LS400tragic

Hi All, first time poster. I have the ECU out of my 1995 Ls 400 and Identified leaking capacitors. Not having the skills (or confidence) to replace the capacitors myself, I have given the job to a guy who specializes in Automotive ECU repairs, so I'm confident he knows what he is doing.
The repairer has identified a number of leaking capacitors and one in particular that has created an open circuit. Unfortunately he cannot locate a wiring diagram for the ECU or identify the pin outs. I have tried searching the forum for this information but impatience has got the better of me. Can you please point me towards an ECU wiring diagram in English (sorry we don't speak or read Japanese) that identifies the function of each circuit and the pin outputs for the 1UZ - FE ECU please.

While I'm here, The reason I'm looking at the ECU is to eliminate it as the cause of an extremely rich over fueling problem on the RH bank. Unburnt fuel dripping from the exhaust!! If replacing the capacitors and repairing the ECU does not fix it, my next move is to see if it has a faulty injector (stuck open ) on number 8 cylinder. The vehicle has just over 300,000 klm and the injectors have never been touched. Has anyone else had a similar experience?

paulo57509

The only place where I know you can get pin-out information (from a trusted site) is here:

https://techinfo.toyota.com/

A standard 2-day subscription ($25) is enough time to find the wiring diagrams for your model year and download them. Be aware that once you pay your subscription, it can take 1-3 days for it to become active. The subscription part of the process is handled by Snap-On. don't be alarmed; it works.

You're NOT going to find PC board traces, etc.

LS400tragic

Thanks Paulo57509, I'll pass this on to my guy and see what he says. I appreciate you help.

Yamae

JFYI. Those 8 transistors for the injector drive are located at the top left corner in this photo.
The Collector-Emitter short or the constant Base drive causes the stuck open problem of the injector. You can check this observing the waveform using an oscilloscope. A good injector drive waveform should be like this in this post.

LS400tragic

Thank you Yamae, that's encouraging information. The tech I have working on the ECU is aware of those 8 transistors, and their relationship to the injectors, but his main problem is confirming the faults and testing the unit.

Do you have a copy of a diagram of the pin outs? or an ECU circuit diagram? I believe the specific model is relevant, mine is a UCF20R - AEPGKQ.
Thanks in advance.

Yamae

I only have a wiring diagram for JDM Celsiors UCF20 and UCF21 which are printed in Japanese. Toyota/Lexus/Denso releases wiring diagrams but never releases circuit diagrams and you need to do the reverse engineering to analyze how circuits are designed and organized. It needs good skills and equipments such as an Xray machine and others. I only have done just some just for my curiosity to help local shop owners and dealer managers.