Right then, just went to have a quick go at reading the error codes the car holds via the paperclip method and it worked fine for me.

I found the details here:
[url="http://mkiv.supras.org.nz/techo.htm#ENGINE_CODES"]http://mkiv.supras.org.nz/techo.htm#ENGINE_CODES[/url]

Ensure the ignition is off, and pop the bonnet and open the diagnostic cap in front of the main ECU cover - you can't miss it.

Inside here are various pins and they are all labelled on the underneath of the cap you just opened.

You want to bridge Tc and E1 on the MK2 / VVTI (it's Te1 and E1 on the MK1 / none-VVTI).

Now go and turn on the ignition - you don't need to start the car.

At this point the satnav display if you have it will display the diagnostics for the audio system and trip computer, and the lights on the dash will be going off like a Christmas tree!

Focus on each light at a time and watch the pattern. If it's flashing continously, then that ECU has no errors to report, whereas if there is a specific pattern, it is telling you the codes.

Basically get a piece of paper and wait for the long pause - that is where it's starting again, and then note the numbers down, ie I just had the following from the VSC light:

flash flash flash flash flash pause flash flash flash flash long pause

That is a 54 code - can't find what it means though as never had any problems with it! So assuming it's an old error that I've never seen as I've just removed the EFI and ETCS fuses to reset the main ECU and the VSC and ARS systems retained their codes.

There will be a medium length pause in between each error code and a long pause right at the end before it starts listing them all again - while the ports are bridged it will keep repeating them indefinitely.

Likewise I got the following number out of the ARS system:

13425462

Not sure how the heck you're supposed to break that down - if it's four 2 digit errors or two 4 digit errors! I've only ever had the ARS light come on once and that was when coming out of one of these car parks that was a constant bend as you came down about 4 floors of building so it was a spiral. The ARS light lit then when I came out I stopped the engine and restarted and never had a problem with it again and it's been over a year since that happened!

Hopefully this should make it easier for any of you to read out any error codes from a MK2 anyway as it means you don't need to worry about finding a compatible OBD-II reader - just a paperclip or a piece of wire to bridge that connection and a pen and paper!

This method is used for all pre OBDII Toyota vehicles so this can also be used for the LS400s and GS300 Series I.

Nice, spotted an article about enabling test mode so you can get more codes out the car than normally so might have a look into that but they've removed one of the connectors from the VVTI so guess that only works on the older ones:

This is the one:

[url="http://www.bba-reman.com/auto-mine/toyota/toyota_obd.htm"]http://www.bba-reman.com/auto-mine/toyota/toyota_obd.htm[/url]

What do you reckon mate? Going to have a nosey and see if I can subsitute the missing Te1 connection with Tc if I have a Te2 on mine - if not that idea goes out the window

Just bouncing this as I'm sure Chris mentioned yesterday that this trick also works on the IS - not sure if it was the beer I'd had though but may be worth something for a lot of you to bear in mind if it does work!

yes you can do it for certain tests on the 1st generation IS - eg the ABS system

Ah right ok so it doesn't read the engine codes then - still useful for all the other ECUs though I guess!