[david013]

My 2004 is getting the 3 Amigos very intermittently. It will sometime occur while driving or also while setting in park after a few minutes w/o pushing on the breaks.

I pulled the codes and it has a 4114, and 4134. I'm planing to replace the ABS Modulator Shuttle Valve Switch (part # SWO500040), but I want to make sure that I'm replacing the cause and not a symptom as 4134 is a fault for the Motor Speed Input.

Does anyone have experience with 4114 causing the 4134 or the other way around. Also is it typical for it to be very intermittent or is that more indicative of a bad wire / ground.

 

[david013]

Update - I replaced the ABS Modulator Shuttle Valve Switch and got the 3 amigo's after about 5 miles of driving. The contacts on the old one still looked good without any noticeable corrosion in the unit .

 

[sierrafery]

Firdst of all what kind of code reader did you use?, you need dedicated D2 equipment for proper diagniostic of the ABS ECU cos it's not OBD2 compliant, a dedicated tester would have gave you clear description of the codes, those figures are irrelevant without the description cos each tester has different numbering... come back with the proper fault code descriptions and i'll tell you more

 

[david013]

Thanks Sierrafery, I'm using my Lynx Diagnostic Tool, which should cover everything for my Discovery. I ran the actuator test for the ABS Modulator Shuttle Valve Switch and it passed. If you're familiar with the tool is there an additional test that I can do for the motor speed input. I did replace the cps about an month ago which resolved an inconsistent starting issue. So its possible that the motor speed input could be an old code from that if thats what the ABS system uses as an input but I'm not sure.

I cleared all the codes and will rescan this evening to pull just the ones from the latest three amigos siting.

 

[sierrafery]

Yes, engine speed input missing could have been logged due to the CPS, Lynx is good, read the codea again after the 3 amigos will show up then post the detailed code description

 

[gurunutkins]

most of the problems with the shuttle valve are not the shuttle valve per se but the crappy connections on that long piece of circuit board that the wires clip into. There are various write ups and bypasses which work very well and I would suggest you look at doing one of those with the new shuttle valve switch. I'll dig around in my files and see if I can find the process. Some of the pics will be missing as I had to use the way back machine to pull up some of the web sites. It used to have a link in the stickys at the top of the forum but I think its now dead
cheers
Barri

 

[sierrafery]

David repolaced the whole SVS assy SWO500040 which includes the bad contacts not just the cheap switch pack(SWO500030) which comes connected directly to earth and the input to ECU with the wiring mod so as long as there's no problem somewhere between the modulator's plug and ECU or bad earth the SVS fault is fixed with the new unit

 

[david013]

Thank you for all the replies, I scanned it when I got home this evening and the specific details from the Lynx tool is 4114 Shutter Valve Switch Failure Electronically Supervision - HISTORICAL.

Also - Sierrafery it looks like I mistyped the pn earlier, I only replaced the switches SWO500030, although I have the full SWO500040 in another discovery 2 that I'm rebuilding in my garage that I could swap.

 

[sierrafery]

Ok, if you replaced only the switch pack then that's what you should do: Disco ABS Fault

 

[sierrafery]

Here's the "graphic" explanation too:
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(these are within the module) 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), that so called "repair kit"(SWO500030) will rarely fix thing on it's own 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...i hope it makes sense

 

[Redrover NC]

Read the sticky at the top of this forum - ABS Modulator Fix (NO more SVS fault), then do Option B. It's at most a $5 fix.

It's well known that in many, many (most?) cases where the 114-Shuttle Valve Switch fault is logged the problem is not the switches themselves but the circuitry inside the modulator into which the switch pack is plugged.

I'm sorry you spent money on the shuttle valve switches before testing them as the sticky describes. You don't actually even need the two-wire trailer wiring plug to do the bypass. The bypass wiring can be installed directly to the yellow/green wire and to a ground.

I did the Option B bypass five years ago and have been AMIGO FREE since then.

 

[david013]

Thank you all for your support. I was able to pick up the complete SWO500040 unit for $75, swapped it out and flushed the break fluid to bleed while I was at it and the issue is resolved.