P0041 indicates that the powertrain control module has detected that the oxygen sensor signals from Bank 1 Sensor 2 and Bank 2 Sensor 2 are swapped. The ECM expects each sensor's voltage signal to correspond to a specific bank, and when the signals are interchanged it sets this code. The issue is usually related to wiring or connector routing rather than a faulty sensor or PCM.
The most common cause is that the electrical connectors for Bank 1 Sensor 2 and Bank 2 Sensor 2 have been interchanged during service or manufacturing, causing the ECM to receive the wrong signal from each bank.
Insulation wear, rodent damage, or improperly secured harnesses can allow the signal wires of the two sensors to touch or short together, leading the PCM to interpret them as swapped.
Although less frequent, one of the sensors may have an internal fault that produces a voltage pattern the ECM interprets as belonging to the opposite bank, especially if the other sensor is functioning normally.
If a sensor was mistakenly installed in the wrong bank's location during a repair, the ECM will see the signal from the opposite bank and set P0041.
A rare internal fault in the PCM's O2 sensor input circuitry could misinterpret which bank a signal originates from. This is considered only after wiring and sensors have been ruled out.
No. The powertrain control module is rarely the cause of this code. Most cases are due to swapped or damaged wiring/connectors, and replacing the PCM usually does not resolve the issue.
Swapping the sensors can be a useful diagnostic step: if the code moves to the other bank after swapping, the wiring is likely correct and a sensor may be faulty. If the code stays on the same bank, the problem is probably in the wiring or connectors.
Clearing the code only turns off the Check Engine Light temporarily. If the underlying wiring or sensor issue is not corrected, the code will return once the ECM runs its self‑test again.