This code indicates an electrical short between the signal and heater circuits within the downstream oxygen sensor on engine bank 2. The powertrain control module detects abnormal voltage resistance that prevents accurate monitoring of the catalytic converter. This fault is typically caused by damaged wiring or internal sensor failure rather than a computer malfunction.
Heat exposure often melts insulation, causing signal and heater wires to touch.
The heating element inside the sensor may break down and contact the signal circuit.
Moisture intrusion in the sensor plug can bridge separate circuit terminals.
Wiring may rub against brackets or the engine block, exposing copper strands.
Chewed insulation near the sensor can cause unintended circuit connections.
Internal controller failure is extremely rare and should only be considered after all wiring and sensors are verified.
No, this code is almost never caused by a faulty PCM and usually indicates wiring or sensor issues.
The vehicle is generally safe to drive, but fuel economy may drop and it will fail emissions inspections.
Bank 2 is the engine side without cylinder 1, and Sensor 2 is the downstream oxygen sensor after the catalytic converter.
No, inspect the wiring first because heat damage to the harness is a very common cause for this specific short circuit.