Manually locking D2 TD5 Torque converter

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Originally Posted by don3128

Ok, Its 2018, surely there is a definitive way of doing this easily other than paying lots of bucks to have it done, or a fancy kit. All I need it for is to assist in engine braking on steep descents as my brakes don't like the water at the bottom.

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You get good engine braking in 3rd lock up down steep hills as it is. With a lock up override you would get that same engine braking down to the same speed that the standard box will get to before it comes out of lock up and changes down, what you would get with the override in place is a sudden very hard change down to 2nd that would be damaging I guess.
Nick

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Originally Posted by Pippin

You get good engine braking in 3rd lock up down steep hills as it is. With a lock up override you would get that same engine braking down to the same speed that the standard box will get to before it comes out of lock up and changes down, what you would get with the override in place is a sudden very hard change down to 2nd that would be damaging I guess.
Nick

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Just did a test and in third lock up down hill engine braking all the way down to 50k and 1500rpm before it came out of lock up. I could pull away locked up anytime before that point. The only down side is not going fast enough to trigger 3rd lock up in the first place, if that state can be triggered manually under that circumstance there may be a benefit.
Nick

Ok it's 2023 and after wanting to manually lockup my TC on my disco 2 td5 auto and reading through every forum about it I decided to try. I spliced the wire from pin 32 (orange and grey) and put a switch straight to ground on it. Unfortunately it did not work for me, trying to lockup the TC under its already set threshold will just send the trans into limp mode with the M and S light flashing.

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Originally Posted by The_Mystery980

Ok it's 2023 and after wanting to manually lockup my TC on my disco 2 td5 auto and reading through every forum about it I decided to try. I spliced the wire from pin 32 (orange and grey) and put a switch straight to ground on it. Unfortunately it did not work for me, trying to lockup the TC under its already set threshold will just send the trans into limp mode with the M and S light flashing.

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Correct, that's the result I got as well.

But I probably didn't really know what I was doing, it was many years ago.

If you have a nanocom, what error is logged ?

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Originally Posted by The_Mystery980

Ok it's 2023 and after wanting to manually lockup my TC on my disco 2 td5 auto and reading through every forum about it I decided to try. I spliced the wire from pin 32 (orange and grey) and put a switch straight to ground on it. Unfortunately it did not work for me, trying to lockup the TC under its already set threshold will just send the trans into limp mode with the M and S light flashing.

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A simple spliced in switch would not work cos you have to cut the wire and use two relays, one to emulate the lockup solenoid's resistance for te TCU to not consider it open circuit and log it as error but there is a scheme which was tested and works and it seems that a relay's coil would trick the TCU for that... follow the topic untill the end from here Disco 2 - Manual/Tiptronic gearbox | Page 3 | LandyZone - Land Rover Forum or read it all if you have patience, there are steps explained at post #17 in that thread

Oh damn thanks Sierra, just read that forum and that is what I'm doing this weekend ahahaha also I dont have a nanocom shack unfortunately so dont know what code.

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Originally Posted by shack

Correct, that's the result I got as well.

But I probably didn't really know what I was doing, it was many years ago.

If you have a nanocom, what error is logged ?

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To satisfy your curiosity i can tell you that i made some tests when i helped a friend to do this mod and if the circuit is not completed well with that relay's coil(or proper resistor) the code is P0743(25) - TC lockup solenoid open or short circuit to earth (retrieved with Hawkeye) with nanocom it should be simlar

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Originally Posted by sierrafery

To satisfy your curiosity i can tell you that i made some tests when i helped a friend to do this mod and if the circuit is not completed well with that relay's coil(or proper resistor) the code is P0743(25) - TC lockup solenoid open or short circuit to earth (retrieved with Hawkeye) with nanocom it should be simlar

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Thanks for that, as I said.. It was years ago I did it, couldn't remember what code I got.

Now I just tune the controller myself, I won't be trying the manual switch but was just interested in the code.

I can recommend getting a reprogram of your TCU by shack - poster above - and BTW - really genuine bloke to deal with.
He can reprogram your TCU Sports mode to have lower lockup points - it becomes a tow mode and I seldom use normal mode now. If you also get his tune you won’t have to worry.
His mods have transformed my driving experience. I wasn’t happy at all with my td5 towing a boat across hilly terrain to the dams in SE QLD. It was always kicking down at any small hill and not really accelerating, plus economy and transmission temperatures were bad. Economy was about 16litres/100km and transmission temps were often at 80 degrees.
Now with shack’s tune and TCU reprogram, It allows me to add power gradually and hold speed uphill without all the noise and lack of acceleration on kickdown when in normal mode - call it a tow mode if you like. Transmission temps are 10-15 degrees cooler now on the same trip. Fuel economy is better by at least 3 litres/100km.
His mod is also great around town as the TC locks a lot earlier and stays locked.
I have a wideband fitted as well and I can vouch for really good AFR figures with shack’s tune. The EGT,s are fine as well on the pull uphills. My car weighs 2.5 ton with all the camping gear on board and the boat and trailer weighs 750kg as you see it in the image below.
I can give you specific EGT/AFR/ and transmission temps if you pm me.Attachment 187778

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Originally Posted by peter51

His mods have transformed my driving experience.

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Thanks for that Peter.

Yeah, that's a good way of putting it, it does seem like a different vehicle to drive, and hopefully more versatile as well.

Bit of a bonus on the fuel use, I guess that's a good indication how inefficient the auto is when unlocked, especially when towing.

Cheers