P0040

DTC P0040, sometimes indicated as P004000 is an OBD diagnostic trouble code indicating a generic fault with the vehicle powertrain (i.e. engine and gearbox). This code identifies an error with the air/fuel mixture causing upstream oxygen sensors swapped from bank to bank.

The upstream oxygen sensors are swapped from bank to bank.

• P0040: Upstream Oxygen Sensors Swapped From Bank To Bank
• P0040: O2 Sensor Signals Swapped Bank 1 Sensor 1/Bank 2 Sensor 1
• P0040: O2 Bank 1 Sensor 1 Signals Swapped w/ O2 Bank 2 Sensor 1
• P0040: Oxygen sensor signals swapped, bank 1 sensor 1/bank 2 sensor 1
• P0040 00: Oxygen sensor signals swapped, bank 1 sensor 1/bank 2 sensor 1