P2253 Buick Oxygen (O2) Sensor Negative Current Control Circuit High (Bank 1 – Sensor 1)

P2254 Buick Oxygen (O2) Sensor Negative Current Control Circuit / Open (Bank 2 – Sensor 1)

Possible causes
– Rear Air/Fuel Ratio Sensor Bank 2 Sensor 1 harness is open or shorted
– Rear Air/Fuel Ratio Sensor Bank 2 Sensor 1 circuit poor electrical connection
– Faulty Rear Air/Fuel Ratio Sensor Bank 2 Sensor 1
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P2254 Buick Description

The rear air/fuel ratio (A/F) sensor (bank 2, sensor 1) is installed in the exhaust manifold and detects oxygen content in the exhaust gas. The rear A/F sensor transmits a signal to the powertrain control module (PCM), and it enables overall feedback control. The PCM controls fuel injection duration by comparing the target air/fuel ratio with the rear A/F sensor signal. When the VSB1 terminal voltage is more than a specified value for a predetermined time, the PCM detects a malfunction and stores a DTC.

Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera