OBD-II Trouble Code Description for P0038 Toyota

HO2S Heater Control Circuit High

What does this mean?

OBD2 Code P0038 Toyota definition:
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.

Symptoms

Possible sumptoms of OBD code P0038 Toyota
– Engine Light ON (or Service Engine Soon Warning Light)

Causes

Possible causes of OBD code P0038 Toyota
– Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit open shorted to ground – Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit poor electrical connection – Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit – Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit fuse – Faulty Engine Control Module (ECM) The Error code is generally activated on detection of the following conditions: The P0038 Toyota is set when the ECM detects an excessively high voltage through the heated oxygen sensor heater circuit

Possible Solutions

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