P2246: O2 Sensor Reference Voltage Circuit High (Bank 1 Sensor 1)

P2246 means the reference voltage line of the bank 1 front wide-band sensor reads too high, typically from a short to battery or heater voltage or a short inside the sensor. No manufacturer publishes a threshold for P2246. GM's 2018 Duramax table 18OBDG04 names it, together with P2245, P2252 and P2253, as a fault that makes the front sensor signal unusable, but gives no setting criteria. Ford logs any wide-band lead that is shorted to supply voltage as P0132 and keeps P2243 for the open line, so Ford vehicles do not use this code. Bosch limits the Nernst cell to a 250 microamp load, which is why an external voltage on this wire can damage the sensor or the interface. CARB requires circuit faults of fuel-control sensors to be detected. P2245 is the low fault, P2250 bank 2.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank. Sensor 1 is the oxygen sensor before the catalytic converter.

Symptoms

• Check engine light
• Higher fuel consumption
• Repeat failure of a new sensor if the wiring short remains

Most likely causes

• Reference voltage wire shorted to heater supply or battery voltage
• Internal short between heater and Nernst cell in the sensor
• Fault in the sensor interface of the ECM

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the wiring and connector of the sensor indicated
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Look for exhaust leaks
4. Check the signal in live data with the engine warm
5. Check the fuse and the heater resistance if the code mentions it
6. Replace the sensor if it has power and does not respond

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P2246 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 2: Fuel injection
• 46: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2246?

Yes, you can normally drive in moderation, but get it repaired soon: you will use more fuel and the catalytic converter can be damaged over time.

What causes code P2246?

The most common causes are: reference voltage wire shorted to heater supply or battery voltage; internal short between heater and Nernst cell in the sensor; fault in the sensor interface of the ECM.

Related codes

• P2243O2 Sensor Reference Voltage Circuit/Open (Bank 1 Sensor 1)
• P2245O2 Sensor Reference Voltage Circuit Low (Bank 1 Sensor 1)
• P2250O2 Sensor Reference Voltage Circuit High (Bank 2 Sensor 1)
• P2239O2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 1)
• P0132O2 Sensor Circuit High Voltage Bank 1 Sensor 1

Sources

• gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
• newtonnet.co.uk: fordobd2012
• bosch-motorsport.com: Data Sheet 69034379 Lambda Sensor LSU 4.9
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.