Thread: D4 Cruise Control

I haven't seen a CCF setting to allow 1 kph increments. If I catch a vehicle that's travelling slightly slower I'll increase my speed by 4kph until sufficiently past them then settle back to the speed limit rather than try to travel at their speed.

My CCF settings for my tyre size is set correctly (245/70-17) and the speedo algorithm selected is the one closest to no adjustment (IIRC 0%+2 kph) rather than the greatest adjustment (IIRC 5%+2 kph) previously. On level terrain with my CC set at 100 the speedo shows 100 and the GPS mostly shows 100 but sometimes 99. However my tyres when new were listed as 30.8" dia by Tirerack whereas the size has a nominal dia of 30.5", which probably accounts for my speedo not being 2kph optomistic. I'm happy doing 99/100 in a 100 zone with the speedo showing 100 or 109/110 in a 110 zone with the speedo showing 110 with CC set at 100 or 110 accordingly.

If changing CCF specs for non-standard tyre diameter then consideration might be given to correcting the CCF setting for the odometer. Faultmate has 2 tyre rolling diameter fields which I've found to be used to set the odometer - the Most Significant (1st) Byte and Least Significant Byte (2nd) such that when each is converted to hex to make a word of the rolling diameter then converted back to decimal, the number is the loaded rolling diameter in mm. I added 10 (mm) to the LSB value to account for my tyres' slightly greater radius than standard and the odometer has since agreed on several occasions with the freeway 5 km odometer checks whilst travelling in the left lane.

Watched everything very carefully on the Eastern Fwy & Eastlink today - all the way to Frankston.

Set at 104 kph and even on slight declines off bridges got 107 - 3 over is enough for a ticket. Dropped as low as 98 before regaining to 100 up the long incline under the Monash Fwy. Rediculous as cars catch you rapidly.

Set at 80 in the tunnel(quite a long reasonable downhill), not one gear dropped down at all, and applied the brakes as it was heading past 95 just a few hundred metres in.

The instantaneous fuel usage was at 0.0 on each down hill.

I tried gears myself to stop from exceeding 104kph. 4th was needed, 5th still allowed increased speed. 4th wasn't too harsh/high revving or noisy at 104.

Regards,

Les.

Originally Posted by outasight

Set at 80 in the tunnel(quite a long reasonable downhill), not one gear dropped down at all, and applied the brakes as it was heading past 95 just a few hundred metres in.

Mine drops whilst CC is not in use prior to touching the brakes with speed around 115 each time. Dropping to 5th didn't slow the vehicle and left me wondering if the change-down was to get more engine revs for more brake vacuum or for more engine braking.

I hate the CC on our D4, it will not sit at the speed you set it too, if I set it to 106kph (speedo is 6kph out) it then drops to 102, 103, it starts to increase and it will sit at 105 for ages, then go to 106 and on to , 107, 108, 109 then back to 103, 104, then 108, all this on a relatively flat road, it will eventually sit on 106 but only for a second then it's all over the place again

Baz.

Seems like everyone has the same problem.
Come on Landrover.........surely you have a patch for this??????

BTW: I have all the latest updates and my cruise does the same.

Cheers, Craig

Originally Posted by Disco4SE

Come on Landrover.........surely you have a patch for this??????

I'm not holding my breath for a fix as it took the whole D3 model run and into the D4s before LR changed CC code to totally cut fuel on overrun, and probably only because every D4 driver could see that fuel was still being used by looking at the instantaneous fuel consumption display.

Originally Posted by Graeme

I'm not holding my breath for a fix as it took the whole D3 model run and into the D4s before LR changed CC code to totally cut fuel on overrun, and probably only because every D4 driver could see that fuel was still being used by looking at the instantaneous fuel consumption display.

I bet fuel use is exactly the same, just the display is now kidding you that the engine's not using fuel! Just like the classic temp gauge adjustment that Holden pulled to stop Kingswood owners worrying!

I think while the CC is tedious under the discussed conditions, its a sensitivity compromise that makes it surge much less on undulating secondary roads, and therefore usable in a much wider range of situations...

Originally Posted by Stuart02

I bet fuel use is exactly the same, just the display is now kidding you that the engine's not using fuel!

Definitely not! Previously on downhill overruns the vehicle would race away yet now does not reach anything like the previous speeds on the same freeway hills. It now behaves the same as when CC was cancelled prior to the s/w update.