Auto ECU without engine ECU

[Billzilla]

On my MX83 (still with that nasty ol' 7M in it!) the auto ECU is connected to the engine ECU via 3 wires: L1, L2, L3. I am presuming if when I fit a Motec I (heaving forbid) turf the airflow meter (or better yet, please, the entire 7M EFI system!) the auto ECU won't be happy? Has anyone ever done anything like this before? Maybe I should try measuring/scoping L1 etc. and make the Motec output something similiar? Someone has to know something about this!

If it's an M400 or better, you can get the Motec to control the box.

[mrshin]

Seems to only need L1, L2, L3 and IDL (OD1 I presume is temperature dependant for top gear, and need only be left permanently 'warm')

If I was to use M800 aux outs for L1, L2, L3, I could then have (some) control over gearshift points as well.

[mrshin]

Bill: I'd like to do this, but I don't really see how to get any hysteresis into the shift points, and when I asked Motec they said the same thing. If you know more than I, hints will be rewarded with, uhmm, well, a big smile

[Billzilla]

Bill: I'd like to do this, but I don't really see how to get any hysteresis into the shift points, and when I asked Motec they said the same thing.

Ask someone else at Motec.
Not everyone there knows everything, clever as they are.

[mrshin]

Shall try!

[Mos]

L1, L2, L3 are a binary representation of the TPS (but you probably found that in another thread [where it was mentioned ]).

Mos.

[mrshin]

Yah, I managed to find a bit of stuff on it, looks like it should be easy enough to make something up to 'fake' it

[sideshow]

from what ive seen only 3 things determine shift points

tps
rpm
and spd

you will need speed signal that goes to speedo then back to ecu
rpm you might have a prob cause u have a v8 rpm signal into a 6cyl auto ecu
might cause probs not sure and even more probs is the 1uz has a 4cyl tacho output


tps is easy

but be prepered for some shit to fuck up
as most of the time what yr doin is trial and error and thigns will fuck up

u can even try finding a 4cyl camry auto only ecu

might be bit easier to trick
i had diagrams somewhere on them in my junk

[MacroP]

There's also Hilux Surf's 2.4L turbo diesel(LN130) 4cylinder with the A343F. These have a seperate Auto ECU(mounted near the shifter). The A343F is identical control to the A340E with an extra temp switch near the oil pan. Has O/D on/off and ECT power mode. Plenty of Surfs around like these at the wreckers. Most are Automatic. Unfortunately I haven't seen any wiring diagrams for these.

[mrshin]

From what I can see, it doesn't look like there's even an RPM input. There's L1, L2, L3 and IDL for throttle, OD1 I presume is a temperature switch for top gear, and that's about it for connection to the engine ECU.

[MacroP]

I've wondered what these do myself. I was also thinking that OD1 could be related to TC lockup somehow and maybe L1,L2, and L3 come from the engine ECU to hold the each gear longer or something depending on engine temp, TPS position or ECT power mode etc etc. Be interesting to know.

EDIT: Just reading those Toyota online manuals L1,L2,L3 are basic throttle positions sent via the Engine ECU. And OD1 is overdrive control based on temperature. Cool.

[sideshow]

surf ecus are totally different

they have 2 throttle sensors and shit like 4wd solenoids etc
the surf ecu does the 4wd part aswell

[MacroP]

Whoops double post

[sideshow]

ive got a 1ggte auto ecu if u want to buy it

after new year i have to clean garage and throwing shit out

it looks similar to a 7mgte auto ecu

only thing i dont have a matching plug for it

[mrshin]

Thanks sideshow, but I've already got a 1G ECT box + plug (and a few others if I dig through junk!)