Description of OBD-II DTC Trouble Code
The O2 Sensor Signals have been Swapped between Bank 1 Sensor 2 and Bank 2 Sensor 2.
What is the meaning of this?
This diagnostic trouble code (DTC) is a generic OBD-II powertrain code. It is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may vary depending on the make and model. Owners of these brands, including but not limited to BMW, Dodge, Ford, Chrysler, Audi, VW, Mazda, Jeep, etc., may experience this issue.
In simple terms, a P0041 code indicates that the vehicle’s computer (the PCM or powertrain control module) has detected that the wiring of the O2 oxygen sensors downstream from the catalytic converter has been swapped.
The vehicle’s PCM uses readings from multiple oxygen sensors to adjust the amount of fuel injected into the engine for optimal operation. If, for example, it injects more fuel into bank 2 of the engine but detects a reaction from the bank 1 oxygen sensor instead of bank 2, it triggers this code. In this DTC, the #2 O2 oxygen sensor will be located downstream from the catalytic converter. It is also possible to experience the P0040 DTC simultaneously.
This code is uncommon and only applies to vehicles with engines that have more than one bank of cylinders. Bank 1 always refers to the bank of the engine that contains cylinder #1.
Symptoms
The symptoms of a P0041 engine code may include:
Causes
A P0041 DTC trouble code may be caused by one or more of the following:
Possible Solutions
A good first step is to determine if any recent work has been done in the area of the exhaust and O2 sensors. If so, there is a high probability that the issue is caused by swapped wiring connectors for the second O2 sensor from bank 1 to bank 2.
Visually inspect all wiring and connectors leading to the second O2 sensors (which are likely located behind/downstream from the catalytic converters). Check if the wires are intact and not burned or twisted, etc. It is highly likely that the connectors are swapped. If you are a DIY enthusiast, you can even try swapping these two oxygen wiring connectors as an initial repair step. Then, clear the trouble codes and road test the vehicle to see if the code reappears. If it does not, then the swapped connectors were most likely the problem.
The next step would be to closely inspect the O2 wiring and connectors at the PCM end. Ensure that the wires are in the correct pin locations going into the PCM and its harness (refer to a vehicle-specific repair manual for guidance). Be aware of any swapped wires or damaged wires, and repair them as necessary.
If needed, perform a continuity test on each individual wire from the PCM to the O2 sensor and repair any issues found.
If you have access to an advanced scan tool, use it to monitor (graph) the O2 sensor readings and compare them to specifications. PCM failure should be considered as a last resort and may require the assistance of a qualified technician for repair or replacement.
Other related DTCs: P0040
