P2AC6Intake Air O2 Sensor Reference Voltage Circuit High Bank 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2AC6 indicates an excessive reference voltage on the intake oxygen sensor serving bank 2, as happens when the reference wire touches a supply or battery feed, when the sensor ground is open or when moisture bridges the connector pins. Like the other bank 2 codes of this group, it is not documented by any manufacturer; the basis is CARB's general rule that input components must be checked for out-of-range values in both directions. Ford's patents on intake oxygen sensing describe the sensor element and the reference-voltage operation that this check protects. Before replacing the sensor, unplug it and measure the reference lead against ground and against battery voltage with the ignition on. P2AC5 is the low side, P2AC2 the bank 1 counterpart.
- What you may notice
- Check engine light on
- EGR on bank 2 reduced, NOx may rise
- Likely causes
- LikelyReference wire of the bank 2 sensor shorted to a supply or battery feed
- PossibleOpen sensor ground
- PossibleMoisture bridging pins in the connector
- 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.