I have been messing with my MR2 for a few years now, but what holds back my dreams is the factory engine management, or more importantly the option to mess with the original engine management without going standalone. This first world problem has kept me awake at night for quite some time now.
My MR2 has the ECU part number 89661-17730 on the box and inside it contains the cpu 151815-5431 97CW42AF-3448.
Which is a LQFP120 Toshiba TLCS-900 series, with 128k ROM and 6k RAM, and unfortunately it is a Masked ROM so no reflashing is possible.
I have bought a few different standard ecu's from different global markets, but they all have the same chip. Too many hours I've wasted on finding a solution to this problem, it is unfeasible to develop a daughter board for this original ECU, although possible as it has been done by some of the Japanese big name tuning companies.
Anyway, I have found an ECU from a USA spec corolla ZZE130, which very handily comes with the 1zz-fe engine too, but it has a wildly different ECU. The part number I have is a 89666-02140, and the best bit is, it is based on a Hitachi 76F0004 microprocessor, which can be easily re flashed with some widely available tools thought the OBD2 port on the K line. It can even be "updated" with techstream, but other aftermarket tools include PCMflash with "Module 35" which also does checksum correction too, and there are many others that support this ECU.
Now I have mapped out all the pinouts for both the original MR2 ecu, and the ZZE130 ecu, and it all looks pretty compatible, except for some of the dashboard functions like the temp gauge, and the knock sensor.
So my next step is to build a conversion harness from the connector from a spare MR2 ecu, and the plugs from a ZZE130 corolla, and give this idea a shot to see if it will even run on it firstly, then start mapping out the fuel and ignition tables.
I'm putting this post out there to see if anyone else fancies coming along for the journey? Does this sound like something that would float your boat?
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