Originally Posted by Wheelman
you dont need a tool just jump the two terminals next to each other on the obd port with a wire or paper clip. Then turn the key on and off 3 time the last time leaving it in the on position the last time. Then count the flashes on the check engine light. It will blink a few time then pause then blink again. Like Blink,Blink, Pause Blink,Blink,Blink and that would be 23. It will repeat the code 3 times.
you jump two terminals on GM, you cycle the key for Chrysler. The two are completely different and not used together.