AutoCodes – Acura – P0155 Acura

P0155 Acura Code - A/F Sensor 21 Heater System Malfunction

Quick Answer

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. Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1, Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit fuse, Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 harness is open shorted to ground. 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: P0155 Acura indicates A/F Sensor 21 Heater System Malfunction.
Common causes: Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1, Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 circuit fuse, Heated Oxygen Sensor (H2OS) Bank 2 Sensor 1 harness is open shorted to ground.
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 17,157

How popular is this code, among other codes? Low

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 P0155 Acura 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.

OBDII Code P0155 Acura - A/F Sensor 21 Heater System Malfunction - AutoCodes.com — P0155 Acura Code - A/F Sensor 21 Heater System Malfunction

What does this mean?

What are the Possible Causes of the DTC P0155 Acura?

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

How to Fix the DTC P0155 Acura?

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 Engine Control Module (ECM) monitors how long it takes the sensor to warm up and start sending an adequate signal. The code means the sensor is taking too long to warm up. Replacing the Front Heated Oxygen Sensor (H2OS) Bank 2 usually takes care of the problem.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0155 Acura 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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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 P0155 Acura Code

1. What is the OBDII code P0155 for Acura?

The OBDII code P0155 for Acura refers to a malfunction in the A/F Sensor 21 Heater System.

2. What are the common symptoms of a P0155 code in an Acura?

Common symptoms of a P0155 code in an Acura may include poor fuel economy, rough idling, and an illuminated check engine light.

3. What causes the P0155 code to appear in an Acura?

The P0155 code in an Acura is typically triggered by a faulty A/F sensor, wiring issues, or a blown fuse related to the A/F sensor heater circuit.

4. How can I diagnose a P0155 code in my Acura?

Diagnosing a P0155 code in your Acura involves using an OBDII scanner to retrieve the code, checking the A/F sensor heater circuit for continuity, and inspecting the sensor and its wiring for any visible damage.

5. Can I drive my Acura with a P0155 code?

It is not recommended to drive your Acura with a P0155 code as it can lead to poor engine performance and potential damage if left unresolved.

6. How do I repair a P0155 code in my Acura?

To repair a P0155 code in your Acura, you may need to replace the faulty A/F sensor, repair any damaged wiring, or replace blown fuses related to the A/F sensor heater circuit.

7. Is it safe to reset the P0155 code in my Acura using an OBDII scanner?

Resetting the P0155 code using an OBDII scanner may temporarily turn off the check engine light, but it is important to address the underlying issue causing the code to prevent further problems.

8. Can a DIY enthusiast fix a P0155 code in an Acura?

Depending on your experience and access to tools, some DIY enthusiasts may be able to fix a P0155 code in an Acura by following repair guides and being cautious with electrical components.

9. How much does it cost to repair a P0155 code in an Acura?

The cost to repair a P0155 code in an Acura can vary depending on the cause of the issue, but it may range from $200 to $500 for parts and labor.

10. Will a P0155 code affect my Acura's emissions or performance?

Yes, a P0155 code in an Acura can affect emissions levels and engine performance, leading to increased fuel consumption and potential issues with passing emissions tests.