Illustration of OBD codes in a car

Error Code P0030

Moderate Issue
DTC Code P0030 indicates an issue with the HO2S Heater Control Circuit for Bank 1 Sensor 1. This code is triggered when the Engine Control Module (ECM) detects an open circuit in the heater output low side driver circuit of the heated oxygen sensor when the heater is commanded OFF for more than 5 seconds.

What symptoms indicate Error Code P0030?

  • Engine Light ON: The illumination of the engine light or service engine soon warning light is a common symptom of DTC P0030. This indicates a potential issue with the HO2S heater control circuit in Bank 1 Sensor 1.
  • Increased Emissions: A malfunctioning HO2S heater can lead to increased emissions due to improper oxygen sensor operation, affecting the air-fuel mixture.
  • Poor Fuel Economy: The vehicle may experience reduced fuel efficiency as the engine control module (ECM) struggles to maintain the optimal air-fuel ratio.
  • Rough Idle: The engine may idle roughly or experience performance issues due to incorrect oxygen sensor readings.

What causes OBD code Error Code P0030?

  • The heated oxygen sensor may be malfunctioning, leading to incorrect readings and triggering the error code.
  • An open or shorted harness in the sensor's wiring can disrupt the electrical flow, causing the circuit to fail.
  • Poor electrical connections in the sensor's circuit can result in intermittent or no signal transmission.
  • A blown fuse in the sensor's circuit can prevent the heater from functioning, leading to the error code.
  • A faulty Engine Control Module (ECM) can misinterpret sensor data, causing incorrect error codes to be generated.

How to fix OBD code Error Code P0030?

  • Verify DTC Code: Confirm the presence of DTC P0030 using an OBD-II scanner. Clear the code and perform a test drive to see if it returns.
  • Inspect HO2S Heater Circuit: Check the heated oxygen sensor (HO2S) heater circuit for any visible damage or disconnection. Pay special attention to the wiring and connectors.
  • Check HO2S Heater Fuse: Inspect the fuse related to the HO2S heater circuit. Replace the fuse if it is blown and check for any signs of water intrusion in the connector.
  • Test Sensor Resistance: Measure the resistance of the HO2S heater element using a multimeter. Compare the reading with the manufacturer's specifications to ensure it is within range.
  • Inspect Control Module: Verify that the control module is sending the correct voltage to the HO2S heater circuit. Check for any faults in the control module's output.
  • Replace HO2S if Necessary: If all previous checks are satisfactory, replace the heated oxygen sensor. Ensure the new sensor is properly installed and connected.

Similar OBD Codes

P0036

HO2S Heater Control Circuit Issue Bank 1 Sensor 2

P0037

HO2S Heater Control Circuit Low Bank 1 Sensor 2

P0135

O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1

P0141

O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 2

P0443

Evaporative Emission Control System Purge Valve Circuit Malfunction

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