out which step went wrong. I suspect it is the grounding.
Did you pull the fault codes from the SLABS computer? If so- what were they? If not --you need to do so and make sure this is the correct repair for you. This fix is for "Shuttle Valve Electrical Failure." It won't work for say a bad wheel sensor or other fault in the ABS system. Also, did you have a hard or soft fault code? Hard- the amigos are on all the time. Soft- they come and go intermittently. If the fault is "hard" - you may need to have the SLABS reset with a code reader to get them to go off.

I followed the write-up precisely, right down to using the same type of trailer wire connector, soldering all splices and using the same ground point. So far so good- no amigos.
 

GoodJava

Well-known member
Mar 24, 2006
56
0
San Marcos CA
+1. I used the exact same trailer wire connector, soldered and shrink tubing, etc...

This fix should correct the 11.4 Electrical fault only.
 

yuenie

Member
Jul 29, 2008
20
0
DWB said:
Did you pull the fault codes from the SLABS computer? If so- what were they? If not --you need to do so and make sure this is the correct repair for you. This fix is for "Shuttle Valve Electrical Failure." It won't work for .....
Yes, the code is 114 Shuttle Valve Electrical Failure. I just had my ABS Amigo 2 days ago. The amigo is a HARD one. The 3 annoying guys are ALWAYS there, not intermittently.

I also bought the same trailer connector. The only difference is I haven't soldered but just tied up the copper wires because my soldering thing is not working. Another thing I suspect is the ground. I clipped it to the metal holder of the steering reservoir instead of the bolt in the write-up. It's because the bolt head is rusted and rounded.

Is there any electrical test I can perform WITHOUT TAKING OUT THE SHUTTLE VALVE again? It is a pain of removing the 3 screws. :)