Electrically disconnecting the front Diff - ADD models only

[jcarter]

i will add that looking in the EWD again for noel.

the T3 Connector, is Listed as being BLUE.
shows as a 2 core connector, but possible only 1 wire. which is as per the images above.

If the vehicle has ADD that blue cord should goto the 4WD ECU on the pas side of the car.

No ADD, and it terminates @ Junction J6(might be 40)

The above is valid for Diesel models.

Petrol model and 4WD ECU is the same
but Terminates @ Junction J33 (practicly the same place).

i have no ADD so i cant realy test.
i can probably find the wire on the gearbox that detects the change, as the same switch that turns the ADD on, turns the switch on in the dash from what i can see, so all i could say for sure if i tried it was if the switch on the dash came on or not ^_^.

[TOMUCH]

Had a look at mine too.. but been too busy to disconnet it. ( Mine is not very accessable..big hands) The process seems feasable, and given time I thing I might give it a try. will let you all know when I do. Cheers TOMUCH

[SR5 2NV]

Just an update on this.
I have unplugged the 4WD ecu behind the glove box, when i put it in 4H or 4L the front diff is not connected. So when it is in 4L it is actually in 2L. I only ever unplugged or plugged in the 4WD ecu when the car was turned off just in case it done some damage to the circuit.

I know it is a long way to do this but it worked for me.
The 4WD ecu is the green plug.
Cheers Metin.

[shane308]

so would i be correct in thinking you could leave the green plug plugged in but put a switch in that circuit to disconnect the front diff, that would be handy

[mylux]

Has any one finished this project on there lux yet I would love to do this as well as I tow a very heavy trailer and have to start off in low .
Can I just clear some thing up is the wire on the gear box or the diff ?
What are the Junction J numbers are they on the plug or ECU ?
regards

[Batman]

Guys,

Have been watching this thread closely, haven't done much but look at the electrical diagrams. From what I can gather from the diagrams I have The switch for detecting 4wd is listed as T3 as stated by jcarter. But I determine that the wires are black on the positive side and black with white trace on the negative or earth side of the switch.

The black wire goes to the 4wd ECU at Pin 6 behind the glove box. If this wire is cut and switched it will disconnect the ADD and all warning lights. To test simply remove the plug from the ECU and unlock the wire, remove the wire from the plug then reconnect and see if the ADD works. I will scan the diagram and post on here as a photo image when I get a chance.

I will test all this theory tomorrow if I get time. Will let you know of the results...

Cheers.
Steve.

[Batman]

Guys,

Have confirmed that the black wire at pin 6 on the 4WD ECU plug is the one. The last three photos on my profile show the plug and the wire in question all you need to do is cut it solder on a wire to each cut end then run the wires to your desired switch position and fit switch. Whammo you have an manually switched ADD.

To test I disconnected it by removing from the plug and jacked up the rear wheels, ran the vehicle in high and low range and the ADD did not activate. No other issues arose, no ABS light or any other problems.

I priced a genuine difflock switch out of a Prado but was too much at $120 so I bought a switch from auto shop and will fit this weekend.

Any questions let me know.

PS does anyone know how to post photos in the thread?

Steve.

[shane308]

well i done it today, and it works great, using the pics and info posted by batman (thanks batman) i put a switch in the little removable plastic panel in front of the handbrake so its easy and quick to find, so no more stinking clutch or binding up the t/case while reversing the trailer up steep driveways

[4Hilux]

Thanks Batman - done mine today too, & it works well............

Heres a link to my electrical mods for power windows, & turning ABS off....................

viewtopic.php?f=11&t=2231

Cheers.

[KWTRUK]

has someone put up a thread of this with clear instructions cause i got lost!! and would love to do this...but....im still not sure if its possible with ALL the hiluxs? i got a 03/2006 SR D4d Single Cab Chassis Manual.......

[Batman]

kwtruk,

No-one has done a step by step guide on it to my knowledge.

However all you need to do is.....

1, Remove the glove box and locate the 4WD ECU, located on the LHS of the glovebox and mounted on the side of a supporting metal structure of RHD vehicles. It has a green plug going into it.
2, To test you have the correct ECU disconnect the plug and then engage 4WD, with the ignition on no 4WD light should be on.
3, On the green plug there are six (6) wires coming out of it. Locate the black wire, check my shed profile and have a look at the photo of the plug and the wire in question.
4, Cut the black wire, solder two lengths of wire (a few feet long, or long enough to reach your desired switch position), one to each cut end then connect the lengths of wire to a switch to complete the circuit.
5, Fit the switch in your desired position. Replace the glovebox.
6, Hey presto you now have a manually disconnectable front differential.

Hope this helps if not them PM me and I will send you some more detailed info.

Cheers,

Steve.

[Naci]

I have done this mod today and I'm very pleased with it.

kwtruk,

No-one has done a step by step guide on it to my knowledge.

However all you need to do is.....

1, Remove the glove box and locate the 4WD ECU, located on the LHS of the glovebox and mounted on the side of a supporting metal structure of RHD vehicles. It has a green plug going into it.
2, To test you have the correct ECU disconnect the plug and then engage 4WD, with the ignition on no 4WD light should be on.
3, On the green plug there are six (6) wires coming out of it. Locate the black wire, check my shed profile and have a look at the photo of the plug and the wire in question.
4, Cut the black wire, solder two lengths of wire (a few feet long, or long enough to reach your desired switch position), one to each cut end then connect the lengths of wire to a switch to complete the circuit.
5, Fit the switch in your desired position. Replace the glovebox.
6, Hey presto you now have a manually disconnectable front differential.

Hope this helps if not them PM me and I will send you some more detailed info.

Cheers,

Steve.

[jakelux]

Done. I wish i did this mod years ago, perfect for backing up my tandem mini digger trailer in tight spots on bitumen roads!!
I got a pretty neat switch by scrathing off the spotlight decal on an ARB switch and sticking on a L2 one that i printed out.

[jsa2009sr5]

This is great.

Thanks for the step by step, I regularly reverse a 2 tonne trailer up my driveway and the clutch was taking a beating, will do this mod on the weekend.

jsa

[jakelux]

Does everyone think its safe to switch the switch on and off at high speeds?? (40 - 60 KPH) for example on some country roads where it alternates from sealed bitumen to loose gravel it would be good to be in H4 on the unsealed and then switch to H2 when the bitumen is coming up? (without having to stop/slow down to switch)...

[Batman]

Does everyone think its safe to switch the switch on and off at high speeds?? (40 - 60 KPH) for example on some country roads where it alternates from sealed bitumen to loose gravel it would be good to be in H4 on the unsealed and then switch to H2 when the bitumen is coming up? (without having to stop/slow down to switch)...

I personally wouldn't do it but if you are driving in a straight line with no wheel slip is probably can't hurt anything. If I was to do it I would leave the switch out of it and use the lever and switch between H2 and H4.

I only ever use the switch whilst using low range and backing trailers.

[Uncle]

Is there only 1 spot for the 4wd control ecu (f14 on the ewd)? Armed with the photos and instructions supplied by batman i set out to make this mod, but i can't locate my 4wd control ecu. I went to my local toyota dealer today only to be given a blank look (no charge)

Has any body else attempted this mod and come across the same as i have ?

my build date is january 2007, SR, dual cab, diesel

I thought a couple of beers and i would have it all finished, not so.


Uncle

[jakelux]

I only ever use the switch whilst using low range and backing trailers.

Yeh me too batman, but found it pretty handy on the loose gravel for more traction in 4H then flick back to 2H when i hit the Bitumen, gave it a try the other day doing about 20-30 k's and couldn't really see a problem with it.

Uncle,
Mate this Mod only works on the SR5's, as the SR's do not have ADD.

[Uncle]

thanks jakelux, that would explain why i couldn't find it.

[Rebs]

Anyone done this mod to a 07/2010 SR5 D4D Auto Dual Cab or later?
Just want to check that Mr Toyota hasn't made changes to the electrics before I chop the black wire and fit the switch.