Skip to content
Language: EN
Download

P2243: Oxygen sensor reference voltage circuit open (bank 1, sensor 1)

Electrical fault on the reference wire of the bank 1 wideband oxygen sensor. Usually the connector, a broken wire or the sensor itself.

Code P2243 at a glance
CodeP2243
SystemEngine and transmission
GroupP22xx, NOx sensors, oxygen sensors and emissions
TypeGeneric: it means the same on every make
Can you keep driving?With care

What P2243 means

The wideband oxygen sensor ahead of the catalytic converter works by comparing against a reference voltage supplied by the ECU. This code means that reference circuit is open (broken) or out of range. Without it, the sensor cannot measure and the ECU is adjusting the mixture blind.

Most common causes

  • Loose, dirty or corroded sensor connector
  • Reference wire broken or burnt by the exhaust
  • Faulty wideband oxygen sensor
  • Chafed wiring inside the loom
  • Fault in the ECU circuit (uncommon)

Symptoms

  • Engine warning light on
  • Higher fuel consumption
  • Slightly rough idle
  • Possible loss of response

Can you drive with P2243?

With care You can drive, but the mixture is not controlled properly: consumption goes up and the catalyst can be damaged over time. Get it fixed soon.

How to check it

Look for damage to the sensor lead (melted, chafed or stretched) and make sure the connector is fully home and dry. If P2237 or other codes for the same sensor appear too, it is almost always the wiring or the sensor.

How to read and clear P2243 with Final OBD

Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2243 with this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

P2243 is a generic code, so it means the same on any make, for example on Audi, Fiat, Kia, Mazda, Opel / Vauxhall, Toyota. See what Final OBD does on your car in makes and models.

What does code P2243 mean?

The wideband oxygen sensor ahead of the catalytic converter works by comparing against a reference voltage supplied by the ECU. This code means that reference circuit is open (broken) or out of range. Without it, the sensor cannot measure and the ECU is adjusting the mixture blind.

Can you drive with P2243?

You can drive, but the mixture is not controlled properly: consumption goes up and the catalyst can be damaged over time. Get it fixed soon.

How do you clear P2243?

With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2243 comes back.