So after buying a hawkeye I find the shuttle valve switch to be at fault (code 4114, a.k.a 11.4, a.k.a shuttle valve switch electrical fault) - which is good, at least compared to the cost of wheel hub replacement!

My plan was to try the 'option B' fix of soldering the wires directly to ground/yellow-green wire. It seems like there is little point buying the 40 quid replacement SVS only to find I then need to resolder it anyway.

Does this sounds reasonable? Anyone else done it this way?
Also, any tips on the actual procedure? Not really done anything like this before so don't want to make stupid mistakes on the basic mechanics stuff. E.g. do I need to copper grease or loctite the screws when I refit them? Does exact torque matter for these screws or is it OK to guess it? How best to loosen stuck screws without rounding corners etc? Thanks!

There are two main reasons why you might get the SVS electrical fault, first it could be the fault often seen which can be sorted out by incorporating the option 'B' mod, the second reason might be that the SVS switch plate is actually faulty. There are three 1k resistors on the plate, an ohmmeter across the two wires should show 3 k with no switches pressed, 2k with either switch pressed and 1k with both switches pressed. Check this post by sierrafery for a diagram.

Since you're going to have to remove the switch plate either way, it does make sense to replace it and incorporate the mod into the new plate, although it would appear that the experience of the forum seems to indicate that replacement isn't always necessary.

The plate is located underneath the ABS modulator; there are three rubber anti-vibration mounts holding it. If you're careful and you remove the three clips holding the brake pipes below the ABS unit then with care you can lift it away giving you just enough room to get an allen key into the bolts, there are three of those too. Rounding the hex sockets in the bolts shouldn't be a problem if you have a properly fitting allen key. Don't forget to remove the plugs before lifting the unit. I found it helpful to have an assistant to hold the unit while I removed the SVS plate.

Replacing the SVS plate is a direct opposite of removal. There is no real need to torque the bolts up, just do them up with your allen key, you can put thread lock compond on them if you wish. I tried to torque the one I did with a small low torque wrench, but 4Nm is stupidly small and difficult to achieve unless you have the unit out and on the work bench.

I recently had the SVS replaced on my Discovery 2 by a garage as the three amigos kept coming on, and the SVS failure code came up. All seemed ok for a few weeks, then the lights came on again. Now armed with a Nanocom, I read the fault - SVS again 23 times, and cleared. Again, all ok until yesterday, when lights came on again and fault read SVS another 23 times. Have cleared but assume this will keep happening. Could the SVS that was fitted be faulty, or is it more likely that there is another issue? Read somewhere about the ABS module repair kit SW0500040 - costing about £400! Assume this is not required to sort the issue?!

archwayanimal said:

I recently had the SVS replaced on my Discovery 2 by a garage as the three amigos kept coming on, and the SVS failure code came up. All seemed ok for a few weeks, then the lights came on again. Now armed with a Nanocom, I read the fault - SVS again 23 times, and cleared. Again, all ok until yesterday, when lights came on again and fault read SVS another 23 times. Have cleared but assume this will keep happening. Could the SVS that was fitted be faulty, or is it more likely that there is another issue? Read somewhere about the ABS module repair kit SW0500040 - costing about £400! Assume this is not required to sort the issue?!

Click to expand...

Do the wiring modification.

+1^^^, only replacing the SVS switch pack is not enough, or do the wiring mod or go for the very expensive SVS assy...which might fail again the same way in 10 or so years, a good tutorial of the mod is here http://www.thed2boysclub.co.uk/viewtopic.php?f=15&t=18297 but you must be registered

There's also a useful write-up with the all important pictures (we like piccies) at:

Disco ABS Fault

IMO it's not the best way like in the link cos there's no reason to leave the modulator connected in parallel with the wiring mod so that setup is overcomplicated to no avail, also in the unlikely(but possible) case that there will be an internal short in the modulator's circuit i will disturb the wiring mod too and bring up the amigos

Well after 2 hours of attempting to remove the SVS I have admitted defeat - the centre hex screw just will not come out, and I've damaged the screw's head from trying.
The only way now will be to remove the whole ABS unit and get it on a bench so I can try and remove the screw without further damage.
The other two screws came out with some difficulty - the damn loctite is the problem!

When I disconnect the ABS modulator, will much fluid come out? Should I cover up the sockets on the modulator side? (If so, how?)

I presume I'll need to bleed the system after. I think I can use the Hawkeye for that. Do I have to remove the wheels etc and do a full bleed, or is there a shortcut given im not actually trying to drain the system at all?