P0060 indicates that the powertrain control module has detected an abnormal resistance in the heater circuit of the downstream heated oxygen sensor (Bank 2, Sensor 2). The heater brings the sensor to operating temperature quickly; if its resistance is out of range, the sensor cannot provide accurate exhaust data for catalyst monitoring.
The internal heater coil opens or shorts, causing resistance to fall outside the calibrated range.
Damaged, corroded, or loose connectors and harnesses increase circuit resistance.
Loss of voltage to the heater prevents it from reaching the expected resistance.
Outside air entering the exhaust stream can affect sensor temperature and heater control logic.
Internal driver damage is rare but possible; it would be considered only after all wiring and sensor tests pass.
PCM failure is an extremely rare cause of P0060. The code is almost always due to the sensor heater, wiring, or a fuse/relay. Replace the PCM only after all other components have been verified.
The vehicle will typically run, but fuel economy may suffer and the vehicle will not pass an emissions test. Extended operation with a failed heater can shorten catalyst life.
Sensor 2 is the downstream (post-catalyst) oxygen sensor on Bank 2.
The PCM monitors heater current or resistance continuously; a fault usually sets the code within one or two drive cycles once the heater is commanded on.