I have a check engine light on in my 89 4runner and I searched and found how to jump the diagnostic terminals on an 94 but it seems to be different on my 89. So how do I check the codes on this old pig?

 

You may have a separate diagnostic plug on the driver's side near the inner fender. It's round ,not square like the newer models. My 92 has the square diagnosis port on the passenger side, but I have seen posts on here that describe a round port on older models.

Mike in AR