O2 Sensor Reference Voltage Circuit Low Bank 1 Sensor 1
The P2245 code indicates that the oxygen sensor (O2S) for Bank 1 Sensor 1 has a reference voltage circuit that is lower than expected. This sensor is located upstream of the catalytic converter and monitors the air-fuel ratio. The reference voltage is typically 5V supplied by the powertrain control module (PCM). A low voltage condition can be caused by a faulty sensor, wiring issues, or a PCM problem, leading to incorrect fuel trim adjustments and potential drivability issues.
01. Most Common Causes
- Faulty oxygen sensor (Bank 1 Sensor 1)
- Open or shorted wiring in the sensor circuit
- Corroded or damaged connector
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or hesitation
- Failed emissions test
03. Step-by-Step Diagnosis
Step 1: Scan the vehicle for codes and record freeze frame data.
Step 2: Visually inspect the O2 sensor wiring and connector for damage or corrosion.
Step 3: Measure reference voltage at the sensor connector (should be ~5V with key on engine off).
Step 4: If voltage is low, check for continuity and shorts in the wiring between sensor and PCM.
Step 5: If wiring is okay, replace the oxygen sensor and clear codes.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short distances, but prolonged driving may cause poor fuel economy and potential damage to the catalytic converter. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
The cost typically ranges from $150 to $300, including parts and labor. The sensor itself costs $50-$150, and labor adds $50-$150 depending on the vehicle.