4L60E Manual convertor lock up switch.

[Laychut]

Hi,
I have seen Manual convertor lock up kits for auto transmissions in Toyota and Nissan 4wds. The purpose is to lock up the convertor in low gear while desending downhill, which in turn saves burning or wearing out your brakes.

I have fitted a GenIII 5.7 engine and 4L60E transmission out of a 2005 VZ Calais to my HJ60 land crusier. I was wondering if any one has fitted a convertor lockup kit to a 4L60E? Is it possible?

If I interrupt the wire from the ECU that controls the convertor lock up and run it through a change over relay that would be controlled by a remote switch, would this work? I am pretty sure the ECU signal is an earth, so the relay would just change the ecu signal for another earth.

Any feedback or ideas?

[Gregs]

i was actually just wondering about the same thing the other day

[slow67]

Yes the signal is earth, but I'm pretty sure that it is impossible to lock it in low (hydraulics prevent it).

[joecar]

You don't really need a relay and you don't need to cut the ECU's lock signal wire...

You wire the switch in parallel with the ECU (i.e. between the TCC lock signal wire and ground), so either the switch or the ECU can lock the TCC.

When the switch is open (floating), the ECU is free to lock the TCC (by connecting to ground).

When the switch is closed (connecting to ground), the TCC is locked regardless of ECU lock signal (floating)...

[ this is same method as is done for coolant fan override switch ]

[ hmmm, I wonder if ECU might throw a DTC for shorted TCC lock signal wire ]

[Laychut]

Hi Joecar,

your thought is correct! I came across a fault finding manual that said that a DTC would be active for a short or an open wire.
This got me thinking.....If I had the signal from the ECU sent through a relay coil while I was manually activating the TCC would it fool the ECU? I i ensured that the ohms resistance was the same as the coil for the TCC solenoid I should be ok.
What do you think?

I still have to look into Slow67's comment about the hydraulics preventing the TCC from activating in low gear. He could be right! Then I would be wasting my time pursuing this option.

[joecar]

Look at HMTG page 54B (Overdrive Range - First Gear), see 5a, 5b, 5c...

I see AFL feeding the TCC PWM solenoid, and I don't see anything to inhibit the TCC On/Off solenoid (other than it's command signal).

[smellyflange]

gday just wondering if any one has had sucsess with this switch set up

[claudiasan]

yes 4l60e transmission repair (http://www.4l60eguide.com) helps in switching the setup. just try this!

[Highlander]

Why would you want a switch when the ECU can do it when you want it?

[joecar]

Why would you want a switch when the ECU can do it when you want it?I agree... just edit the tables to apply/release the TCC at the proper times.