OBD-II code family
Oxygen Sensor Positive Current Control Circuit Faults (6 codes)
6 related fault descriptions. Use each full code and the exact vehicle service information to identify its circuit, monitored condition, and required tests.
Codes in this family
This is the complete published member list for this guide. Each code retains its own page; shared diagnostic context does not mean that every member has the same test or repair.
- P2237O2 Sensor Positive Current Control Circuit/Open (Bank 1 Sensor 1)
- P2238O2 Sensor Positive Current Control Circuit Low (Bank 1 Sensor 1)
- P2239O2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 1)
- P2240O2 Sensor Positive Current Control Circuit/Open (Bank 2 Sensor 1)
- P2241O2 Sensor Positive Current Control Circuit Low (Bank 2 Sensor 1)
- P2242O2 Sensor Positive Current Control Circuit High (Bank 2 Sensor 1)
What these codes mean
These six codes preserve two banks and three reported conditions. P2237/P2238/P2239 identify Bank 1 Sensor 1 circuit/open, low and high positive-current control results; P2240/P2241/P2242 identify the corresponding Bank 2 Sensor 1 results. The current-control designation concerns the sensing interface. It does not establish an engine-mixture direction, heater failure or a replacement part.
Identify the installed sensor, receiving interface and circuit diagram before interpreting a reading. Bank numbering does not supply a firewall location, lead length or access estimate. The number of wires does not select a universal wideband pinout. A normal-looking value on another bank is useful only when the applicable procedure supports that comparison; it does not certify the comparison circuit or its shared connections.
Actual monitors illustrate why the labels need this care. The Mitsubishi NS22/2022 P2237 entry evaluates pumping current together with relevant circuit-voltage relationships. Ford's covered 2024–2025 summary distinguishes interface-specific positive-current, reference and negative-current checks. These are examples of specific electrical relationships rather than a rule to assess every terminal as a conventional switching oxygen-signal voltage.
Low and high do not supply a universal open/short truth table. In the 2005 GM L66 engine parameters, P2238/P2241 are pump-cell short checks and P2239/P2242 are pump-cell open checks. Toyota's 2AZ-FE excerpt instead includes a P2239 air-fuel positive-circuit short-to-battery example and conditional circuit checks for P2238. Neither example should be transplanted to an installation it does not cover.
Sensor assembly details also matter. Bosch's LSU 4.9 datasheet distinguishes pump current, virtual ground, Nernst voltage, heater and connector trim functions. Its factory-connector trimming resistor does not make a correct complete used assembly inherently mismatched to its own connector. The Toyota 2AZ-FE diagram separately identifies sensing and heater connections; it is not evidence that every installation has the same terminal count.
Save the full scan, event status, warnings and recent repair history. Keep heater, reference, mixture and companion-bank reports together so the technician can follow the correct diagnostic order. Several codes do not prove one shared failure, and no code on the other bank does not prove that bank is healthy.
Have the prescribed protected checks distinguish the sensor assembly from terminals, wiring and the receiving interface. Do not inject current, bridge terminals, disconnect a powered interface, swap sensors or manipulate a hot harness to force a result. Clearing memory or observing one normal trip does not replace the applicable repair verification.
Ask for a quote after the actual job has been identified, including any required setup and monitor verification. A sensor code cannot predict parts, labour or a fixed fallback. Stop safely and seek assistance for severe running changes, stalling or unreliable acceleration; these labels cannot establish a safe driving distance.
Identify the circuit on your vehicle
Match the full DTC, reporting module, and any failure-type suffix to the service information for your exact year, make, model, engine, and equipment. An identifier alone does not establish installed hardware count, location, connector pinout, or a universal measurement.
Where the manufacturer publishes its own meaning for this code, that is the one to work from — it describes the actual component on your vehicle, which the generic definition cannot. Keep the generic description for what it is good for: it tells you which subject area the standard assigned the code to, which is useful context when the two appear to disagree. If they do disagree, follow the manufacturer.