richardlennard

Update. Replaced N/S ABS sensor, hit RH sensor lightly to bed in!, Hawkeye now registering speeds on all 4 wheels. So all 4 wheels read exactly what they should do, lights all out for 100 yards, then on and bells. Read DTCs yet again, RH sensor "Air gap too large". So new sensor for RHS as well, hopefully this will finally sort it. It has to be said, unless very familiar with this type of truck, it is virtually impossible to repair unless you have a decent diagnostic equipment. It most certainly isnt progress, the whole 3 amigo thing is disgraceful. What on earth would you do in the mountains, desert etc. Unless you had a whole load of gear with you they are virtually irreparable. Unlike my old Patrol - absolutely indestructible. The Discovery is nice to drive, but it is just a "****ing horse box tow truck", it isnt a work vehicle. Ive spent so much time on this truck it will have to do a few years, I hope to god the experience gets better!

3 amigos now out after left for 1/2hr. I dont know if relevant but if you try to pull away the TC light only will come on at about 2mph with the corresponding noises from the front. If you gently touch the brakes and keep them lightly pressed, the light will stay out whilst still driving indefinitely. Also the TC light only comes on when wheels are being driven. Press the clutch and freewheel and the TC light stays off. Surely if there is a speed imbalance or a registered difference, for whatever reason, then the TC light should remain lit?

Todays efforts so far. Ive read through numerous "ABS" related faults on forums. Hawkeye checks earths etc, all passed, but I earthed ecu small wire, direct earth to main engine block - no difference. Worked from Wabco ecu to each wheel, all gave 1000ohm resistance - so OK. Checked all connections, cleaned earths wherever, but all looked good anyway. Contact cleaned Wabco sensor jack plug. Live test - no speed from back wheels, but front OK 3 amigos all cleared each time successfully. Removed rear sensors and cleaned grease from ends (didnt think it would make a difference, but did!). Back wheels now register speed immediately when spun manually - so OK Next live test - no speed from front wheels! Aaaagh! Checked all connections - all appear OK. Front axle in the air, spun front wheels manually - nothing registered on Hawkeye. Drive front axle, on axle stands. Speed kicks in with a value of 2 -3 mph, whilst wheels are doing 40 -50 mph, then speed rapidly catches upto match. Out on the road the front axle wont register speed at all but rear is OK. 3 amigos wont clear now, even after clearing DTCs 3 times. Hawkeye says all faults are cleared each and every time. Im thinking the Wabco ABS ecu is playing up? I think all the right signals are going everywhere but that the speed side of it is saying there is an imbalance front to rear, whilst in reality there isnt? Anyone had this problem with the ecu?

I checked all brake calipers, in case one brake hanging on relative to the other. They were in a poor state, rear all cleaned up ok, but front seals u/s and 2 pistons poor. Front calipers replaced, all bled out ok. When trying to pull away, upto about 2mph, all lights stay off / behave exactly as they should. Anything above just moving, the TC light comes on and, not certain, but N/S/F brake starts to apply. Correct noises from ABS. If you just touch the brake and keep it just on, then the TC light will go out, not come on and vehicle drives exactly as it should. Any ideas what I should check next? Checked with Hawkeye again, says no faults and all corners seem to show correct values. Thanks in anticipation!!!!!! I sold my 4.2 SWB Patrol for this vehicle - Me thinks, Bad Idea.

Next stage! Connected new hub ABS plug in. Ran Hawkeye - no difference. Live readings for ABS: LF, LR, RR all inlet 0-0.07v, outlet 2.25v. LR, the hub that I changed over for S/H, Inlet 0.07v and outlet 0.14v. Is this higher voltage likely to affect the ABS?

Yes did that. All values seemed similar. Thats what I thought was going on, an imbalance in the signal returned to the ECU. I changed one of the front hubs for a s/h unit. Hawkeye gave same readings as for the other sensors, so I thought all should be OK. Hawkeye - all faults cleared. But trouble started at this point. Have retested all readings, all appear OK. Im going to change this hub for a new unit, so will have to see what happens.

No, Im familiar with how it all works. If you have all 4 wheels off the ground, then it will drive as it wants, ie all the wheels go at whatever speed they are happy at. Put it on the ground with some resistance and then by 3mph, everytime, then TC starts cutting in, light comes on. If you didnt know any different you would think the brakes are taking it in turns to bind. Hawkeye live says each wheel is behaving as it should and when tested says "No faults". I suspect one of the ABS sensors isnt behaving quite as it should, throwing everything into confusion. Ive ordered a decent new front hub, this was the one that I changed for a S/H hub. As I said Hawkeye was happy with it, but got to start somewhere.

2001 TD5. I started with all 3 lights on. Hawkeye removed all, no faults. Checked each wheel for ABS, all constant and correct. I replaced O/S/F hub, S/H, but prior to clearing lights. When I try to pull away the TC light will almost immediately come on, corresponding brake juddering. If I press the brakes lightly then I can pull away, the TC light stays out. As soon as I release the brake pedal then the light comes on. I disconnected the front ABS wires, obviously the 3 lights came back on, but I could drive normally. Reconnected them and cleared the fault lights, the problem returned. I understand that by disconnecting the wires the TC is effectively disconnected. Recently I changed the gearbox, S/H. The old box had the diff lock intact but no lever etc, the new does not. With the "new" box I have front wheel drive only, when extra drive is required, ie front wheels spin and nothing from the rear. I suspect this is also tied up with the TC system of 4 wheel drive? Please can someone help!!!