ST185, SWAP ECU and Code error 54

Gibs

New member
Hello to all Celica technicians and the others :)

I own a 1990 ST185 converted into a CS (gearbox, hood, intercooler + pump, fans and ECU).
The fuel pump is running permanently and of course like many guys here I got a Code 54 from the ECU.

I have read many threads about the code 54 here, but they are quite old and most of the time, the attached pictures aren't available anymore. So I have opened a new thread.

So, I would like to fool the ECU for not reporting the code 54 anymore to avoid the Check Engine light on the dashboard.

Thanks
 

alltracman78

Active member
You ground one of the pins from the ECU.
INT? I don't remember off the top of my head.
I do know the US wiring harness has a bare space there.

I always grounded it to the stud the ECU mounting bracket attached to.
 

Gibs

New member
Locker":35bnpdy4 said:
http://www.alltrac.net/phpBB2/viewtopic.php?f=21&t=50950

I just went through the same problem. Ground the int wire. There is a pin-out diagram in the thread
Thanks guys.

Did you do that inside the CPU or have you cut the wire from the ECU connector ?
 

mgnt232

New member
Locker":1fbj959o said:
Gibs":1fbj959o said:
mgnt232":1fbj959o said:
I had the same problem code54, thread has all my info and pics. Worked for me
http://www.6gc.net/forums/index.php?showtopic=90820&hl=

Thanks.
So wich relay do I need ?

Do you have a picture of the mod done ? :D

The relay fix is only for those running a st205. If you've done the St185 RC swap you only need to ground the INT wire. I went through this headache not 2 weeks ago...
Oh yeah sorry gotcha, ST185 is different. disregard for you lol, it is how you do it on a 3rd gen st205 though
 

Gibs

New member
Locker":7qh6j5hz said:
Gibs":7qh6j5hz said:
mgnt232":7qh6j5hz said:
I had the same problem code54, thread has all my info and pics. Worked for me
http://www.6gc.net/forums/index.php?showtopic=90820&hl=

Thanks.
So wich relay do I need ?

Do you have a picture of the mod done ? :D

The relay fix is only for those running a st205. If you've done the St185 RC swap you only need to ground the INT wire. I went through this headache not 2 weeks ago...
Thank you very much. Now it's clear :)
 

Gibs

New member
So I own the Carlos Sainz ECU.

Based on this information,
CarlosSainzECU.jpg


My INT pin should be here :
gibsECU.jpg


The INT pin should be there:
20151104_201043.jpg


And is grounded there
20151104_201106.jpg


But the Check Engine is still lightning...
While removing the ECU I have disconected the ground from the battery.
Should it be enough to reset the ECU ?

Or maybe I have grounded G- instead of INT ?

Thanks
 

Locker

Member
I'm not sure what to tell you.
I grounded the INT and my check engine light went off. It was an ST185RC. its a pink wire.....
I'm not sure why you opened up the ECU
 

Gibs

New member
Locker":2wdy6ncp said:
I'm not sure why you opened up the ECU

To do the mod inside the ECU. (I have no electricity to solder in my garage).
So I took the ground of the ECU.
 

alltracman78

Active member
alltracman78":21yjugn1 said:
You ground one of the pins from the ECU.
INT? I don't remember off the top of my head.
I do know the US wiring harness has a bare space there.

I always grounded it to the stud the ECU mounting bracket attached to.

.
 

Locker

Member
Gibs":cdugx4ze said:
Locker":cdugx4ze said:
I'm not sure why you opened up the ECU

To do the mod inside the ECU. (I have no electricity to solder in my garage).
So I took the ground of the ECU.

I believe your thinking too much. This is a SUPER easy fix for the 185RC.
All you need to do is snip the INT wire. then ground the wire from the ECU side of the harness.
 

Gibs

New member
Locker":1pywoaf1 said:
Gibs":1pywoaf1 said:
Locker":1pywoaf1 said:
I'm not sure why you opened up the ECU

To do the mod inside the ECU. (I have no electricity to solder in my garage).
So I took the ground of the ECU.

I believe your thinking too much. This is a SUPER easy fix for the 185RC.
All you need to do is snip the INT wire. then ground the wire from the ECU side of the harness.

hehe thanks for your help. :notworthy:
I think we never think too much. :roll:

Since the beginning I'm talking about the CS mod and you are talking about the RC.
I did the conversion 10 years ago, and at the time a friend did it before me and his fix was to remove the check engine bulb (in his car) :)

So now, I want to fix it properly.
I admit, I did not snip the INT wire. I just put it to the GND. The reason is that it my intercooler is not managed by the ECU anymore : when I start the car it runs until I stop the car.

I also own a Japanese ECU (the RC one), and from what I remember It doesn't report the code 54 without any tricks. The reason I don't use the RC one is because I think it is better to run with an european ECU (no need to raise the octane %).

So even if the car is running correctly there are still pinouts that doesn't match.

GT4-GT4CS%20ECU%20Pinouts.jpg


Also the 26 & 16 pins harness is from the CS, while the 22 pins is from the car. Maybe there's something to do with the WIN pin...

Can you confirm that my INT pin is this one ?

ECU%20Connector%2026.jpg
 

underscore

Well-known member
If you want to confirm the pinout I believe Toyota usually labels the pins on the PCB inside the ECU case.
 

Locker

Member
Gibs":2ebqffp5 said:
Can you confirm that my INT pin is this one ?

ECU%20Connector%2026.jpg

from what I can tell that is the right PIN. it was a pink wire in my car with a stripe I believe.....
I'm no electrical guru. I was shown the pin out diagram told to cut the INT wire and ground it and boom no light and the car no longer ran in limp mode.
 

Gibs

New member
Locker":29x3iqps said:
Gibs":29x3iqps said:
Can you confirm that my INT pin is this one ?

ECU%20Connector%2026.jpg

from what I can tell that is the right PIN. it was a pink wire in my car with a stripe I believe.....
I'm no electrical guru. I was shown the pin out diagram told to cut the INT wire and ground it and boom no light and the car no longer ran in limp mode.

Locker":29x3iqps said:
I've grounded the WIN pin.... that's why I'm confused... I must be missing something. I read somewhere about wiring 2 resistors in parallel at the pump but I thought grounding the WIN pin eliminated the need for that?

Ok, in the thread you have opened you're also talking about the WIN wire.
Did you kept the WIN pin grounded also ? Thanks
 
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