Possible causes

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

Tech notes

HO2S Heater Control Circuit High Bank 1 Sensor 2 is the generic definition for the P0038; however your vehicle’s manufacturer may have a different definition and information for the P0038 code.

When is the code detected?

The P0038 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)

P0038 Description

Oxygen Sensors (O2S) or Heated Oxygen Sensors (HO2S) need to reach a minimum operating temperature of 750 degrees F to produce an accurate voltage signal. The faster the heated oxygen sensor reaches that temperature the faster the sensor will start sending an accurate signal to the Engine Control Module (ECM).
In order to achieve the require temperature, a heater element is included inside the heated oxygen sensor. The ECM controls the heated oxygen sensor heater element based on signals from the engine coolant temperature and engine load. The ECM controls the heater element circuit by allowing current flow to ground.
The ECM monitors the voltage signal received through the heater element circuit and determines the state of the circuit by comparing the voltage detected with the factory specifications.

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P0038 Information for specific makes

P0038 AUDI
P0038 BMW
P0038 CHRYSLER
P0038 DODGE
P0038 HYUNDAI
P0038 INFINITI
P0038 JEEP
P0038 KIA
P0038 LEXUS
P0038 MAZDA
P0038 MITSUBISHI
P0038 NISSAN
P0038 SCION
P0038 SUBARU
P0038 SUZUKI
P0038 TOYOTA
P0038 VOLKSWAGEN
P0038 BUICK
P0038 CADILLAC
P0038 CHEVROLET
P0038 GMC
P0038 PONTIAC
P0038 SATURN