O2 Sensor Reference Voltage Circuit (Bank 1 Sensor 1)
The P2246 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Reference Voltage Circuit (Bank 1 Sensor 1). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $400 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Engine runs poorly
- Rich or lean condition
- Failed emissions test
- Rough idle
Probable Causes (Ranked by Likelihood)
- Failed O2 sensor heater or internal reference Very High
- Wiring fault in O2 sensor reference circuit High
- ECM O2 reference output circuit fault Moderate
- Corroded O2 sensor connector affecting reference Low
Frequently Asked Questions
What is the O2 sensor reference voltage?
The ECM provides a reference voltage (typically 2.5V or 3.3V) to the wideband O2 sensor to establish a baseline for measuring oxygen content in the exhaust.
Can a bad ECM cause this code?
It is possible but rare. The vast majority of these codes are caused by a failed O2 sensor or wiring issue. Test the sensor and wiring thoroughly before considering ECM replacement.
Do I need a special tool to test this?
A multimeter can measure reference voltage and resistance. A scan tool with live data capability is also very helpful for monitoring O2 sensor operation in real time.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Measure O2 sensor reference voltage at the sensor connector
-
Check ECM reference output at the ECM connector
-
Inspect wiring between ECM and O2 sensor for damage
-
Replace O2 sensor if reference circuit within sensor is faulty
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
Commonly Affected Vehicles
- 2010-2020 Toyota Camry 2.5L
- 2012-2019 Honda Civic 2.0L
- 2008-2018 Ford F-150 5.0L
- 2011-2020 Chevrolet Silverado 5.3L
Related Codes
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