Hi Jimmy,
It could be a few different things causing this. Yes, the PCM could be the cause, but other things can cause it as well. For example, if the ignition switch is faulty and only supplies a signal for ignition in the start position. An issue with the fuel pump or ignition system can do this as well.
So, here is where we need to start. First, why doesn't the scan tool connect? If you look at the pic below, check pin 16 (highlighted with yellow) for B+ voltage. If that is good, confirm pins 4 and 5 have continuity to ground. Note: If there is no continuity, try it with the key in the on position/engine off.
The last two pics are of the computer data lines. Note Fuse 11 in the interior fuse box which is for the cigarette lighter as well as powering pin 16 on the DLC, needs to be checked (see last pic for location). In addition to checking the fuse, make sure there is power to and from it.
Here is a link you may find helpful:
https://www.2carpros.com/articles/how-to-check-a-car-fuse
Let me know what you find.
Take care,
Joe
See pics below.
Images (Click to make bigger)
SPONSORED LINKS
Monday, October 17th, 2022 AT 6:41 PM