Thread: 110 TD5 Traction control

mornington peninsula

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The TC will allow all wheels to spin at the same time, in fact that is exactly what it tries to achieve.
it will only apply brakes if it sences a differance in wheel RPM, If you spin one wheel at a higher RPM than the average of all wheels it will think that one wheel has broken traction and will apply the brake to that wheel, and it will do this to all wheels until all the wheels are spinning at the same time.
If you spin all wheels at the same speed it considers that all wheels are performing the same role,,,,,, If it would not allow all wheels to spin at the same time,,, There is no way you could drive straight and level down the highway.

I have a 2002 Extreme with traction control and front and rear ARB air lockers. I also have maxidrive axles. In my experience of relatively hard but slow crawling 4 wheeling, the traction control has not activated while the lockers are engaged. Not saying it couldn't, but it doesn't make sense that it would if the axles are locked and all wheels are turning at the same speed.

Regards, Barry.

Thing that gets me is the reliability of the TC and replacement cost of parts. Two grand a pop in this case and three times ! This is the best of new technology ? Can't justify that, rather disconnect the fuse, forget it ever had TC and stick with the lockers on their own.

There's probably some ETC's that work well and some that don't, but it's a bit like manual or automatic freewheeling hubs. Becoming more of a manual person myself as time goes by with these things, it's a reassurance to know when they're in they're in, when they're not they're not.

Just a clarification; the ETC logic applies only to both wheels on an axle. There is nothing to stop front/rear wheels spinning. With a CDL engaged that couldn't happen anyway.

With lockers in, ETC is not deactivated, but it cannot engage as the wheels on the axle must turn at the same rate. So it'll never kick in.

If you have a locker on one axle but not on the other, then you may get ETC assistance on the other axle.

[img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] If you read the technical literature for the TC, it describes that it will sence the RPM from each wheel(all four as indivaduals) whether it be front or rear, left or right it does not matter. The TC will average Referance the RPM of all four wheels and then apply brake pressure to any wheel that signals a higher RPM than the average. You can, in loose sand, end up spinning all four wheels and the TC thinks that the car is providing evan traction.
The system can't measure road speed, it can't measure torque at each wheel, it cant do anything but sence wheel RPM from its pulse sensors at each wheel and try and achieve equal RPM at each corner. :wink:

With further thought to the original problem,,, you might find that by locking both axle diffs and not locking the centre diff,, you may be confusing the TC by having exact RPM at both rear, and exact RPM at both front wheels but differant from front to rear. This may give an average PRM that cant be computed by applying brakes. I mean if the TC tries to apply front left brake it will effectivly brake both front wheels with the axle diff locked and alter the whole average which would prompt another brake etc etc. Not that this should matter. :?

If you lock both axles and the centre diff then the wheels wont spin at differant rates and the TC wont apply brakes. But more importantly the wheels will try to spin at the same RPM regardless of traction at each wheel,,,,, therefore if you do get 100% traction at one wheel while the other wheels are bopping around all over the place,, then you have one tiny little axle trying to haul 2.25 tonne

Perhaps you are just snappin axles like any four wheel drive(TC or not) will if you lock all its diffs and hammer it.