Hey scotty, been curious about this weird H02S o2 heater circuit engine code ive been getting. Car is a 2011 mustang gt, mt82 manual, 115k miles. I recently did the clutch, and ever since then ive been fighting an H02S heater circuit code for my passenger upstream 02 sensor. However, ive also got P064D and P1646. P064D is an internal circuit short in the pcm. Engine light will go out on its own and then come back intermittently. Car will run horribly, and then next minute be fine. No crazy change in gas mileage. But when it decides to run right theres a noticeable difference in power and driveability. Could unplugging the battery for my clutch for a few days have fried my pcm? Maybe some fluid got on one of the connectors? I have a code reader but i cannot scan the vehicle with a more sophisticated tool. And being in the military i dont usually have time in my schedule between work and errands to have it checked i pretty much always need to get around. Any help would be much appreciated. Also, i replaced a fuse, and have been trying to diagnose for awhile
Well you obviously have some type of electronic problem check all the wiring using an all-meter or pay a mechanic who's a good electrical worker to check it out and if it's not in that odds are the computer driver circuits are damaged
You're going to want a mechanic to handle this one.
It is possible the PCM has an issue, but in my experience it's more likely to be a loose ground or short in a wiring loom somewhere. Issues like that are hard to give advice on because you really need to physically be able to test the wiring and see what is on the fritz.
Worst case, the PCM will need replacement.
