What is the reason for the Audi P223700 pump current open circuit fault?
1 Answers
It is due to the oxygen sensor positive current circuit/open circuit (Bank 1 Sensor 1). The specific details are as follows: 1. The role of the oxygen sensor: The oxygen sensor measures the oxygen content in the engine exhaust to adjust the fuel injection volume, thereby enabling the engine to achieve the optimal air-fuel ratio. In OBD fault codes, you often see references to which bank and which oxygen sensor. 2. Bank numbering: Bank 1 refers to the bank where cylinder 1 is located, and the remaining bank is Bank 2. Regardless of the bank, Sensor 1 always refers to the upstream oxygen sensor (before the catalytic converter), and Sensor 2 always refers to the downstream oxygen sensor (after the catalytic converter).