How do you bypass a bad PCM on a 91.5 with auto trans to go into overdrive?

 

Ground the wire that's NOT blue.

 

on my 93 first gen with auto trans, so far after the pcm went bad I got the speedo working by grounding the speed sensor ground wire and running a power wire with a resistor inline to the brown and tan 8 volt feed wire near the pcm plug to the speed sensor and also goes to the crank sensor.speedo works. I took care of the not charging problem with a separate wire directly from alternator to the battery and used an external voltage regulator with the power to the regulator on it's own relay. I also have the o/d on a switch and am going to use a pressure switch on the trans so I can also have it go into o/d automaticaly. I am still working on the tach hook up.