Thread: D2 CDL and/or Traction Control?

Originally Posted by Fluids

No, I didn't ... it was my first attempt at some light "what can we do" driving ... been here, done it all in my former two SIII's (74 shorty softop & 77 longy 5door wagon). Driving them on the same dunes required a completley different approach (floor it!) with their 7.5x16LT tyres ... and I was younger and braver ... (got the SIII wagon air borne off the back of a sand dune ... ouch!) so still feeling my way with the new D2a ... my 1st auto ever as well !! I like it

I will give it a try using manual mode .... was the 1st time I've aired down in the disco ... the beach and dunes have been hard enough for road pressures (32/36) and I'm running Cooper ST ... will try 15psi (with driver & 5 passengers ok ?)

Thanks

I haven't tried it on really long dunes but certainly in long stretches of really soft sand having the car in manual and low 2nd or 3rd worked really well. The theory I was given is it allows you to accelerate without changing down and so you don't lose momentum.

I've aired right down with the disco fully loaded - the only thing is I didn't go to 15 psi on the gauge, I allowed for the fact we had been running at higher pressures and warm tyres - so if I started the day at 25psi, pressure had probably gone up to 30psi so I went down to 20, which with cool tyres would be 15psi, if that makes any sense at all

cheers, Andy

Originally Posted by Ferret

....The reason it is different is because on the D2 the cdl was never supposed to be engaged. The D2 computer is programmed to disable traction control when it senses the cdl engaged but it can be tricked to ignore the cdl and leave traction control active.....
.

Hi Ferret, could you restate this please, the above is contradictory.
Are you saying this for the non CDL D2? I'm not clear.

Your maybe not familiar with the D2 setups.

Early model D2s had the cdl internals fitted in the transfer case but no means of activating it from within the cabin. This was because Landrover never intended the cdl to be activated by the driver. It was thought traction control was all that was needed.

In fact in later model D2's Landrover completely removed all internal components of the cdl from the transfer case because of this belief.

So for the early model D2 people found they could engage the cdl by crawling under the vehicle and manually activating the cdl by turning the cdl adaptor spigot with a spanner. When this happened the engine computer would get 'confused' and disable all ABS functions (traction control, ABS breaks, Hill Descent) because it was just not supposed to happen.

People later found they could 'trick' the computer by turning the engine on first, then engage the cdl. The computer's check on whether cdl was engaged or not only occurred once and only before starting the engine.

So whether traction control is on or off depends on the sequence used to engage the cdl.

1. engage cdl then start engine - the computer will disable traction control (and ABS & HDC)
2. start engine then engage cdl - the computer will leave traction control enabled (and ABS & HDC)

So, like I said, you don't really turn traction control 'on or off' as such, you trick the computer into 'enabling it or disabling it'.

My understanding is that you can't do this on the D2a because it was always intended the cdl would be operated from within the cabin so the computer is not so easily tricked into enabling or disabling traction control. But like I said I don't own a D2a so maybe others can confirm this is the case.