90 Prado Diagnosis/OBDII

[Bushy6728 Lurker Find all posts View Profile Close Bushy6728]

@ floating kiwi... Your right OBD2 is for 06 and newer, with several older protocols before consolidation. I read somewhere that 90 series have the older OBD1 plug with less pins (12 I think they said from Mem ) there are change over plugs for sale on flee bay, OBD1 to 0BD2 heres a link
OBD1 to OBD2 adapter cable 12-pin plug to 16-pin socket suit ford and chev
https://www.ebay.com.au/itm/13382604...YAAOSwpy9hKFxf

and heres another link of an OBD1 TO OBD2 CONVERTER with 22 pins on OBD1 and 16 on OBD2
22 Pin OBD1 To 16 Pin OBD2 Convertor Adapter Cable For TOYOTA Diagnostic Scanner
DO a search as this link is longer than the nullarbor

I am new to this fly by wires, have had lots of toyos with in line and rotary pumps dating back to when they had hand primers on the front of the pump. If you could light a smoke of a glow plug then it was worth putting back in, and crack an injector return to see if you had fuel, or the cam shaft was still turning and away it went . The only thing i know about technology is its GREAT when working and can be life threatening when not .

Was driving an oldy ,the other day a real roughy,from 1969 with a 3 speed box, no P/S a custom built troopy type for PMG/now TELSTRA. Had the pull stop cable in the middle of the dash ,, no electric fuel solenoid, a pull wind out hand throttle, as speed control and reverse turn of key for glow plugs.. but it did have a Mechanical pto winch , yep a real winch that would pull the bends outa the Murray. No remote cable to loose, no water ingress, worked when you wanted it

Wow what an reinactment , shot VAC BOOSTER ,soot and smoke coming up through the holes in the floor and a shot muffler. ,macho man s dream.Was an old fire truck with one tonne water, took 440m to get into top gear and same lenght to stop. WATER slopping outa the tank was the A/C. Got out after a few K's around the boundary fence fire breaks and knees and legs felt like I had been in the Gym too long .ahh the oldies , a walk down memory lane

In hind sight, the 20/20 vision I dont mind the older methods and spray testing injector pattern onto an A4 sheet with a bit of beetroot juice in the diesel. My ancient and incredibly trusty LN 05 Hilux has only one (1) important wire and thats to the fuel pump cut out. Always carry a jumper lead incase the wires get ripped off in the bush,(had it happen) and just hook it direct to positive terminal and listen for the click.

all this high tech is fine but with the fly by wires i am always happy to get back home each time as there is SFA one can do in the bush if they dont start . The only thing you can check in all honesty once the hood is open is oil and coolant levels. anything else needs an OBD2 . Breaking down on the highway with reception is one thing but in the bush when your tracks are the only , no reception, and a long walk home I like something I know and can fix

took a brand new 2000km,79 series double header tray back down the wapet line into the canning basin . needed a tow home ALL BECAUSE the long range tank swap over plug had been ever so slighty dislodged when they fitted the tow bar wiring .. nothing is certain , not even with a brand new unit . but then again thats the adventure of getting there and back. CRAWLED around under it on the burning hot sand looking for loose or ripped off wires (as V8's are famous for a crappy underbelly harness ) cursing slanties and wishing i had taken something else from the yard. maybe thats what "running in 'means ....

[Esses Junior Member Find all posts View Profile Close Esses]

i have a 90series prado vzj95r and it has what I think is an access point for OBDII situated on the right hand side of the motor.see pics.
[ATTACH=CONFIG]22028[/ATTACH]

This is the older OBD1 port. I recently bought an adaptor for it to my OBD2 Code-Reader ($16.00 from China) to see if that would work. It does fire up the OBD2 & starts to load, but then sticks half-way & won't go any further. I'll have to check for that other port under the dash.

[96VZJ95 Lurker Find all posts View Profile Close 96VZJ95]

See the post regarding Prado OBD1 here: https://www.pradopoint.com.au/forum/...i-tdcl-vs-mobd

A Toyota OBD1 to OBD2 cable will not enable an OBD2 scanner to read. The scanner must be OBD1 capable.

I bought a cheap old American 2nd hand OBD1/2 scanner (OTC 3499) to look at the high idle on my 1996 VZJ95.
Unfortunately it did not have the OTC Toyota cable and all US 1996 vehicles are OBD2 so the 5VZ-FE was not available in the scanner library for the OBD1 cable.
So I bought a Toyota 22 pin OBD1 to 16 pin OBD2 cable to hook it up and dialed up the 1993 Camry 3.0 which was in the scanner library. It would not talk until I put a jumper from E1 to TE2 in the connector pins. Then I could read 14 parameters live.
All parameters looked good except for the temperature sender which was zero degrees. I suspected an open circuit or failed sender.
I measured 550 Ohm across the temperature sender with the coolant around 70 degrees which looked OK and there are no error codes flashing (which should happen for an open or shorted sender) so now I suspect the meter is just not reading temperature. I would be surprised if Toyota used a different sender than the 3.0 V6.

I am now going to make a cable to a 9 pin D connector and then to a PC via a USB converter as in the link above and run the "Cartester 8000" software to see if it can read temperature.

I still have not found the cause of my high idle, although I manually jammed the ISC valve fully closed to make the car idle at 900 rpm hot (or 700 rpm with aircon). I was hoping that it would be a faulty temperature sender, or maybe I might see lean O2 sensors which would suggest an air leak.

Cheers,
Rob

[96VZJ95 Lurker Find all posts View Profile Close 96VZJ95]

The DIY cable and free software worked first time on my laptop. I can see 14 parameters live updated.

The temperature sensor works OK and ISCV is at 35% when warm so now I seem to be chasing an air leak as the O2 sensors indicate lean running with the high idle.

UPDATE:
The throttle body butterfly shaft had a few mm of up/down movement when held open. Consequently this is an air leak source.
I changed to a 2001 body from the wreckers and now it idles at 1300 rpm cold and 700 rpm hot.