Technical Does my ELD Button Do Anything??

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Technical Does my ELD Button Do Anything??

Watching the Cross versus RR Defender video in another thread it occurs to me that the downhill setting only appears to apply the brakes as it seems to depend on the ABS function - or does it also change the engine setting to give more engine braking, which is otherwise a weakness?
 
Watching the Cross versus RR Defender video in another thread it occurs to me that the downhill setting only appears to apply the brakes as it seems to depend on the ABS function - or does it also change the engine setting to give more engine braking, which is otherwise a weakness?

No, it's just ABS doing it's thing. Descent Control in the Cross is automatic and requires nothing of the driver as it can apply the brakes under its own power using the ABS pump. In the normal 4x4 the driver would need to provide the pedal power, but gently to avoid over-working the ABS if it's particularly slippery. Other than that, the end results are the same.

In extreme conditions before the world of ABS, one could use Power Braking to descend a nasty slope if it was too slippery even for engine braking alone. Trick is to drive slowly down the slope on a positive throttle, controlling the speed with the brakes. Wheels could therefore not lock and you should have control to lift the required descent speed to the point where grip (and control) could be retained. Would still work today, if need be.
 
And another thing..... Looks like I may have answered my own question about just how much additional locking the ELD button does when pressed. I found a big gravel/mud bit of the station carpark yesterday and put the steering on full lock and drove dead slowly without any buttons pressed. Silence prevailed in terms of 4WD type noises and car turned easily.

Then I hit the ELD button and I could feel a gentle 'stiffening' of the steering and progress, nothing much, but enough to detect a change. In addition the sound changed and I could hear a very slight pulsing from the read diff - a low, subtle noise - nothing to write home about, but definitely there and obvious.

So I now remain convinced that despite what we might think, the ELD button doesn't actually lock the thing solid, but as has been said by HH and Goudrons, merely primes the diff to be ready to react quickly, should it be needed. The stiffening and light noise are evidence of that.

Either way, I still need snow to make this a proper, proven experiment!
 
That's probably unlikely Babbo.

There's little that can be altered to increase engine braking with a diesel engine.
They virtually inject no fuel when you take your foot off the pedal anyway and the air intake is controlled by the valves and not by a butterfly valve, there's nothing really to increase the pumping effect and slow the buggers down!

Again the TA has no butterfly, but it probably could alter the air intake to the cylinders to increase engine pumping with it's multiair system, but it would need to know when.

It would also need to do this cleanly and keep combustion temps within a reasonable range as in both cases, pumping and squeezing a lot of unused air will increase the combustion temps way beyond normal operating temps which also leads to profilic NOx production.
 
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