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Auto and Cruise Control and towing.
Posted: 10 May 2013 19:24
by NISMOnator
Hi Almal,
The Patrol is my first Auto vehicle. I used the cruise contol for the first time today to test. The road consists of a lot of up and downhills. When on straight road the vehicle goes like normal keeping speed and obviously downhill also fine. When hitting an incline the vehicle does not really keep steady. It keeps speed as incline becomes steeper the vehicle seems to suddenly figure out it needs to hall ass to keep that speed. So it suddenly down gears two gears floors it to just over 4000 revs to get back to speed gears back and sort off tries again. Is this normal? Is it better in manual mode? Triptronic with cruise on? Please note I am not towing anything when this occured today!
I have a manual Honda and use cruise control on that vehicle a lot and is very smooth and keeps speed steady. I can only blame the Auto I guess?
Then my next question. When towing boat or trailer is it advisable to use cruise control?
When towing should you rather use the manual mode to do so? Does the 4.8 have issues when towing in 5 gear? Read on this forum on various occasions that the 5 gear stripps on 4.5 due to towing in it.
Please correct me if Iam wrong?
Thank you
Re: Auto and Cruise Control and towing.
Posted: 10 May 2013 21:35
by Jorrie
Jacques, talk to Chris Skinner on this forum. He seems to have a lot of experience in this field.
Re: Auto and Cruise Control and towing.
Posted: 13 May 2013 10:46
by Chris Skinner
Hi Jacques - I have experienced same problem with the speed control - the way the control system is set up is not ideal.
The system is designed to react when the speed can not be maintained in the current gear - problem is that it reacts too late and then has to drop a gear or two and apply full power to get back to the selected speed, but when it gets there, it is accelerating so fast that it overshoots the mark and decreases power too much so the speed then drops again and the cycle repeats itself - someone described it as a sling shot effect. I am not sure if anything can be done about programming the computer with a more responsive control algorith.
Being in manual mode will definatelys help but the problem with the Patrol is that you can not select speedcruise while in manual. There is a very simple mod which can be done to overcome this - I did this and now its easy, if in auto and speedcontrol mode, and i see a hill where the speed will drop, all i do is tap the gear lever over to manual and back to 4th before the speed starts dropping and then climb the hill in 4th.
Generally I do not tow in speedcruise mode as my boat is extremely heavy and one has better control with the foot on the accelerator.
When towing i leave the setting in manual 4th - i have learned my lesson of towing in 5th!

Re: Auto and Cruise Control and towing.
Posted: 13 May 2013 11:41
by NISMOnator
Thank you Chris!
My boat is very light though? Would that still be an issue towing in 5th?
I guess doing it is 4th also doesnt hlep with fuel consumption as you can not use overdrive?
Thanks again!

Re: Auto and Cruise Control and towing.
Posted: 13 May 2013 15:33
by Chris Skinner
I really do not think you will see any difference in fuel consumption when towing whether in 4th or 5th, at the speeds 90-110kms/h. Actually at these speeds I am almost always throttle almost to the floor to overcome the wind resistance anyway - and in 4th you are closer to optimal torque so better efficiency theoretically in my view.
I was towing a trailer filled with hunting spoils (probably 1,5 tons) when I blew a 5th gear on my 4.5 patrol - on the long straight road from Warmbaths to Pta. I wont make the same mistake again. The 5th gear is very small and not well lubricated (in the manual box anyway!), as told to me by the specialists that repaired it. Eventually it heats up to the point of self destruction when under longer and harder than normal driving load.
Re: Auto and Cruise Control and towing.
Posted: 13 May 2013 17:21
by NISMOnator
Thanks!
Ok now that is what I call a boat!!!! Maybe mine next to that will be seen as a canoe with an engine!!!

Re: Auto and Cruise Control and towing.
Posted: 13 May 2013 21:09
by Louis Hay
I have similar issues with my Patrol. But it's not the auto by itself, my wife's auto Vito 3.0 diesel tows like a dream, no hunting for gears, constant speed, so I have have to agree that it is the programming of the Patrol that is the issue.
Re: Auto and Cruise Control and towing.
Posted: 13 May 2013 21:13
by Chris Skinner
Hi Louis, the diesel probably has enough torque to maintain the speed setting when towing something light to medium in size so does not need to kick down a gear.
Re: Auto and Cruise Control and towing.
Posted: 15 May 2013 15:10
by dieselfan
The Disco 3 does the exact same, basically the CC wakes up too late then is too aggressive.
The Pathfinder has the CC sorted out both the auto and manual behave very very well on CC. Usually only -2 +2km/h. The disco can drop to 108 from 120 then drop a gear and surge to 135. Maybe the CC can be remapped on the Patrol? My dad had an aftermarket CC fitted to his 4.2TD and it needed calibration.
Re: Auto and Cruise Control and towing.
Posted: 22 May 2013 09:00
by Cobus Terblanche
Hi guys
I complaint about the same issue in a previous thread. Chris's suggestion of towing in manual works perfecly and the fuel consumption is also much better. The problem I face is that I sometimes find myself cruising at 80km/h with the caravan and sometimes at 130km/h. Ek is maar redelik rustig, ontspanne en absent minded as ek sleep.
Chris
What do you have to do to get the speedo cruise working in manual? Please help.
Cobus