Traction control, Amigos and diagnosis of problem on Disco 2 TD5

[gregausit]

Hi All,

I am having a stab in the dark after reading how the systems work and peoples issues with the "Amigo's"

I am near Liverpool in NSW, have no Nanocom or diagnostic tools, not even sure of any local shops that may have them, anyways, can I get your opinion on my crude diagnosis of a problem.

I noticed first in the wet when I first got this vehicle, that it would wheelspin front wheels quite easily in the wet, some time after that when reading about the syetems on the vehicle, I concluded it should not do this, well not easily on wet tar or if it did, it should be promptly stopped by the systems ABS, anyway..

to test it out a bit more, I went to a private property with slopes, grass and some dirt tracks, seems that ABS works, however not sure if it operates correct on all wheels, but I can get it to operate.

then also on gras and dirt, gunned it a few times and as I thought, the front left wheel will spin madly and for as long as I keep the boot down, obviously it is not working well as a 4WD & confirmed that by not being able to climb a dry dirt track that I had been over in my last 4WD...a 1983 rodeo ute with 1.6ish 4cyl with zero guts :)

on spinning in the grass at a higer rate than on the road, I could hear some sort of clicking sound, not strong like the ABS when activated by hitting the brakes hard, but a rather odd sound, it is not there when the wheel is travelling down the road at any speed & only seemed to be there when there was excessive traction loss.

I am yet to get under the thing and check for a diff lock, but I am not confident as it is a 9/02 model, if it has that I probably would not care for the electronic system, I would prefer if it had a locker on the front diff like the old rodeo had !

If someone lends me a nanocom or I get one, would it tell you th eexact problem ?

My diagnosis so far would be that the sensor on the front left is no good or the cable has a problem, what do you reckon and say ?

PS how often is it just a cable or poor connections in the electrics ?

TIA

[mousie]

I've had the TD5 2000 model for many years now and I have found that with mine, when I occasionally get the 'squealing brake's from lots of dry dirt roads, the amigos come on and it is usually random which wheel. Just over 202K now. The squeel following by traction control kicking it is the combination I know will fault the system.

I use the nanocom to reset until next time. Yes, I have been right through the system and cannot fault sensors, connectors or the blame given for suspect cables and I can just about tell when it will fault from the level of dust exposed which is not often as it is in only very dusty to bull dust conditions.

I believe this has been discussed as well given I had all intentions of finding the fault but now just accept it.

[strangy]

Have a look here http://www.aulro.com/afvb/electronic-diagnostic-systems/101644-members-diagnostic-equipment-map.html

Also look in here http://www.aulro.com/afvb/good-oil/34321-electronic-driver-aids-including-3-amigoes.html .

You are correct, in that anything else is just a stab in the dark without diagnostics.

[OffTrack]

If someone lends me a nanocom or I get one, would it tell you th eexact problem ?

My diagnosis so far would be that the sensor on the front left is no good or the cable has a problem, what do you reckon and say ?


I don't think the diagnosis is necessarily correct.

The ETC is completely disabled for all three amigo's faults except a failed brake lamp relay so you are just identifying which wheel has no traction not which sensor has failed.

If you want to try identifying where the fault lies without diagnostics you can use the table of resistances on page 70-24 of RAVE (Last page of the Brakes: Description and Operation section) as a reference to measure resistances of the sensors, shuttle valve switch, and relay coils. If you have the sensors with the plug near the wheel arch, you can measure at both the plug and at the ECU to check for a wiring fault.

I'd suggest rechecking when the vehicle was built. 2003MY production began at the end of 04/2002 and all australian delivery 03 and 04MY D2's came with the diff lock lever and internals. There is a small plate that is riveted to engine bay between the passenger headlight and the airbox which will tell you the month and year the vehicle was built. The compliance plate date can be anything from one to twelve months later than the build date so is a red herring.

There is a sticky in the D2 forum with a bit of information about VIN's build dates etc.

http://www.aulro.com/afvb/discovery-2/155178-model-years-build-dates-vins.html

The Nanocom will read any faults that the ABS ECU has logged. The faults identify a problem associated with a component. You still have to confirm what is causing the issue. A sensor fault for example can have multiple causes related to the sensor and sensor wiring. The fault codes basically narrow down the fault to a specific circuit and the type of error condition logged (short to 12V, short to ground, or open circuit for example) , rather than giving you the exact problem.

cheers
Paul

[OffTrack]

Attached is a Wabco tech note which covers checking the sensors. It's aimed at warranty claims but is useful for i.d.ing a dud sensor.

The correct ABS sensor resistance given in RAVE is 950-1100Ω

cheers
Paul