1UZ VVTi cruise control wiring

[cresslux]

Hi,

i currently have a 1uz from a UCF20 aus delivered LS400 that i'm converting into my GX81 chaser.

i would like to use the factory cruise control this built into the ecu but it appears to be done through a single wire (Pin CCS) on the ecu and then grounded through a resistor network.
i no longer have the car to find the values, but looking at the schematic, there's 3 resistors in a chain and would most likely be the same value.

any help would be greatly appreciated.

[madmont]

Why not use the cruise control switch ?

[cresslux]

i don'y have the original car, and X8 (ill be using a cressida stalk) systems don't use resistors, they run individual wires to the controller for each function.

[madmont]

Measuring the resistances on my JZS161 switch I get
On\off 0 ohms
Set 630 ohms
Res 240 ohms
and when you pull back the lever 1560 ohms

[cresslux]

perfect!

thank you very much, that's exactly what i needed.

[George]

you will also need both stop switch pins wired properly. And the option will only work in 40-100km/h range (+/- your gearing) for JDM ecus

[cresslux]

both stop switch wires?

i am aware of STP, i always wire it in with auto's as it tends to cause issues without, but whats the other one and how is it wired?

mine is an Australian delivered LS400 engine so the cruise control can do 110+kmh, i will be using a 3.7:1 diff so this should work fine.

[George]

open your scan tool, open cruise control system and you will see real time data for main and sub switch
then go to your diagrams, open cruise control system to find out the details
a free copy of original factory service manuals can be found here lexus-doc.ru

[cresslux]

ah yep just had a read, it appears a dual brake switch is required, and ST1 requires the opposite to STP.

thanks for the info, would have had me raging for a while otherwise!

[Jimmy]

Hey cresslux, how did you end up going with this? I'm putting a VVTi 1UZ with a W58 gearbox into my A28 Celica. I've got a cruise control switch panel from a 1981 Celica GT:

https://i.ebayimg.com/images/g/XGsAA...vrW/s-l225.jpg

If you have a mini write-up or something please let me know.

Things I have figured out:
Needs to be ignition switched.
Needs to run from VSS, brake, and throttle assembly.
Which pins I need in the engine ECU.

Things I'm lost on:
Totally different number of wires on my switchblock to the UCF21 cruise stalk
My W58 VSS is 3 wires and the factory A650E auto has only 2.
How to account for not being able to send a signal that the gearbox is in "D" - if I could activate this for when the clutch is used it would be awesome.

Any advice would be greatly appreciated. Cheers.

If this is hijacking the thread too much, let me know so I can delete and start a new one.

[madmont]

I have cruise control working with my 2JZGTE VVTI with manual gearbox. Set it up so the signal from the non existing transmission is "D". Used the original 2 wire VSS from the back of the gearbox to send the speed signal to the ecu

[cresslux]

i haven't finished my conversion yet, i'm simply gathering as much info as possibly before i go ahead with the wiring so i don't have to do anything twice.

are you in Perth? not many RA28's in Perth these days.

[Jimmy]

Ah, that sounds like a good plan. Yes I'm in Perth as well. There's probably only a handful that can be seen semi regularly at classic Toyota events these days. Mine isn't one of them. It's been up on axle stands for the last two years. Started the 1UZ swap early 2016 but then spare time and funds dried up. Now that I have both again I've returned to doing work on the car, with the aim to have it running properly by the end of winter.

Keep me in the loop with how you go on the wiring. I'll be keen to pick your brain!

[cresslux]

i have all the diagrams for pretty much every UZ ever made, and i have wired a fair few into various cars.

this is a personal project so i'm aiming to use as many factory functions as possible.
flick me a private message if you need any of this.