P2254 OBD-II Trouble Code: O2 Sensor Negative Current Control Circuit/Open Bank 2 Sensor 1

P2254 code definition

O2 sensor negative current control circuit/open bank 2 sensor 1

What the P2254 code means

This trouble code indicates that the powertrain control module has detected a reference voltage from the O2 sensor that is upstream on the second bank of the exhaust that is not within the range of acceptance set by the vehicle’s manufacturer.

What are the causes of the P2254 code?

Some of the potential causes of this trouble code may include:

• The upstream oxygen sensor on the second bank of exhaust could be faulty
• The wiring or connectors that are associated with the oxygen sensor may be faulty
• The fuel pressure could be out of specification and may contribute to this issue
• The engine may have a vacuum leak somewhere that could also be a contributing factor
• The powertrain control module could be malfunctioning

What are the symptoms of the P2254 code?

Some of the symptoms of this trouble code that the driver may experience would include:

• The engine may run rich or lean depending on the direction of variation in the reference voltage (up or down).

• The fuel economy of the vehicle may be decreased.

• The Check Engine Light will likely be illuminated.

How does a mechanic diagnose the P2254 code?

A mechanic may diagnose this trouble code by first getting under the vehicle and inspecting the oxygen sensors for damage. This would also include checking the wiring and connectors that are associated with the oxygen sensor for damage as well. If no damage to the sensor or its circuitry are found, the mechanic would then test the sensor with a digital multimeter using the manufacturer’s recommended procedure. If the oxygen sensor tests good, the mechanic would then do a fuel pressure test and a vacuum test to determine whether or not these numbers are within specification. If these numbers are within specification, the powertrain control module would be tested with a high tech scan tool for proper function. If any issues arise during the diagnosis of this issue, they should be resolved before any further diagnosis takes place.

Common mistakes when diagnosing the P2254 code

A common mistake that could be made when diagnosing this trouble code would be to replace the oxygen sensor without doing any proper testing. Although the oxygen sensor failure is one of the most common causes of this trouble code, it is not the only cause. Therefore, the entire diagnostic procedure should be carried out in order to prevent a misdiagnosis as well as wasted time and money.

How serious is the P2254 code?

This trouble code would rank somewhere in the middle of the seriousness scale. Although no major driveability issues will occur, this trouble code can decrease the gas mileage of any vehicle that has it stored. With this being considered it would be wise to have the issue diagnosed and repaired at the earliest possible opportunity.

What repairs can fix the P2254 code?

Repairs that can potentially resolve the issues that are caused by this trouble code may include:

• Replacing the oxygen sensor that is upstream on the second bank of exhaust

• Repairing or replacing the wiring or connectors that are associated with the oxygen sensor

• Resolving a fuel pressure issue

• Repairing a vacuum leak

• Replacing the powertrain control module

Additional comments regarding the P2254 code

It is possible that other codes related to the upstream oxygen sensor on bank 2 may be stored in addition to this trouble code. If this is the case, it is more likely that the oxygen sensor has failed. All relevant diagnostic procedures should still be carried out in the event that other codes exist.

Need help with a P2254 code?

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