P2244
O2 Sensor Reference Voltage Performance (Bank 1 Sensor 1)
- Severity
- Medium
- Driving
- Drivable — book it in
The reference voltage for the upstream oxygen sensor on bank 1 is present but not performing as it should - drifting, unstable, or not holding its value under load. The sensor's readings are derived from that reference, so an unsteady reference makes a healthy sensor report inaccurate mixture.
Possible causes
- CommonHigh resistance in the reference wiring or a corroded connector
- CommonFailing oxygen sensor
- CommonPoor earth on the sensor circuit
- PossibleUnstable system voltage from a charging fault
- PossibleFailed control module reference supply
What you might notice
- Check engine light on
- Fuel trim values drifting
- Worse fuel economy
- Failed emissions test
- Hesitation in some conditions
What to check, in order
- Check system voltage first. An unstable supply to the whole vehicle shows up on reference circuits before it shows up anywhere obvious.
- Perform a voltage drop test on the reference and earth circuits at the sensor.
- Inspect the connector for corrosion and heat damage.
- Watch the fuel trim values alongside this code - they show what the module is doing with the sensor's readings.
- Check for other reference voltage codes stored, which would point at a shared supply rather than this sensor.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Fuel and air metering - injector circuits
P2200P2201P2202P2203P2204P2205P2206P2207P2208P2209P2210P2211P2212P2213P2214P2215P2216P2217P2218P2219P2220P2221P2222P2223P2224P2225P2226P2227P2228P2229P2230P2231P2232P2233P2234P2235P2236P2237P2238P2239P2240P2241P2242P2243P2244P2245P2246P2247P2248P2249P2250P2251P2252P2253P2254P2255P2256P2257P2258P2259P2260P2261P2262P2263P2264P2265P2266P2267P2268P2269P2270P2271P2272P2273P2274P2275P2276P2277P2278P2279P2280P2281P2282P2283P2284P2285P2286P2287P2288P2289P2290P2291P2292P2293P2294P2295P2296P2297P2298P2299