So I did the 3.4 swap a couple of years ago but now it's having some issues and I'd like to pull live data. When I connect a basic ODB-II scanner it powers up and reports no codes which is good because the MIL light is not on. When I connect a more advanced scanner to pull live info it doesn't power up. Have to connect a USB cable to external power to turn it on. It goes through the connection process but reports it can't connect to the ECU. So looks like I've got an issue with wiring.

Anyone have any charts, pinout info, or advice for the ODB-II connector to a 99 Tacoma 4wd 5spd ECU wiring?

Tks!

 

Here ya go:

from a '98 but its the same.

 

Well it looks like I've got all 4 wires hooked up...

So ALL info basically comes down the SDL line?
I was thinking there may have been another wire for the 9141-2 protcol.

Thanks for the info.

 

The SIL carries the data from the ECU. Sounds like you aren't giving it +12v thru the "BATT" line? Also make sure you've got it grounded. I used a really expensive Snap On scanner on mine and all systems were online and showing live data.

 

make sure the OBD 2 plug wires are pinned correctly.

 

So the power line was only putting out 6.6v instead of 12v
Fixed that and the ODB-II scanner is working now.

Truck was really down on power and felt like it sometimes missed or had a plugged cat. Pulled the codes but none there stored or otherwise. Pulled live data and didn't see anything out of the ordinary.

Turns out it was ... a loose crank pully bolt. Wow...
Anyway, put in a NEW bolt. Torqued it up and it's running great now.