AutoCodes – Generic – P0038

P0038 Code - HO2S Heater Control Circuit High Bank 1 Sensor 2

Quick Answer

Heated Oxygen Sensors (HO2S) are used for fuel control and post catalyst monitoring. Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2, Heated Oxygen Sensor Bank 1 Sensor 2 harness is open shorted to ground, Heated Oxygen Sensor Bank 1 Sensor 2 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P0038 indicates HO2S Heater Control Circuit High Bank 1 Sensor 2.
Common causes: Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2, Heated Oxygen Sensor Bank 1 Sensor 2 harness is open shorted to ground, Heated Oxygen Sensor Bank 1 Sensor 2 circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 55,158

How popular is this code, among other codes? Medium

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 23, 2024

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0038 Description

Heated Oxygen Sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach an operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensors to reach operating temperature. Voltage is provided to the heater by an ignition voltage circuit through a fuse. With the engine running, the ground is provided to the heater by the HO2S heater low control circuit through a low side driver within the Engine Control Module (ECM). The ECM uses Pulse Width Modulation (PWM) to control the HO2S heater operation to maintain a specific HO2S operating temperature range.
The Diagnostic Trouble Code (DTC) will be set when the ECM detects a short to voltage in the heater output low side driver circuit of the heated oxygen sensor when the heater is commanded ON for greater than 5 s.

OBDII Code P0038 - HO2S Heater Control Circuit High Bank 1 Sensor 2 - AutoCodes.com — P0038 Code - HO2S Heater Control Circuit High Bank 1 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0038?

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

How to Fix the DTC P0038?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The code means that there is a problem with the heater element circuit of the heated oxygen sensor. The control module monitors how long it takes the sensor to warm up and start sending an adequate signal. The code is set when the sensor is taking too long to warm up. Water getting inside the heated oxygen sensor connector can cause the heated oxygen sensor fuse to blow. Before replacing the sensor, check for the condition of the heated oxygen sensor fuse and connectors. If the fuse and connector are OK, replacing the O2 Sensor usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0038 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Makes

P0038 Audi — HO2S Heater Control Circuit High Bank 1 Sensor 2
P0038 BMW — HO2S 12 Heater Control Circuit High
P0038 Buick — HO2S Heater Control Circuit High Voltage Bank 1 Sensor 2
P0038 Cadillac — HO2S Heater Control Circuit High Voltage Bank 1 Sensor 2
P0038 Chevrolet — HO2S Heater Control Circuit High Voltage Bank 1 Sensor 2
P0038 Chrysler — O2 Sensor 1/2 Heater Circuit High
P0038 Dodge — O2 Sensor 1/2 Heater Circuit High
P0038 Ford — HO2S Heater Control Circuit High Bank 1 Sensor 2
P0038 GMC — HO2S Heater Control Circuit High Voltage Bank 1 Sensor 2
P0038 Hyundai — HO2S 12 Heater Circuit High
P0038 Infiniti — HO2S12 Heater Control Circuit High
P0038 Jeep — O2 Sensor 1/2 Heater Circuit High
P0038 KIA — HO2S 12 Hater Circuit High Input
P0038 Lexus — Oxygen Sensor Heater Control Circuit High Bank 1 Sensor 2
P0038 Lincoln — HO2S Heater Control Circuit High Bank 1 Sensor 2
P0038 Mazda — HO2S Heater Control Circuit High 12
P0038 Mercedes-Benz — HO2S Heater Control Circuit High Bank 1 Sensor 2
P0038 MINI — HO2S 12 Heater Control Circuit High
P0038 Mitsubishi — Cylinder 1-4 Heated Oxygen Sensor Rear Heater Control Circuit High
P0038 Nissan — HO2S12 Heater Control Circuit High
P0038 Pontiac — HO2S Heater Control Circuit High Voltage Bank 1 Sensor 2
P0038 Saturn — HO2S Heater Control Circuit High Voltage Bank 1 Sensor 2
P0038 Scion — Oxygen Sensor Heater Control Circuit High Bank 1 Sensor 2
P0038 Subaru — HO2S12 Heater Control Circuit High
P0038 Suzuki — HO2S12 Heater Control Circuit High
P0038 Toyota — Oxygen Sensor Heater Control Circuit High Bank 1 Sensor 2
P0038 Volkswagen — HO2S Heater Control Circuit High Bank 1 Sensor 2

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0038 Code

1. What does the OBDII code P0038 mean?

P0038 indicates a problem with the Heated Oxygen Sensor (HO2S) Heater Control Circuit on Bank 1, Sensor 2, where the voltage is higher than expected.

2. What are the symptoms of a P0038 code?

Common symptoms include an illuminated Check Engine Light, decreased fuel efficiency, and possibly a failed emissions test.

3. What causes the P0038 code to appear?

Potential causes include a faulty oxygen sensor, damaged wiring, a blown fuse, or a malfunctioning Engine Control Module (ECM).

4. Is it safe to drive with a P0038 code?

While it may be safe to drive short-term, ignoring the code can lead to poor fuel efficiency and damage to the catalytic converter over time.

5. How do you fix a P0038 code?

Repairs may involve replacing the oxygen sensor, repairing damaged wiring, checking and replacing fuses, or addressing ECM issues if necessary.

6. How can I diagnose the P0038 code?

Use a multimeter to check the resistance of the oxygen sensorâ€™s heater circuit and inspect wiring for shorts, breaks, or corrosion.

7. What is Bank 1, Sensor 2?

Bank 1 refers to the side of the engine with cylinder 1, and Sensor 2 refers to the downstream oxygen sensor, located after the catalytic converter.

8. Can a P0038 code cause other codes to appear?

Yes, related codes such as P0037 (HO2S Heater Control Circuit Low) or other oxygen sensor codes may also appear if the problem persists.

9. How much does it cost to fix a P0038 code?

Repair costs vary but typically range from $150 to $300, depending on whether the oxygen sensor or wiring needs replacement.

10. Can a bad oxygen sensor heater affect emissions?

Yes, a malfunctioning heater can prevent the sensor from reaching optimal operating temperature, leading to inaccurate readings and increased emissions.