O2 Sensor Reference Voltage Circuit High Bank 1 Sensor 1
P2246 indicates the oxygen sensor reference voltage circuit on Bank 1, Sensor 1 is reading higher than expected. This prevents the PCM from properly monitoring exhaust oxygen levels, which disrupts fuel mixture calibration and emissions control.
What You Might Notice
- Check engine light illumination
- Reduced fuel economy
- Diminished engine performance or hesitation
- Stored lean or rich condition codes
- Rough idle or stumbling during acceleration
Most Common Causes
- 1
Faulty O2 Sensor
The oxygen sensor itself may be defective or degraded, causing abnormal voltage output to the PCM. This is the most common cause of reference voltage circuit codes.
- 2
Blown O2 Sensor Fuse
A blown fuse in the O2 sensor circuit prevents proper voltage regulation and signal transmission, causing the PCM to detect an abnormally high voltage condition.
- 3
Wiring or Connector Issues
Corroded, loose, or damaged wiring and connectors in the O2 sensor circuit can disrupt proper voltage signals and create high voltage readings.
- 4
PCM or ECM Malfunction
A faulty engine control module may incorrectly interpret sensor signals or fail to regulate reference voltage properly, though this is less common than sensor issues.
How to Diagnose It
- 1
Check Faulty O2 Sensor — The oxygen sensor itself may be defective or degraded, causing abnormal voltage output to the PCM. This is the most common cause of reference voltage circuit codes.
- 2
Check Blown O2 Sensor Fuse — A blown fuse in the O2 sensor circuit prevents proper voltage regulation and signal transmission, causing the PCM to detect an abnormally high voltage condition.
- 3
Check Wiring or Connector Issues — Corroded, loose, or damaged wiring and connectors in the O2 sensor circuit can disrupt proper voltage signals and create high voltage readings.
- 4
Check PCM or ECM Malfunction — A faulty engine control module may incorrectly interpret sensor signals or fail to regulate reference voltage properly, though this is less common than sensor issues.
How to Fix It
- 1
Replace Bank 1 Sensor 1 O2 Sensor
Remove the faulty oxygen sensor from the exhaust manifold and install a new replacement. Ensure proper torque specifications and reconnect the electrical connector securely.
- 2
Check and Replace O2 Sensor Fuse
Locate the fuse box, identify the O2 sensor circuit fuse, and replace it with the correct amperage rating. Verify no other electrical issues caused the blown fuse.
- 3
Inspect and Repair Wiring and Connectors
Examine the O2 sensor wiring harness and connector for corrosion, damage, or loose connections. Clean corroded connectors with contact cleaner and reseat connections firmly.
- 4
Reprogram or Replace PCM
If sensor and wiring checks pass, have the PCM scanned and reprogrammed by a professional. If reprogramming fails, the PCM may require replacement.
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