P2AF0Intake Air O2 Sensor Negative Current Control Circuit Low Bank 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2AF0 is stored when the negative current control circuit of the bank 2 intake oxygen sensor falls below its window. Because the return is meant to sit at a bias of roughly 2.5 V, which Saab's 2010 9-5 lists as the test value on terminal 2 of its exhaust probe, any path to chassis ground pulls it down: insulation worn through at a clip, a crushed connector or an internal short in the sensor. Ford assigns a grounded VM lead on bank 2 exhaust probes to P0151. No manufacturer publishes P2AF0, so the description rests on CARB's range checks and the Bosch pinout. When bank 1 shows P2AE7 as well, suspect a shared harness section first. With the bias gone, the oxygen value of bank 2 is unusable and EGR is cut back. P2AEF is open, P2AF1 high, P2AED the low fault on the pump lead.
- What you may notice
- Check engine light on
- EGR on bank 2 cut back, possibly higher NOx
- Likely causes
- LikelyReturn lead worn through at a clip or bracket
- PossibleCrushed or damaged sensor connector
- RareInternal short of the sensor to ground
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €0 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.