Lexus IS300 ECU Pinouts

Someone had asked for these and I tracked them down, attached are both the ECU pinouts for the 2001 and also 2002-2005 Lexus IS300.

Disclaimer – I don’t take any responsibility for these diagrams, these do seem to be the factory pinout diagrams but I always like to double check / cross reference any wiring. Also I do not own a IS300 and can’t confirm these ECU pinouts.


Wiring Diagrams can be found here –

2JZGTE VVTi OBD Scanning and Information

While I had a stock engine and ECU I really strugged to find much information or tools to scan the 2JZGTE VVTi engine in my supra, standard OBDII tools did not seem to work. Some guys had tried and failed or got mixed results. I did find a guy in the UK that found out how, but it seemed one of his friends was a Toyota Mechanic and had access to an expensive scanner tool which wasn’t an option for me.

I’ve hopefully now found some basic information for the Toyota Supra 2JZGTE VVTi ECU;

-Is not OBDII compliant, it uses an JOBD compliant protocol as it’s a Japanese ECU –
-Uses a OBDII connector but requires a scan tool with correct software to read the correct protocol which is ISO 14230

It now seems like there is a cheap solution for reading the protocol; Thanks to Muzzytt on and Konrad on for sharing this information around on the forums.


2JZGTE VVTi Aftermarket Support

There isn’t too much different between the 2JZGTE VVTi and 2JZGTE non-vvti but  there are some parts that are different and things you need to check before modifying, upgrading or starting a new project. Below are some parts and vendors that are compatiable or make parts specifically for the 2JZGTE VVTi for aftermarket support.

Check out my other post regarding 2JZGTE VVTi engines for any more specifc information about the engine –


Using the IGF pin as an RPM output

One thing I’ve been meaning to fix up is my apexi RSM since going single turbo and aftermarket ViPEC V88 ECU.

I used to splice the Apexi RSM RPM wire to the IGF wire on the stock loom as per the Apexi Manual, this gave me a RPM reading on the Apexi RSM without any issues.

The stock 2JZGTE ECU uses a IGT and IGF ignition signal – basically the IGT sends signals from ECU to igniter and IGF sends ignition verification signals from igniter to the ECU – to confirm ignition spark which allows the ECU to enter fail-safe or limp-mode if there is a problem. There is a good writeup here on how the whole system works for different Toyota ignition types for more technical info –

The ViPEC (and most other EMU’s) don’t need the IGF wire function, so it’s not plugged into anything usually.

Now with the ViPEC in and no stock ECU I hooked the IGF wire directly to the Apexi RSM (Not plugged into ViPEC at all). I’m  now getting an RPM signal on the Apexi RSM, so anyone wanting to use the signal for RPM can if their tacho device uses the stock IGF signal location.