2006 Toyota Tacoma with a 4.0L engine. Code in memory was P0158 B2 sensor 2 circuit high. I pulled up the PIDs for both rear o2s and they were 0.00v with the engine running. I then held the rpm at about 3000 and they began to show activity. I took a measurement on the power and ground on both of the rear o2s. I found 12v on both wires on each o2. I then went to the PCM and probed the control wire. It was a solid 12v (this is with a DSO) I cleared the code and tested again. Still no control. All powers and grounds on the computer tested and in spec. other test I did was ohm the heater and got 13.5 on both.
Am I missing anything? The only inputs for the heater I read about on Mitchell is engine running and battery 10.5v or more. I know it enters fail safe when a fault is detected so I cleared the code and had the same results. I also pulled the negative cable to clear the memory as well.
Recent repairs are power steering rack and timing cover gasket.
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