my computer isnt talking to the OBDii tester, it is in a 90 with a 96 tacoma engine, harness, and computer. the first go-around I wired it all correctly as far as I can see, I have bent the pins so that they will have full contact with the connectors. I am using pins 2, 4, 5, and 16

"pin 2" runs to pin 19E on the ECU, with shielding running all the way from the OBD connector til about 3" away from the ECU (would that uninsulated 3" matter?) the shielding splices into a wire that was 22IK2 on the Taco (goes to drivers side intake manifold ground)

pin 4 runs to the circuit open relay ground (i may have just grounded it, I need to go out and double check, but it shouldn't matter ...maybe it does)

pin 5 is also grounded to the drivers side intake manifold ground

pin 16 goes to some power source ...does it matter where it goes? I am under the assumption that as long as it is +12 it should work.

the truck runs awesome (10k miles on the swap with NO issues), I don't have a 2nd O2 sensor on it, but I built a fooler, maybe it isn't working? anyway I would just like to be able to read codes to see what it is.

 

Is there anybody out there...



it just doesn't make sense, I believe I have everything hooked up right and it isnt working.

 

man Ryan I was just reading something similar to this in another thread but I didnt read it really close but just scanned it. Lemme see if I can find it and i'll post the link. It may turn out that it was something totally different but I'll try.

Obviously the basics, you ohmed out your wire and they are good, ohmed your grounds, etc.

 

LOL....nevermind. Found it but i see YOU posted in that thread.....so i guess that didnt help.

Sorry i couldnt help

 

do you have the key to the on position? the position right be for you start the truck.

 

haha thanks guys ...yes the key is in the "on" position, I tested the tester out on my cummins and it does work, so IDK what the deal is, yes, i used a multi-meter with the grounds, even ran an extended wire to the driver side intake manifold for the multimeter to get an accurate reading as to where wires are supposed to be grounded. It is baffling me. Any other suggestions?

 

Im having the same problem with no results. My reader just says that there is a circuit malfunction on everything so it cant read them....runs like a CHAMP.

I tried a bunch of different grounds and powers, all with the same result.

 

Maybe it's as simple as trying another OBDii tester? IDK ...I've been keeping the vatozone loaner tester on hand in case someone has an idea, haha

 

Your wiring is all correct EXCEPT for pin 2. It should go to pin 7 on the OBD II port. Also, the power source should have constant power, not just switched power. This is how I did it and it scans just fine. Good luck.

 

I am having the same issue as the OP.

Only difference is it is connected to pin7, not pin 2.
I am not sure what is going on.

 

Edit:

So..

I have on the obd2 port. plugs 4,5,7,16 in use.
wire 16 is going to the fusebox to a 10amp fuse, for the turn signals i think, but should have constant power right?

Wire 4 and 5 are grounds i believe. One is to the COR relay ground, and the other is to some ground that is for the OBD2 connector.

and pin number 7 is going to plug 8A on the ecu.

The scanner is saying "error 1" and the booklet tells me that it means that the scanner is not communicating with the computer.

I am not sure what is going on. does anyone have any ideas?

 

for the OP, VWrunner is correct.

904runner, no, the blinker fuse does not have content power. that may be your problem.

 

Thank you.

I will swap it later today and see if that is the issue.
I just figured any power source would do.

 

Have you figured your issue out yet? I see that you have a 96 ecu. In 96 and 97 Toyota did not use the ISO protocal. They used the GM vpw or vpm(can't remember which now). You will need to get a scanner that supports this. I had the same issue as I have a 97 engine and ecu. I got the elm5 scanner online for 50 bucks that connects to a usb port on a laptop/computer. It works great.

 

I never figured out my problem. could not get it to work at all actually.

 

Drive up to Eugene oregon I'll test it for ya. If the wiring is correct, I can almost guarantee this is why its not working hehe. Isn't Chico in northern cali?

 

Well im not sure if it was wired correctly, i thought i had done so but i ended up pulling it out for the time being.

And as far as the scanner not working. i know for a fact that it did work on the 99 4runner at our house, and since my motor is from a 99 tacoma i figured it should have worked as well. I bet it jsut wasn't wired correctly.

 

2 of the wires are grounds 1 is power and 1 is signal. I tied into the ignition fuse for power. Also the signal wire i believe is shielded... so make sure the inner wire isnt' contacting the shield wrap.

 

so does the two grounds matter where they are connected.
here is a simple layout of what toyota wants.

I'm getting a P1600 ECM BATT Malfunction
But i'm not hooked up to 12v constant...on the obd2 port... could be an issue

 

yes you need constant, and it does not matter where the two ground. I have both together to one ground and for power i spliced in the the EFI .... It works