ok so after battleing for 4 months and on/off, i can not get rid of my O2 sensor Heater circute code! i have checked all of the wiring and replaced both sensors 3 times! and yes i even cleared the code countless of times. Im dang positive that i need another PCM. but where oh where shall i find one?? (dealer being last resort....$$$$$$) 02 5.9 only one cat

 

Are using OEM replacement O2 sensor or generic, I have had issues with generic O2 sensors in the past? What is the code its throwing, Are you sure it is a heater code? To test the 02 sensor itself the resistance should be 13 ohms at around 70 degrees. Have you checked Fuse 49? It should be a 20amp fuse, This actually provides power to both sensors.

However you are correct, The 02 sensor heater is controlled directly via a PWM in the PCM.

 

i do have OEM sensors and i have checked the fuse, i even changed it.

 

www.solopcms.com is where i got a new PCM for my 5.9 durango. they were awesome to do business with

 

You can read the resistance of the pins on the 02-sensor before spending money on replacements just so you know.
Also, i would pull off your IAT sensor and clean it using electrical cleaner and look into your coolant sensors and make sure BOTH are working. There is one that feeds the dash and one that feeds the pcm. The pcm monitors engine coolant temp and IAT temp which will depend on how the pcm reacts against the 02 heater circuit..code or no code.

Is your truck running rich? Poor gas mileage? if not then your sensor is working fine.