AutoCodes – Toyota – P0156 2009 Toyota Camry

P0156 2009 Toyota Camry Code - Oxygen Sensor Bank 2 Sensor 2 Circuit Malfunction

Quick Answer

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC is used. Common causes include Faulty Rear Heated Oxygen Sensor Bank 2, Rear Heated Oxygen Sensor Bank 2 harness is open or shorted, Rear Heated Oxygen Sensor Bank 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: P0156 2009 Toyota Camry indicates Oxygen Sensor Bank 2 Sensor 2 Circuit Malfunction.
Common causes: Common causes include Faulty Rear Heated Oxygen Sensor Bank 2, Rear Heated Oxygen Sensor Bank 2 harness is open or shorted, Rear Heated Oxygen Sensor Bank 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 6,464

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 Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0156 2009 Toyota Camry Description

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric air-fuel level. For the purpose of helping the ECM to deliver accurate air-fuel ratio control, a Heated Oxygen (HO2) sensor is used.
The HO2 sensor is located behind the TWC, and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low). When the air-fuel ratio becomes lean, the oxygen concentration in the exhaust gas is rich. The HO2 sensor informs the ECM that the post-TWC air-fuel ratio is lean (low voltage, i.e. less than 0.45 V). Conversely, when the air-fuel ratio is richer than the stoichiometric air-fuel level, the oxygen concentration in the exhaust gas becomes lean. The HO2 sensor informs the ECM that the post-TWC air-fuel ratio is rich (high voltage, i.e. more than 0.45 V). The HO2 sensor has the property of changing its output voltage drastically when the air-fuel ratio is close to the stoichiometric level.
The ECM uses the supplementary information from the HO2 sensor to determine whether the air-fuel ratio after the TWC is rich or lean, and adjusts the fuel injection time accordingly. Thus, if the HO2 sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air-fuel ratio control.

OBDII Code P0156 2009 Toyota Camry - Oxygen Sensor Bank 2 Sensor 2 Circuit Malfunction - AutoCodes.com — P0156 2009 Toyota Camry Code - Oxygen Sensor Bank 2 Sensor 2 Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P0156 2009 Toyota Camry?

Faulty Rear Heated Oxygen Sensor Bank 2
Rear Heated Oxygen Sensor Bank 2 harness is open or shorted
Rear Heated Oxygen Sensor Bank 2 circuit poor electrical connection
EFI Relay
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

How to Fix the DTC P0156 2009 Toyota Camry?

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

Replacing the Rear Heated Oxygen Sensor Bank 2 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0156 2009 Toyota Camry 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.

Need more information about the P0156 2009 Toyota Camry code?

Need more information on how to fix the P0156 2009 Toyota Camry code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P0156 2009 Toyota Camry Code

1. What does OBDII code P0156 indicate for a 2009 Toyota Camry?

The code P0156 for a 2009 Toyota Camry specifically points to a malfunction in the Oxygen Sensor Bank 2 Sensor 2 circuit.

2. What are the common symptoms of a P0156 error in a 2009 Toyota Camry?

Common symptoms of a P0156 error in a 2009 Toyota Camry may include decreased fuel efficiency, rough idling, and the illumination of the check engine light.

3. What are the possible causes of a P0156 error in a 2009 Toyota Camry?

Possible causes of a P0156 error in a 2009 Toyota Camry include a faulty oxygen sensor, damaged wiring or connectors in the sensor circuit, or an exhaust system leak.

4. How can I diagnose the P0156 error in a 2009 Toyota Camry?

Diagnosing a P0156 error in a 2009 Toyota Camry typically involves using an OBDII scanner to retrieve the fault code, inspecting the oxygen sensor and its wiring, and checking for any exhaust leaks.

5. Can I continue driving my 2009 Toyota Camry with a P0156 error code?

While it may be possible to drive your 2009 Toyota Camry with a P0156 error in the short term, it is recommended to address the issue promptly to prevent potential damage to the vehicle's catalytic converter and ensure optimal performance.

6. How do I repair a P0156 error in a 2009 Toyota Camry?

Repairing a P0156 error in a 2009 Toyota Camry typically involves replacing the faulty oxygen sensor, repairing any damaged wiring or connectors, and clearing the error code with an OBDII scanner.

7. Are there any maintenance tips to prevent a P0156 error in a 2009 Toyota Camry?

To help prevent a P0156 error in a 2009 Toyota Camry, it is advisable to follow the manufacturer's recommended maintenance schedule, including regular inspections of the oxygen sensors and the exhaust system.

8. Can a DIY enthusiast fix a P0156 error in a 2009 Toyota Camry?

Depending on their skill level, a DIY enthusiast may be able to replace the oxygen sensor or repair wiring issues causing a P0156 error in a 2009 Toyota Camry. However, professional assistance may be needed for more complex diagnostics or repairs.

9. How much does it cost to repair a P0156 error in a 2009 Toyota Camry?

The cost to repair a P0156 error in a 2009 Toyota Camry can vary depending on the root cause of the issue, the labor rates in your area, and whether you choose to replace the oxygen sensor yourself or have a mechanic do the work.

10. Will resetting the check engine light clear a P0156 error code in a 2009 Toyota Camry?

Resetting the check engine light may temporarily clear a P0156 error code in a 2009 Toyota Camry, but the underlying issue causing the code will need to be addressed to prevent the error from reoccurring.