Was getting P0052 (B2S1 O2 heater ckt high). I would get the DTC when starting the engine cold. After the engine heats up I could clear the code manually or it would clear after a few start cycles. As long as the engine was warm the code would not reappear. Next day at cold start, the code would be back.
Changed the O2 sensor (OEM). Same problem.
I have checked the harness and continuity is good. Cleaned connectors on O2 sensor as well as PCM. Cold O2 heater resistance is good. 12V present and grounds are good.
When starting the engine cold both upstream O2 sensors start working at about the same time (around 20~30 seconds). This tells me that the heater is actually working and I am getting a false DTC from the PCM.

Any thoughts or ideas will be appreciated.

 

makesure u get the right o2 sensors i replaced the front of cat on passenger side and advance said they were all the same and they arnt. i dont remember the numbers. but i put one in the front and got the same code as u got plus random miss fires sometimes. i just took the ol o2 sensor and cleaned it with carb cleaner and a good scrub with a wire brush

 

its only coming on when your engine is cold because thats the only time the heater circuit comes into play. The 02 sensor has to heat up to about 600 degrees. Once the engine warms up it no longer has to heat up. If you replaced the sensor and still had the same problem, i am going to guess that you have a problem in the wiring for the heater circuit. Check the connector that goes into the sensor and look for corrosion or damaged on the pins

 

Thanks for the info.
I will get a chance to do some more troubleshooting in a few days and will post back.

 

Got a chance to dig a little deeper. O2 sensor plug pins 1&2 are for the heater. Pin 2 is ground. I am not getting voltage on pin 1 from the PCM which comes from the C2 connector pin 17. I have to remove the air filter box to get to the PCM connector so I can check continuity, but did not have time today. Will update with further findings.

 

Thought I would follow up.
I had not been too concerned since it was just the heater ckts that were not working. Once the exhaust system got hot enough the O2 sensors would come alive anyway.

Over time, all four O2 sensor heater circuits failed. Then, a few weeks ago, I started getting codes for Bank 1 and Bank 2 in open loop along with Banks 1 & 2 lean and rich at the same time. Truck would run and idle poorly.

I could not get the dealer to swap the PCM unless they replaced the O2 sensors that I had already replaced. And, of course, they wanted close to $500.00 for that.

Anyway, I ordered a PCM from All Computer Resources. It took care of all the issues and the truck runs great.

I tend to believe that the original PCM had some problems from day one since I don't remember the engine and transmission ever being as smooth as they are now.

 

Thanks for the update. I didn't notice the age of the post when I read the OP, and I was thinking PCM because I think I have heard of this before. Glad you got it figured out, that would have driven me crazy.