Faulty upstream oxygen sensor (bank 1 sensor 1) with an internal reference voltage circuit failure; Damaged or corroded wiring or connector at the oxygen sensor or PCM; Open or shorted reference voltage circuit between the sensor and PCM; PCM internal fault affecting the reference voltage supply; Exhaust leak before the sensor allowing outside air to affect the reading; Contaminated sensor from oil or coolant entering the exhaust stream

DTC codes / P22xx · Fuel and air metering (injector circuits) / P2244

P2244O2 Sensor Reference Voltage Performance (Bank 1 Sensor 1)

Q: What does code P2244 mean?

O2 Sensor Reference Voltage Performance (Bank 1 Sensor 1). P2244 indicates that the powertrain control module (PCM) has detected a performance fault in the reference voltage circuit for the upstream oxygen sensor on bank 1, sensor 1. The PCM monitors the sensor's reference voltage and sets this code when the voltage falls outside the expected range or does not respond correctly during key-on or closed-loop operation.

P2244 indicates that the powertrain control module (PCM) has detected a performance fault in the reference voltage circuit for the upstream oxygen sensor on bank 1, sensor 1. The PCM monitors the sensor's reference voltage and sets this code when the voltage falls outside the expected range or does not respond correctly during key-on or closed-loop operation.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or hesitation during acceleration if the sensor feedback is skewed
Decreased fuel economy due to incorrect air-fuel ratio control
Failed emissions test because the oxygen sensor monitor is not ready or the sensor is not switching
Intermittent misfire or surging at steady speeds in some cases

Common causes, most likely first

Faulty upstream oxygen sensor (bank 1 sensor 1) with an internal reference voltage circuit failure
Damaged or corroded wiring or connector at the oxygen sensor or PCM
Open or shorted reference voltage circuit between the sensor and PCM
PCM internal fault affecting the reference voltage supply
Exhaust leak before the sensor allowing outside air to affect the reading
Contaminated sensor from oil or coolant entering the exhaust stream

How to diagnose and fix it

Connect a scan tool and verify the code is current; check freeze-frame data for engine conditions when the fault set
Inspect the oxygen sensor wiring and connector for damage, corrosion, or loose pins; repair as needed
Measure reference voltage at the sensor connector with the key on; compare to manufacturer specification
Check for exhaust leaks upstream of the sensor using a smoke machine or visual inspection
Perform a resistance and continuity test on the sensor's heater circuit and reference circuit
If voltage is incorrect at the sensor but correct at the PCM, repair the wiring harness; if correct at the sensor, replace the sensor
Clear codes and perform a road test to confirm the repair and ensure the monitor runs to completion

Reference voltage faults often misdiagnosed

A P2244 can be set by a poor ground connection at the sensor or engine block, which skews the reference voltage without any sensor failure.
Technicians sometimes replace the oxygen sensor only to find the connector pins are pushed back or corroded, so always perform a voltage drop test under load.
The code may appear intermittently due to vibration or heat affecting a marginal wire, so wiggle-test the harness while monitoring live data.
An exhaust leak before the sensor can cause the sensor to read lean and set a reference voltage code, so inspect the exhaust system before condemning the sensor.
On some vehicles, a weak battery or charging system issue can cause low reference voltage and set this code, so check system voltage first.

Can I keep driving with P2244?

You can usually drive with this code, but avoid aggressive acceleration and long trips until it is diagnosed, as fuel economy and emissions may suffer. If the engine runs rough or misfires, have it checked promptly to prevent damage to the catalytic converter.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.