AutoCodes – Generic – P0056

P0056 Code - HO2S Heater Control Circuit Bank 2 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 2 Sensor 2, Heated Oxygen Sensor Bank 2 Sensor 2 harness is open shorted, Heated Oxygen Sensor Bank 2 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: P0056 indicates HO2S Heater Control Circuit Bank 2 Sensor 2.
Common causes: Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 2, Heated Oxygen Sensor Bank 2 Sensor 2 harness is open shorted, Heated Oxygen Sensor Bank 2 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 59,046

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
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0056 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 an open circuit in the heater output low side driver circuit of the heated oxygen sensor when the heater is commanded OFF for greater than 5 s.

OBDII Code P0056 - HO2S Heater Control Circuit Bank 2 Sensor 2 - AutoCodes.com — P0056 Code - HO2S Heater Control Circuit Bank 2 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0056?

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

How to Fix the DTC P0056?

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 P0056 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

P0056 Audi — HO2S Heater Control Circuit Bank 2 Sensor 2
P0056 BMW — HO2S 22 Heater Control Circuit
P0056 Buick — HO2S Heater Control Circuit Bank 2 Sensor 2
P0056 Cadillac — HO2S Heater Control Circuit Bank 2 Sensor 2
P0056 Chevrolet — HO2S Heater Control Circuit Bank 2 Sensor 2
P0056 Ford — HO2S Heater Control Circuit Bank 2 Sensor 2
P0056 GMC — HO2S Heater Control Circuit Bank 2 Sensor 2
P0056 Hyundai — HO2S 22 Heater Control Circuit Fault
P0056 KIA — HO2S 22 Heater Circuit Malfunction
P0056 Lincoln — HO2S Heater Control Circuit Bank 2 Sensor 2
P0056 Mercedes-Benz — HO2S Heater Control Circuit Bank 2 Sensor 2
P0056 MINI — HO2S 22 Heater Control Circuit
P0056 Subaru — HO2S 22 Heater Control Circuit
P0056 Suzuki — HO2S22 Heater Resistance Out Of Limits
P0056 Volkswagen — HO2S Heater Control Circuit Bank 2 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 P0056 Code

1. What does OBDII code P0056 mean?

- OBDII code P0056 stands for HO2S Heater Control Circuit Bank 2 Sensor 2, indicating an issue with the oxygen sensor heater circuit in the second bank of cylinders after the catalytic converter.

2. What are the common symptoms of OBDII code P0056?

- Common symptoms of P0056 include poor fuel economy, rough idling, stalling, and the illumination of the Check Engine Light on the dashboard.

3. What could cause OBDII code P0056 to trigger?

- The most common causes of P0056 are a faulty oxygen sensor, damaged wiring or connectors in the sensor circuit, a blown fuse, or a problem with the engine control module (ECM).

4. How serious is OBDII code P0056?

- While P0056 may not cause immediate drivability issues, it can lead to decreased fuel efficiency and increased emissions. It is essential to address this code promptly to prevent further damage to the vehicle.

5. Can I drive my vehicle with OBDII code P0056?

- It is generally safe to drive your vehicle with code P0056, but it is recommended to have the issue diagnosed and repaired as soon as possible to avoid potential long-term damage and increased fuel consumption.

6. How do I diagnose OBDII code P0056?

- Diagnosing P0056 involves using a scan tool to read the code, inspecting the wiring and connectors related to the oxygen sensor, checking the sensor's resistance, and testing the heater circuit.

7. How can I fix OBDII code P0056?

- To fix P0056, you may need to replace the oxygen sensor, repair damaged wiring or connectors, replace a blown fuse, or reprogram the ECM. It is best to consult a professional mechanic for an accurate diagnosis and repair.

8. Will resetting the Check Engine Light resolve OBDII code P0056?

- Simply resetting the Check Engine Light will not fix P0056. The underlying issue causing the code needs to be identified and addressed to prevent the light from coming back on.

9. How much does it cost to repair OBDII code P0056?

- The cost of repairing P0056 can vary depending on the cause of the issue, the labor rates in your area, and the type of vehicle you have. Generally, replacing an oxygen sensor can cost between $200 to $500, including parts and labor.

10. Can a DIY enthusiast fix OBDII code P0056?

- While some enthusiasts may have the skills to diagnose and replace an oxygen sensor, diagnosing and repairing P0056 can be complex. It is recommended to seek the help of a professional mechanic to ensure the issue is properly resolved.