I am unable to get my '98 Tacoma 2.7l to pass inspection because the onboard diagnostic computer will not communicate with the inspection machine. I have tried more than one shop and the answer is the same. All the fuses have been checked and are ok. Any ideas on what could cause this? Thanks..
I had the same problem on my 1997 Toyota Corolla. Search the group for "1997 OBD Corolla" and you'll find the thread.
Ray posted some very useful information on how to test the OBD-II port using a multimeter. My problem was ended up being simple to fix. I decided to trace the harness and as I took off the kick-panel under the steering column, I found that one end of the harness that connected to the OBD-II port was unplugged. I plugged it back in and the port worked as expected. Since you have already checked the fuses, I would start tracing the harness back from the port.
Cheers, Nirav
FYI: I dug up the thread:
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Check the connector for the wire harness under the dash for the OBD connector to make sure it is tight.
I'm not sure. But I would cast my doubts on the computer itself.
The computer is the LAST thing I would check on a Toyota. I've looked at a lot of problem cars that dealerships had problems fixing and have never seen a bad computer. The place that inspects warranty computer returns reports that only around 1 every other year actually turns out to be bad. All the other replacements were unnecessary.
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