aristo trans wires from ecu

**darby** · 03-01-2010, 05:02 PM

can anyone help me with identifying which ecu terminals i need to connect overdrive switch, power/economy, stop light, kick down etc. on a jzs147 2jz-gte ecu in my mx73? cressida side of things are easy, just running out of patience trying to get info/ pin outs for the jzs147 aristo (as does everyone).

**wilbo666** · 03-01-2010, 05:37 PM

I'm in a bit of a hand holding mood

Also see references below...

A-28 = OD2, Overdrive switch - This pin has +12V when OD is On, and GND when OD is off (+12V is via OD light)
A-18 = M, Power/Economy - This pin has +12V when in Power Mode
A-4 = STP, Stop light - This pin has +12V when brakes are On
A1-3 = KD, Kick Down Switch - This pin is grounded when accelerator is fully depressed

Autoshop101 Tech Articles
http://www.autoshop101.com/forms/h16.pdf
-Page 10 for OD switch wiring
-Page 9 for stop light

Cheers
Wilbo

**darby** · 03-01-2010, 06:01 PM

thanks heaps wilbo, that really helps. i had already looked through the old forums and was intending to wire it as per that picture but was a bit unsure as i presume this was for jza80 not aristo. has got me stumped as pin a28 has approx 4.5v with ignition on and engine running? presumed that there would be no voltage as i have not connected the od switch wire from the cressida and from what i understand the ecu should recieve power to that terminal from the od switch in the car. does it seem correct for it to have the 4.5v power? im a mechanic not a sparky and a bit hessatant to connect 12v power from the switch to a terminal that has power on the ecu already? ... hope that makes sense, just dont want to fry my ecu and would love to get out of 3rd gear

**wilbo666** · 03-01-2010, 06:14 PM

Hearing that I suspect there is a pull up resistor to 5V inside the engine ECU that passes to the OD switch via a diode (to stop the +5V feeding into the engine ECU).?

Unless you have the engine ECU flashing the OD2 light (Auto trouble codes) and it has an internal pullup to +B? (+12V)?

I would have thought that being the case however that you'd always be stuck with overdrive enabled...

Also A-28 is the pin I used (JZS147 ECU) anyway

Cheers
Wilbo

**darby** · 03-01-2010, 06:27 PM

thank you very much, you should be awarded a medal for the amount of people you have helped with this stuff

i would have thought the same with the overdrive being always enguaged but she's defenetly a 3spd with lock up clutch at the moment. i'll connect it and give it a try later (no responsibility on your head

). also would you be able to guide me as to which wire power's the converter clutch so i could maybe have manual control over the clutch operation? sorry to be a pest

**wilbo666** · 03-01-2010, 06:56 PM

Other things I can think about in regards to your overdrive are make sure that OD1 is connected correctly (this is overdrive control from the cruise control ECU).

And check that the trans temp is above what is needed for the auto to shift into OD.

Actually I've just had another thought... perhaps you are measuring 4.5V at the OD2 pin because your OD light is flashing, indication auto trouble codes?

One thing I have seen missed a few times before is the position indication wiring (L,2,D,R etc)...

Originally Posted by darby

Also would you be able to guide me as to which wire power's the converter clutch so i could maybe have manual control over the clutch operation?

SLU- is for the Lock Up Clutch Converter. The engine ECU connects this pin to ground internally to lock up the clutch. You can place a switch in parallel with SLU- wire to ground to have manual control.

Cheers
Wilbo

**darby** · 03-01-2010, 10:32 PM

hmmmm od1 cruise control? not sure what to connect that one to as it's a late'84 mx73 with no abs or cruise control from factory (air con also went in the bin to save weight as its just a budget bare bones sleeper)

connected up od2 and went for a drive, still no od on/off control from switch. light on dash looks pretty when i flick the switch but hey it was doing that before. it's defenately not flashing any trouble codes either.... (scratch my head).. position indicators for dash display (12DNRP) are connected and functioning. dont have speedo or sp1 connected yet but didn't think that would hurt as sp2 is the main input and can run solo. guess i'll just finish the other wiring (without od1) and try it and if nothing happens it may be a fault in the trans itself? lucky for me mv's are only 1 hour up the road

guess thats one up side to living in s.a.

forgot to add- drove far enough to get trans up to temp, didn't just zip around the block