What is the reason for the Audi P223700 pump current open circuit fault?
2 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).
I've encountered quite a few Audi cars with this P223700 code issue, mostly caused by interrupted pump current, likely due to aged or worn wiring. From my garage experience, this frequently happens to vehicles that have been driven for many years or on rough roads – things like corroded wire terminals, loose connectors, or rodent-chewed cables can all disrupt the current. Blown fuses are another possibility; proper diagnosis requires a multimeter for resistance testing, and without professional tools, it's best not to tinker. Another common culprit is pump failure itself, with short-circuited or burnt motor windings, especially during cold winter starts. Occasionally, control module malfunctions (like ECU signal errors) may falsely indicate circuit breaks. Bottom line: don't underestimate this – if the pump fails while driving, it cripples the fuel or cooling system, potentially leaving you stranded. My advice? Get it professionally inspected at an authorized shop immediately to avoid costlier repairs down the road.
