Wiring is probably the most daunting and cumbersome for most completing this conversion. If you do not know much about wiring or aren’t confident reading wiring diagrams then please have an auto electrician or workshop do the work for you.
At the time I spent a while reading the diagrams, looking at the differences and it probably took me a few weeks of studying and identifying what I needed to do, there could be small differences between year models and SZ/SZR so the information below is all on my experiences.
I’m going to give you the best advice here – Track down the end state engine loom and stock ECU, and this will save you countless hours of troubleshooting and won’t require too much custom wiring. If you track down a front body loom for the fuse box area then it should be all plug and play. There are so many variables to this step and this is the process I followed which worked for me, I was lucky enough to find a VVTi engine loom and ECU out of a supra.
The last step in all of the stock removal should have the engine loom out of the way and all of the connectors unplugged, ensure the GE engine is out and that the GTE is ready to have the loom installed (If required).
Also last thing – Please check the first page of this guide for links to all the wiring manuals, pinouts and parts required.
Below is a general guide to the custom wiring you will need to do
- Fuse box EFI1 / EFI2 wiring
- Fuse box ECTS-i wiring
- Potentially o2 sensor and water temp sender on engine wiring loom (On aristo engines)
- If you want the electric fan for the A/C you will need a 30amp FAN fuse with a relay/wiring – I decided against this
- If you want advanced ABS and traction control buttons you will need that wiring and ECU – I also decided against this
The GE and GTE share the same fuel pump ECU and fuel pump, the only difference is that the GE only has 1 EFI relay and the GTE has 2 EFI relays.