[rlenglish]

Hello nottoday. Maybe your anger insulted the parts person. I just put a new pcm in a 2008. They come blank and the dealer has to program them.

 

[rlenglish]

Yes the voltage for the O2 heaters run through the PCM. With most vehicles it is a ASD power supply then the PCM controls the heater off and on. It has to run through the PCM so it can be monitored for emissions. We heat the O2's to get them working sooner.
With the JK's the problem was when the ASD relay stuck on it would overheat the board in the PCM and damage it. The vehicle would run fine but would have heater codes for all 4 O2's.
There is no perfect system and the Manufactures are always walking the fine line between cost and durability.

 

[rlenglish]

I don't know how the pcm gets power for the heaters. Your TJ has ignition switched power and relay supplied power. The heaters themselves won't cause it not to run but a power supply problem would. Have a good look at your relays. For the price of them I would change them, or at least move them around. See if the problem changes?

 

[rlenglish]

Early JK's have this problem and it usually turns out to be the driver in the pcm. Being that your's is a TJ and the codes went away I would guess that you have a wiring problem. The heater circuits usually get separate feeds from the pcm but If I remember correct they share a ground circuit with a lot of other stuff. I would start with your ground wires, wherever you can find them, fender, firewall, battery. As with older vehicles don't be afraid to run a couple extra grounds. From the frame to the body and engine.