Disco 2 Manual/Tiptronic gearbox

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DrecklyD2

DrecklyD2

Active Member
Posts
93
Location
Dartmoor
I know there’s a lot of you old and bold out there that have heard this before from Newbies to the Dicovery 2 world. The awful D2 auto gearbox that does some pretty random things with no reason why. I have gone down the usual route of larger wheels and have found that the gearbox will not change when I think it should, so l have put together a series of relays and resistors linked to the xyz switch so I tell it when to change gear by shifting through the 1,2,3,D. I have also fitted a TC lockup switch which makes a massive difference. Testing is on going and working well and if anyone is interested pictures to follow. Knowing what I know now I should have bought a manual
Just thought some maybe interested, but if not it’s kept me entertained
 
The name ‘Tiptronic’ was or is trademarked by Porshe, although there now there variations of it, in the last 10 years my two cars have had similar so I'm to happy with the use of the “flappy paddles “ to knock down a ratio or two when over taking but thats it, 80% of the time I stay in drive.
Anyway my only experience of a D2 auto gearbox was with D2 demo vehicles and I found there was no difference from the one fitted to the RR or disco or before it.
So my opinion is, your vehicles gearbox or it's controlling software has an issue.
 
Wife's Pluriel (Citroen C3 thing) has a flappy paddle gearbox, which I don't like at all. It can be positively dangerous if you leave in full auto. so the only way to drive it is by paying strict attention to what it is doing and controlling it with the paddles.

My D2 TD5 auto on the other hand is pretty good. Changes pretty sensibly but obviously not like a manual.
But do agree it would be nice to be able to get lock up at lower roadspeeds.
Interesting what work you have done.
Was there a reason you didn't just change it back to manual?
 
DrecklyD2 said:
I have gone down the usual route of larger wheels and have found that the gearbox will not change when I think it should,
Click to expand...
That's because the whole electronic management is mixed up(not just the TCM) as it was calibrated from factory for std dimension tyres... the "usual route" of larger wheels should be usual only for vehicles which dont use the VSS(vehicle speed signal) as part of the management. Now fit an EGT gauge and maybe you'll see that the gear change was not the only problem you created yourself with the big tyres... and be aware with the braking distance too, more info here: https://www.landyzone.co.uk/land-rover/255-65-or-255-70-pros-and-cons.292220/#post-3620824

in a nutshell: all you get with big tyres on a D2 is some extra ground clearance and a "macho" look while you loose everything else. The only correct way to make it run well with bigger tyres is to use a speed signal corrector and a dynamic remap to addapt the fuelling and torque management for those tyres
 
Last edited:
Stanleysteamer said:
Wife's Pluriel (Citroen C3 thing) has a flappy paddle gearbox, which I don't like at all. It can be positively dangerous if you leave in full auto. so the only way to drive it is by paying strict attention to what it is doing and controlling it with the paddles.

My D2 TD5 auto on the other hand is pretty good. Changes pretty sensibly but obviously not like a manual.
But do agree it would be nice to be able to get lock up at lower roadspeeds.
Interesting what work you have done.
Was there a reason you didn't just change it back to manual?
Click to expand...

I do have a master over ride switch which puts it back to normal auto for the wife because as you suggest you need to know what you’re up to.
I didn’t go to manual as I like a challenge
 
sierrafery said:
That's because the whole electronic management is mixed up(not just the TCM) as it was calibrated from factory for std dimension tyres... the "usual route" of larger wheels should be usual only for vehicles which dont use the VSS(vehicle speed signal) as part of the management. Now fit an EGT gauge and maybe you'll see that the gear change was not the only problem you created yourself with the big tyres... and be aware with the braking distance too, more info here: https://www.landyzone.co.uk/land-rover/255-65-or-255-70-pros-and-cons.292220/#post-3620824

in a nutshell: all you get with big tyres on a D2 is some extra ground clearance and a "macho" look while you loose everything else. The only correct way to make it run well with bigger tyres is to use a speed signal corrector and a dynamic remap to addapt the fuelling and torque management for those tyres
Click to expand...

Thank you
 
DrecklyD2 said:
I do have a master over ride switch which puts it back to normal auto for the wife because as you suggest you need to know what you’re up to.
I didn’t go to manual as I like a challenge
Click to expand...
I did once see a post, with a fairly unclear, hand drawn diagram of how to wire in a switch to work the lock-up independent of the way the box did it.
In France where we drive it half the time, the limit on A road equivalent is either 80 or 90 kph. It is SO hard to get it lock up at either of these speeds and if I manage it, soon I have to drop out of it. So one of those would be really handy. I wouldn't need the rest of what you have.
As @sierrafery says the whole auto electrickery gets bamboozled by a change to the wheel/tyre diameter, which is obvious even to me, and I am thick when it comes to electronix! Maybe it could be brought more in range if you changed the diff ratios.
I have standard wheels and tyres so I know it is unlikely to hurt the vehicle.
As it is I have to put it into 3rd if I want lock up over 30 mph. But this means it revs higher and is more uneconomical.
We also live in a mountainous district so that can make driving a little annoying.
BUT, that said, for an auto it goes pretty well.
I only bought it cos a meningioma meant I couldn't drive for a while so my wife had to do the towing and she can only drive an auto due to a foot problem!
Fascinating!:):):)
 
I have been looking at so many forums but nobody seams to be able to do it. I found an Aussie company charging $400 for a kit so I thought I'd have a go myself. I can show you how to make one for less than £20. I'm at the pub right now but will continue this when I get home.
 
sierrafery said:
That's because the whole electronic management is mixed up(not just the TCM) as it was calibrated from factory for std dimension tyres... the "usual route" of larger wheels should be usual only for vehicles which dont use the VSS(vehicle speed signal) as part of the management. Now fit an EGT gauge and maybe you'll see that the gear change was not the only problem you created yourself with the big tyres... and be aware with the braking distance too, more info here: https://www.landyzone.co.uk/land-rover/255-65-or-255-70-pros-and-cons.292220/#post-3620824

in a nutshell: all you get with big tyres on a D2 is some extra ground clearance and a "macho" look while you loose everything else. The only correct way to make it run well with bigger tyres is to use a speed signal corrector and a dynamic remap to addapt the fuelling and torque management for those tyres
Click to expand...

I live on Dartmoor so the ground clearance is a must, on top of 33 inch wheels is an 8 inch lift. But rest assured that ABS and stopping distances are not an issue as so many holiday makers never do more than 20mph, hence the TC lockup. I don't think my truck has ever done 50mph. I fully take on board what you have said and appreciate your advice.
 
DrecklyD2 said:
I have been looking at so many forums but nobody seams to be able to do it. I found an Aussie company charging $400 for a kit so I thought I'd have a go myself. I can show you how to make one for less than £20. I'm at the pub right now but will continue this when I get home.
Click to expand...
Don't rush your beer!
We have time!:):):)
and thanks!:):)
 
This is a pic of the relay setup that enables me to change gear when I want running through the sequence 1-2-3-D.
I find this works really well for me and where I live, it’s not for everyone but it’s be interesting getting around the constant self diagnostics of the TCU.:)
 
You’ll need a switch, some wire, and a standard 30amp relay.
The reason for using a relay instead of a large resistor is it acts as a fail safe for the TCU. Even though you have manually energised the TC lockup the TCU still thinks it’s in control and will when it thinks it’s right will energise the TC. If a resistor is used it will short and put it in limp mode. So the TCU thinks it’s doing its job as it should.
The other reason is the TCU is constantly monitoring the system, if you splice in or cut the TC wire it will throw a fault and again enter limp mode. With the relay connected the TCU sees this as a connection to the Solenoid Valve as thinks all is well. Ok now I have bored the hell out of you here’s what you need to do.
1. Find pin 32 on the TCU, cut this wire but not too tight to the TCU.
2. Connect the wire from pin 32 to one of the pins on the relay. Either the + or - that energises the relay.
3. Connect a wire from the opposite side of the one you have just connected on the relay and splice it in to the wire on pin 53 which is the power supply to the solenoids. This connection allows the self diagnostics to see what it thinks is the solenoid valve.
4. Connect a length of wire to the wire that was connected to pin 32. Connect this to one terminal on your switch and the other to a good earth.
5. When you operate the switch you are supplying a direct ground to the TC solenoid valve which will energise it and lock your TC. You can do this in any gear, but don’t let it change gear when locked.
I hope all this makes sense, but let me know how you get on and if you have any questions please feel to ask.
Cheers
Tom.
 
DrecklyD2 said:
You’ll need a switch, some wire, and a standard 30amp relay.
The reason for using a relay instead of a large resistor is it acts as a fail safe for the TCU. Even though you have manually energised the TC lockup the TCU still thinks it’s in control and will when it thinks it’s right will energise the TC. If a resistor is used it will short and put it in limp mode. So the TCU thinks it’s doing its job as it should.
The other reason is the TCU is constantly monitoring the system, if you splice in or cut the TC wire it will throw a fault and again enter limp mode. With the relay connected the TCU sees this as a connection to the Solenoid Valve as thinks all is well. Ok now I have bored the hell out of you here’s what you need to do.
1. Find pin 32 on the TCU, cut this wire but not too tight to the TCU.
2. Connect the wire from pin 32 to one of the pins on the relay. Either the + or - that energises the relay.
3. Connect a wire from the opposite side of the one you have just connected on the relay and splice it in to the wire on pin 53 which is the power supply to the solenoids. This connection allows the self diagnostics to see what it thinks is the solenoid valve.
4. Connect a length of wire to the wire that was connected to pin 32. Connect this to one terminal on your switch and the other to a good earth.
5. When you operate the switch you are supplying a direct ground to the TC solenoid valve which will energise it and lock your TC. You can do this in any gear, but don’t let it change gear when locked.
I hope all this makes sense, but let me know how you get on and if you have any questions please feel to ask.
Cheers
Tom.
Click to expand...
Thanks very much for this.
i'll read it tomoz cos I am sh!t at understanding maths, physics etc in the evenings. My brain just doesn't work well.
but I am grateful ever so much for you having bothered to try to explain this stuff to me.
But just ojne thing before I sleep on all, this.
TCU? Is that what most of us call the BCU? and is it the triangular thing under the passenger seat?
Cos altho i have taken the ECM out loads of times I have never touched the BCU.
Sorry to ask such a basic question.
The rest of it seems to be simply a question of wiring like wot I am used to, relays etc.
Once again, thanks.
Stan:):):)
 
sierrafery said:
TCU means "transmission controll unit"(named EAT ECU in RAVE), BCU is the body controll unit, not involved in shift controll
Click to expand...
So it wasn't that stupid a question then. Good thing I didn't start playing with the wrong box of tricks.
I'll be reading RAVE thoroughly before going any further!;)
 
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