Thread: Three Amigos - Fault Diagnosis

Hi Elliot,

I had a very similar fault.

I replaced the SVS put it all back together and then had an intermittent SVS power failure.

So I pulled the SVS out again and did the 'option "b'' ' on it.

Not a problem since. It is simple and I feel that you may as well do both while you have it out, to future proof it from further problems.

The tutorial can be found in The Good Oil section.
It is easy to follow and do.


Regards
Will.

Hi Will,

I am a bit confused about the Option b modification.

I have looked through countless posts but am having trouble getting a clear idea of what to do. Does this involve just putting in the LR shuttle valve fix kit? Or what is the option b part?

Sorry to ask these basic questions I am just having trouble navigating all of the information about this issue.

Elliot,

The option b mod is a separate thing to replacing the SVS.

However to do the option b, you have to remove the SVS.
As such, it would be easier to do the mod, whilst replacing the SVS.

Will

The step by step pictorial instructions were able to be found on the site -
ABS Mod - LANDROVER CLUB V.1.

Or search Good Oil on this forum.

With an intermittent 3 amigos - check the harness connection behind the glove box. Give the connection a push together.

An overload glove box (ie full of crap) can place pressure on this connection and cause the fault.

This is just one of the many causes, but easy to check & then discount ....

Good luck !

Pete

This SVS issue was explained many ways but never this way, i edited the internal diagram of the ABS modulator concentrating on the SVS module(SWO500040), i marked where IMO the problems usually are with orange but in case of oil ingress to the switches those resistances(with red) will be affected and the fault is the same, with purple are the external wires of mod option B, blue is the switch pack(SWO500030), there are two important notes on the original scheme:
* TOTAL RESISTANCE INCLUDING CONTACT AND CRIMP RESISTANCE: R<0.017 OHMS for the connection which gives the main earth(that big earth connector below the multiplug
**TOTAL RESISTANCE INCLUDING CONTACT AND CRIMP RESISTANCE: R<0.04 OHMS on the refference earth(ground) circuit from SLABS to pin 8 of multiplug



so there will be SVS related fault code if the resistances of the switch pack are out of range(which from MY experience is rare) and if one or both of those two earth circuit resistances are out of that "tight" range(thats the most common IMO), so taking with external wires the switch pack in series between earth and the SLABS ECU's SVS input the internal circuit of the modulator is bypassed and the only case in which the 3 amigos will come on again is if the switches will be ruined by fluid ingress ... that's why i'm saying that the brake fluid ingress is not the most common issue cos many of those who made option B didnt replace the valve seals, some of them nor the switch pack just made the wiring mod and they haven't seen the 3 amigos generated by SVS fault code again

also for those who made me idiot a while ago i just want to thrust out my hand and tell without creating another unfriendly debate that this scheme proves that the SVS assy/module doesnt "modulate" anything nor working on a "huge range of resistances" it just simply gives the breakes on/off signal to the ECU based on the closed or opened status of the switches which are actuated by the pressure generated when the pedal is depressed/released... period, in the whole (BIG)modulator's operation description the SVS's are not even mentioned only once briefly cos modulation is achieved exclusively by the IV(inlet valves), OV(outlet valves) and return pump which are commanded by the ECU based on the various wheel speed sensor's inputs

if i'm wrong and somebody can correct me with respect it's OK if not i'm not gonna answer to any agression, i just want to help with this explanation cos i've read the whole WABCO document at least 10 times to reach this conclusion and i wanted to share the info that's all

I went and purchased a new SVS recently and put aside a day to change it over. After much reading I decided I would do the option b mod as well. I ended up putting the old SVS back in after the mod as it seemed in decent condition and resistance tests showed it to be identical to the new one. I now have a spare SVS in case of emergency, and haven't seen any dirty amigos since!

Sent from my HTC_0P6B using AULRO mobile app

Hi all,

Thank you for the wealth of information you are providing me.
I think what I will do is order a new SVS and do the option b mod.
From what I understand from the diagram above, does this mean by passing certain components (a switch) and just wiring the SVS straight to the slabs ECU?

I cannot access the fabled option b mod explanation on the Land rover club it keeps saying the website domain is up for sale. I will keep looking though. If someone saved a copy that would be awesome.

For the SVS switch would you recommend going to get a genuine LR part? I was going to go with this http://www.ebay.com.au/itm/Land-Rove...item2ed78a3949

Thank you for your help