Fitting M4 ecu into a st205 celica GT4. Almost done

Discussion and support for MoTeC's earlier generation ECUs

Fitting M4 ecu into a st205 celica GT4. Almost done

Postby pc18 on Fri Aug 22, 2014 7:20 am

So the plan is to swap my motec ecu from one st205 loom to another.

so i have the pin out from the motec forum which is available on this link http://www.motec.com/forum/download/file.php?id=529&sid=b40e7cf3f2d60c30dec7a6a98fa4f751

heres a pic of the pinout

Image

so ive been going through the existing wiring which i believe was done by Adrian at fensport and he then mapped it.

I noticed a few things which are different when ive been following the pin outs above.

starting with motec pin number 3 which should be injector cylinder 3 and wire colour Black-Red well mine is Black white and pin 15 which should be injector cylinder 2 is Black white instead of Black red so i t looks like these are the wrong way round. but does this matter if these cars are batch injection?

other things ive noticed are
pin 19 should be speedo input with an orange wire but i have no wire to pin 19 but i have an orange wire going to pin 20 and this then goes to a white connector which goes in the dash.

pin25 which should go to c13 goes somewhere else, maybe this doesn't matter if it is just a ground?

im not sure about the air temperature pins as I think only pin 29 is connected on mine and this is a grey wire

pins 30,31, and 32 have nothing going to them.

I have nothing going to pin 34 which is idle open RSO?

pin 35 has a black white wire to it but the pin out says it should be green - red / pink blue?

pin 36 goes to pin 4 on the main relay??

are pins 34 and 36 for launch control? as far as i know this was never setup on my car.

also how does the motec control the boost i notice there is a pin 13 for boost control but how does it control it, is there a standard solenoid somewhere it uses?

could it be that only the bare minimum has been connected up to map the car so some haven't been used?

thers quite a bit there but any help sorting these pins out would be most appreciated as i want to make sure its right instead of just copying what was already there in the other loom.
Another thing is the pinout and wire colours correct on that motec info sheet??

Thanks Guys

This is the car in question

Image
Last edited by pc18 on Fri Nov 28, 2014 7:40 am, edited 1 time in total.
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Re: Fitting M4 ecu into a st205 celica GT4. partly done!

Postby pc18 on Mon Aug 25, 2014 8:46 am

anyone got any ideas or should i just copy exactly how it was fitted into the other car even if it might look different to the motec wiring diagram?
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Re: Fitting M4 ecu into a st205 celica GT4. partly done!

Postby stevieturbo on Mon Aug 25, 2014 9:01 pm

A lot of your queries should be answerable by looking at the map that was used in conjunction with the loom, to see what I/O's were configured and set up for.

Injector numbers can sometimes be confusing.

Is it injector number or firing order number ? Really you'd need to test this, but you could re-configure in the software anyway to ensure correct injector firing sequence.

Speedo input, nice to have but not essential unless you need it for some modes of control. Again you'd really need to test if there is any doubt about what the wire is doing.
Sometimes car makers change pinouts for no reason, and wire colours are not always reliable for same reason.

OEM ecu's may often have far more grounds than aftermarket, so again can be confusing. Some may be needed, some not

Air temp signal will be one wire. That sensor along with other sensors will have a common sensor ground. This may relate to a single pin on the Motec which is then split elsewhere within the adaptor or car loom itself.

Idle control, maybe the Motec isnt being used to control an idle valve. It wouldnt be uncommon.

Again, wire colours cant always be trusted unless you are 100% sure the wiring diagram is accurate for your exact model and age of car...and even then sometimes manufacturers just change things.

34/36 may be something to do with Anti_lag, that is a separate feature from launch control.

The Motec may be used for boost control or it may not. You'd need to look at the software as to how the map was configured.
There may have been no control other than base wastegate, or some mechanical bleed valve, an external electronic controller, or it may have been Motec via a solenoid. You would need to establish that
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Re: Fitting M4 ecu into a st205 celica GT4. partly done!

Postby pc18 on Fri Nov 28, 2014 6:56 am

thanks for that detailed response. Ive been on with doing other work on the car.

I cannot check the map on the ecu as the wiring for the car isn't complete.

I have managed to figure out most of it (i think)
My friend lent me a m4 manual which explained some of the inputs on different pins.
What was confusing me was that my car which used to be running on the ecu. before the fire and the loom was damaged under the bonnet. And it seems to be wired up differently to what the motec pdf wiring table states.

one thing im not sure of still is pin 35 which should be fuel pump relay using motecs diagram but mine seems to be on pin 36. however i am not sure what was connected to my pin 35. i cannot trace it as the loom is badly damaged. the other imput left on the motec table states EGR/ALS VSV i cant figure it out.

also looking at the old loom there is other wires which have been cut but i cannot tell where they went to. i think i will need to get someone who knows these ecu to check this over. i very much doubt there is any one in cumbria though.
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