Disco 2 ABS fault code guidance needed

I have 2 fault codes on the ABS that i cant clear and need some guidance on.

1) Front right outlet valve short to ground
2)Shuttle valve switch electrical failure

I haven't yet looked at the front right issue, but would it be correct to start to look around the ABS wheel sensor on the hub as the usually culprit. Or will it be within the ABS module?

regards the shuttle Valve fault, I've removed the ABS switches and carried out the mod (option B) i measured the switch resistance and all good. Tried to clear the faults a few items and they are hard on (oh -er).

Any advise please?

It seems that there is a wiring issue between the ECU and modulatior or a problem within the modulator cos both faults are related to the modulator side, the outlet valve is within it...if you are handy with electrical measurements and you have RAVE(for connector views) and a multimeter i can tell you where to measure to rule out things

here is the modulator's inner scheme, the SVS option B shown with purple , OV = outlet valve, the one which goes to pin 13 is the front right one and you'll have to measure resiostance on the modulator's plug that pin agaisnt earth and if it's open circuit it means the harness is chaffed somewhere and that affects the SVS input too(quite likely scenario)

im handy with electrical circuits and have multimeter but do not have RAVE

download disc 1 from here http://www.myrangerover.co.uk/rave-workshop-manual/ then when you have it see Electrical library - Connector views - C0501, unplug it and measure resistance on the modulator where pin 13 fits and ground, it shuld be open circuit, if it's closed the modulator must be changed ... if you measure across pin 6 and ground you must get the SVS released(3Kohm) and both switches pushed(1Kohm) resistances with released and depressed brake pedal...if here all the resistances are OK the problem is within the harness or a possible but more uncommon scenario is ECU fault

wow thanks, a wealth of knowledge! Am i correct to assume the connector detail is as looking on the end of the wired plug, so reversed on the modulator. If so pin 13 is o/c . however pin 6 to grd is 0 ohm pedal pressed or released

Just looked again at the Option B mod I carried out and it looks like I wired the new wire from the switches to pin 13 on the connector not pin 9. I've remade the connection to pin 9, cleared the faults and the Front right outlet valve short to ground has gone. Which seems to make sense as the resistance from this wire to grd is 0 ohms. So one fault cleared even though it was an own goal

When I bench tested the switches I got the correct resistances, however now refitted with the pedal pressed or released it's zero ohms between grd and the point where the purple wire meets the existing wire on your first diagram, any ideas re this? what operates the switches?Surely the lowest this should be is 1k ohm?

One final point i didn't cut the existing yellow green wire, just spliced the new wire in place so its running in parallel with the exist pin connections, do you think this could effect it?

we wrote at the same time ....yes cut the yellow/green wire toward the modulator

The connector view is from the pins/cavities side of it ... i missed something in my first post on the OV/IV circuits it's not supposed to be completely open circuit cos there is the solenoid's resistance around 5.5 Ohms i dont remember exactly how much, as long as pin 13 is the same with all the other OVs to pins 1, 10 and 5 agains ground they are OK measure them all against pin 8 too which is the referrence ground and if they are all the same around 5.5 that short to ground fault code comes from the harness or ECU... also for SVS i said pin 6 by mistake(i'm a bit tired) but it's pin 9 where the yellow/green wire goes, there you shold get those 3K and 1K readings... , now disconnct the battery, remove the glovebox, unplug C0506 form the SLABS and mneasure resistance across ground and pin 4(this is the circuit to pin 13 modulator FROV) then across 4 and 3 if you get resistance here there's a wiring issue on that loom

i'm after two night shifts and didnt sleep much so compare the diagram with my statements cos i might mix things a bit

OFF COURSE... my bad again...you should get those 3K and 1K resistances on the wire which is connected from the SVS to the yellow green wire not on the modulator cos with option B the modulator is bypassed and out of circuit and if the OV fault is gone let the SLABS alone

ok thanks, thought you meant pin 9 not 6 all pins 1,5,10 and 13 are now 5.5 ohms and the ground fault cleared. Think the issue is around the switches as between the option B (new) wire and grd is zero ohms, brake pedal pressed or released. Think i need to get the switched out again . will have to be tomorrow now as dark and cold here

ok check tomorrow if the other wire from the swithces is well connected to ground and if it is you should get 3K and 1K with pedal released/depressed across the two new wires coming out from the SVS and if you dont you didnt connnect something well there or the switch pack failed, better wire in a new one cos it's not expensive

OK, thanks for now, you're given me some really good pointers

When I added the wiring mod I did not remove the existing connections, think having it in parallel was no problem, however appears I had crossed the wires hence the zero ohms. Mod removed and all fine. No fault codes or warning lights Yahoo I think the initial problem may have just been a dirty contact on the SVS into the modulator.

Once again thanks for advise

You might be lucky and your fault was just a mucky connection. More likely is that one of the pins on the two way connector to the SVS switch plate has an intermittent soldered joint inside the ABS modulator.
Be prepared to redo the modification "Option B" in the near future, and next time, make sure that you cut the green/yellow wire where @sierrafery has indicated in his diagram.

Yes I did think that. The wires are still there just disconnected, so if it happens again I'l cut the wire and reconnect the mod

The OV fault was coincidental, maybe bad contact in the plug cos it has nothing to do with the SVS... anyway i'm glad it's sorted

the OV was caused be me doing the mod wrong and mistakenly earthing pin 13 I

aaaaaha...i missed that