View Full Version : ECU types

10-07-2011, 03:51 AM
I have this ECU that I am trying to figure out exactly which one it is.

I am pretty sure it is an ST165 ECU as it has the 10P, 18P, 24P arrangement. It would be easy to figure out what it is except the label is nearly obliterated where the Toyota and Denso P/Ns are. It is clearly labeled "3SGT" - and I seem to read Toyota P/N 89661‑20760 on it but that can't be - because that P/N crosses over to P/N 89661‑2B290 which I would imagine has the 26P, 16P, 22P connector arrangement per regular 5th gen ECUs that I have. (P/N 89661-20761 USDM and P/N 8661-2B280 JDM)

I can't take a pic now cuz my current camera does not take good close-up pics - but I will be getting another one so when I go to California in November I can take some videos of Eric driving his car.

In the meantime - I guess my question is - were there any early 5th gen Celicas that had the old ST165 connector arrangement - and if there were does anyone know the pinouts? I am going for now thinking I have the ST165 ECU here and the pinout is for the 89661-20360 as illustrated on that aussie guy's website.

10-07-2011, 03:54 AM
Any part numbers on the PCB that could be used for identification?

10-07-2011, 04:23 AM
Any part numbers on the PCB that could be used for identification?

Nope - nothing on the top or the bottom of the PCB silkscreen except reference designators - which is odd - usually there is at least some internal PCB P/N and revision.

It is def an early board - different from thecouple I have been in so far.

10-07-2011, 09:12 PM
Are you sure it doesnt say 89661‑20360? Because that would make perfect sense then.

If you dont have it already, these diagrams will help out;

10-08-2011, 12:44 AM
Hey boo_guy,

Thanks - I think you are right - that P/N makes the most sense - though I had trouble with your link I think it is to that Aussie guy's site with all the great GT4 info.

I also did find two non-proprietary chips on the board that had date codes on them- one Toshiba and one NEC - and both date codes were 1987 - the Toshiba was week 52 (December).

The board also LOOKS older than 5th gen ECU that I have looked at in that there are no SMT components at all - they are all through-hole - and the bottom side of the PCB has no components at all.

I did find a denso P/N on the board and was thus able to figure out that the Denso P/N for that ECU is 175009-0971 from the label.

So I think this is a 87-up ST-165 ECU.

10-08-2011, 03:14 AM
Heres those diagrams I linked above