I'm after getting a diagnostic tool or cable to laptop with software to check engine and maybe play with other stuff in the car. First, this is the Celsior that was released in Japan in 89. I have discovered that the data connector/diagnosis thing is different to the Lexus 90-94.
Here is a pic of that I have under the dash (now that I've finally found it - thanks for the help with that guys).

Now, looking around on the web I can see all sorts of cheap cables that say they are OBDII (and a few other things) to USB that come with PC software to clear error codes, see realtime data, change behavior of the car in many many ways. Sounds really good but they come with a different connector to what I have.
A little more research and it looks like that connector in my car (above pic) is a short version of the OBDI (OBD 1) interface. I seem to have found something on ebay thats a OBDI to OBDII (17 pin to 16 pin) converter. So, if I get the OBD1 to OBD2 converter, then a OBD2 to USB PC interface with PC software "Toyota Techstream Diagnostic / Customization software".
OBD1 to OBD2: https://www.ebay.com/itm/17-Pin-OBD1...-/263469375092
OBD2 to PC + Software: https://shoppingcart.aliexpress.com/...99999.90000003
Does this seem reasonable, or am I expecting too much or missing something?
TBH, its not too big an investment to just try as I'm probably the only one here with an actual Japanese 89 Celsior. I have no idea and cant seem to find out if the Later exported Celsior LS400's had OBD1 or OBD2 Connectors.

Or is there something else I should be looking at?
Are these cheap efforts worth the trouble?

 

It used be only sold for authorized dealers by Toyota. I once found a used one at the Yahoo Auction but no more these days. It was still expensive though.

 

This is it. トヨタダイアグ・・・・　means Toyota diagnosis reader set.
As you see there are 2 different connectors.

 

Bugger! I'll still keep an eye out for one. Thanks for the info.
I wonder if the standard ones they use in normal workshops will work. I have a mate who works at a service centre (not a dealership).
He now lives about 200 miles away but I'll be taking the car for a run in about 2 weeks, so I'll call in on him and see.
Been meaning to catch up with him for a few years now.

 

Is that a pinout on the underside of the cover/cap? Could one put a jumper to the diagnostic wire and have it blink out codes with the CEL? Does the JDM ECU even do that?

 

Yes, the pinout is shown on the underside of the cap. Its exactly the same pinout as the plug on the engine.
I would imagine that the engine plug only deals with the engine settings/data and the internal one only deals with Lock timing, windows, airbag(s) and other more internal settings.
Otherwise why have two?
As for the flash codes, no idea. hopefully someone will know.

 

Apparently it can blink out error codes, but mine either does not, or it has no error codes to report. Too good to be true? Will have to unplug the air flow meter while the engine is running just to see if it then flashes out the appropriate error code.
Apparently both plugs (engine bay and drivers side interior) offer exactly the same functionality.
On the off chance it would work, I purchased one of them cheepo ELM327 bluetooth OBDII interfaces.
I have read that people say that they have had issues with dropping BT connection, but I decided to take a chance (only a few bucks anyway). Also purchased a OBD I to OBD II cable. Arrived today. I can make a BT connection to the ELM327 no problem (and it appears stable), but the Torque software states that while it is connected to the ELM327, the ELM327 is not connected to the ECU.
Maybe its just the cheepo ELM327, or I have read that there are some caps that often need replacing on the ECU that stop it form talking to external devices through the OBD port
Can anyone shed some light on these caps on the ECU? and if thats likely to be the problem? Anyone know the number and value of the caps?

Thanks.