Using a '93 3SGTE ECU on a '91 3SGTE Engine and Harness Options

[Dr_Tweak]

Some weeks back I had a customer doing a 3SGTE swap into a '91 Celica that I did a wiring conversion for. After he got it back and installed, I asked him for the part number on his ECU since I've seen many situations where the importers send the wrong ECU for the year of the harness. Sure enough, he had a '91 Harness but a '93 ECU. I advised him to get a '91 ECU, but he was having a hard time locating one.

About the same time, I started gathering parts and doing research for making jumper harnesses for various Toyota applications. I located the supplier for the female ECU plugs for a few different Toyota harnesses. When I got one in that matched the 3SGTE harnesses, I though, why not make a jumper harness that goes from a '91 harness to a '93 ECU, or a '93 harness to a '91 ECU? Then customers who run into this situation don't have to find another ECU or repin the whole harness.

Since I had this customer, Bryant, who had this very situation at hand, and since I happened to be going near where he lived on a recent road trip, I decided to whip up a prototype and give it a try.







There it is plugged into a 3SGE ECU as an example. This first one came out a little rough, the production model will be cleaner.

And here it is plugged into the car:



The jumper harness worked PERFECTLY. It fired up the first try and is running great, no codes and no problems at all

If anyone wants one of these jumper harnesses let me know, I'm currently building them to order.

Other applications for this setup include plug and play jumper harnesses for standalone units that don't already have a plug and play setup, like perhaps 3SGTE/Autronic, and so on.

-Doc

[WannabeGT4]

I was curious about the mark up on this so I did a little research. These are the part numbers and prices from Toyota:

26 Pin Connector
90980-11390 $5.09
?alt?90980-11423 $5.09 ?alt?

22 Pin Connector
90980-11392 $5.06
?alt? 90980-10765 $5.66 ?alt?

16 Pin Connector
90980–11391 $5.07

Not 100% sure about this one since it didn't have a picture:
PCB Connector 64 pin
90980-11576 $8.52

The terminals that go inside each connector are easily obtainable from places like mouser.com or digikey for pennies a piece. The terminals with wires pre-crimped are also available from Toyota but without some in front of me I couldn't tell which ones they were.

The $199 price tag must be in the time it takes to assemble... which, with the proper tools shouldn't take too long at all. You've got a very profitable product there Dr. Tweak, as long as there is a demand for it.

[BloodyStupidDave...]

I was curious about the mark up on this so I did a little research. These are the part numbers and prices from Toyota:

The $199 price tag must be in the time it takes to assemble... which, with the proper tools shouldn't take too long at all. You've got a very profitable product there Dr. Tweak, as long as there is a demand for it.

Nearly all the connector housings are not available from Toyota. Many of the loom connector housings don't even have their own part numbers. Furthermore, while some of the pins are available from mouser and the like, the connector housings generally are not. They are only available from specialist parts distributors and then typically only in multiples of 3000 or so.

Given that the total market opportunity is so small, plus the assembly and testing time needed plus the likely parts wastage, $199 seems like a fair price.

This post has been edited by BloodyStupidDavey: Jan 2, 2008 - 4:38 AM