I understand that I can "jump" the TE1 and E1 diagnostic terminals on my 94 4Runner (3VZE) so that I can get the Check Engine light code, but the terminals are caked full of electrical grease so I cannot see what the inside looks like to determine what gauge of wire to use.

I tired using some 12 gauge copper wire, but when the ignition is turned to ON, the Check Engine light comes on and stays solid with the remainder of the lights under the dash. I don't want to push the wire down too hard and damage the terminals.

What is the proper way to jump these terminals?

 

paperclip will do fine (12 gauge is probably too big).

Leave the electrical grease there. It doesn't provide a lot of protection, but it's better than nothing.

 

Got it to work with a paper clip, thanks!