Possible causes

– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 harness is open shorted to ground
– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit poor electrical connection
– Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1
– Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit fuse
– Faulty Engine Control Module (ECM)

When is the code detected?

The P0052 is set when the ECM detects an excessively high voltage through the heated oxygen sensor heater circuit

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0052 BUICK Description

The Heated Oxygen (HO2S) bank 2 sensor 1 is threaded into the exhaust manifold. The sensor is equipped with a heater element to decrease the amount of time required to enter closed loop fuel control. The Engine Control Module (ECM) controls the heater by pulsing circuit 551 to ground. When the heater is commanded Off (circuit not grounded), the voltage level at the ECM should be high (ignition voltage). When the heater is commanded On (circuit grounded), the voltage level at the ECM should be low. The ECM heater feedback circuit uses a pull-up voltage (1.6-3.6 volts), which allows the ECM to individually differentiate between an open, short to ground or short to voltage.