AutoCodes – Saturn – P0156 Saturn

P0156 Saturn Code - Heated Oxygen Sensor Circuit Malfunction 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 Bank 2 Sensor 2, Heated Oxygen Sensor Bank 2 Sensor 2 harness is open or shorted, Heated Oxygen Sensor Bank 2 Sensor 2 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0156 Saturn indicates Heated Oxygen Sensor Circuit Malfunction Bank 2 Sensor 2.
Common causes: Common causes include Faulty Heated Oxygen Sensor Bank 2 Sensor 2, Heated Oxygen Sensor Bank 2 Sensor 2 harness is open or shorted, Heated Oxygen Sensor Bank 2 Sensor 2 circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 586

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Dec 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0156 Saturn 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. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The Powertrain Control Module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started the PCM operates in an open loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and a closed loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream; low HO2S voltage indicates a lean exhaust stream.
The HO2S bank 1 sensor 2 and HO2S bank 2 sensor 2 are used for catalyst monitoring. This diagnostic runs once per ignition cycle. This diagnostic consists of two tests, a passive test, and an intrusive test. During the passive test, if the HO2S bank 1 sensor 2 or HO2S bank 2 sensor 2 voltage transitions below 350 mV and above 709 mV, the DTC will pass for this ignition cycle. If the DTC does not pass during the passive test, the intrusive test will begin. During the intrusive test, the control module will force the air-to-fuel ratio rich and/or lean. The control module then waits for a predicted response from the HO2S. If the HO2S voltage transitions below 350 mV and/or above 709 mV, the DTC will pass for this ignition cycle. If the control module does not receive the expected response from the HO2S, DTC P0136 will set for HO2S bank 1 sensor 2 or DTC P0156 will set for HO2S bank 2 sensor 2.

OBDII Code P0156 Saturn - Heated Oxygen Sensor Circuit Malfunction Bank 2 Sensor 2 - AutoCodes.com — P0156 Saturn Code - Heated Oxygen Sensor Circuit Malfunction Bank 2 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0156 Saturn?

Faulty Heated Oxygen Sensor Bank 2 Sensor 2
Heated Oxygen Sensor Bank 2 Sensor 2 harness is open or shorted
Heated Oxygen Sensor Bank 2 Sensor 2 circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC P0156 Saturn?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0156 Saturn 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 P0156 Saturn Code

1. What are the common symptoms of OBDII code P0156 in a Saturn vehicle?

- Common symptoms include decreased fuel efficiency, rough idling, and the illumination of the Check Engine light.

2. What does the OBDII code P0156 indicate in a Saturn vehicle?

- The code P0156 indicates a malfunction in the heated oxygen sensor circuit for Bank 2 Sensor 2 in the Saturn's exhaust system.

3. What are the possible causes of the P0156 code in a Saturn?

- Common causes of the P0156 code include a faulty oxygen sensor, damaged wiring or connectors, exhaust leaks, or issues with the engine computer.

4. How can I diagnose the cause of the P0156 code in my Saturn?

- Diagnosing the P0156 code typically involves using an OBDII scanner to retrieve the specific fault code, inspecting the oxygen sensor and its wiring, and checking for any exhaust leaks.

5. Can I drive my Saturn with the P0156 code present?

- It is generally safe to drive your Saturn with the P0156 code, but it is recommended to address the issue promptly to prevent further damage to the vehicle's emissions system.

6. How can I repair the P0156 code in my Saturn?

- Repairing the P0156 code usually 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 DIY tips for fixing the P0156 code in a Saturn?

- DIY tips for fixing the P0156 code include checking and securing the oxygen sensor wiring, inspecting the sensor for physical damage, and ensuring the exhaust system is free of leaks.

8. How much does it cost to repair the P0156 code in a Saturn at a mechanic?

- The cost of repairing the P0156 code in a Saturn can vary depending on the specific issue, but it typically ranges from $150 to $400, including parts and labor.

9. How long does it take to repair the P0156 code in a Saturn?

- Repairing the P0156 code in a Saturn can take anywhere from 1 to 2 hours, depending on the complexity of the issue and the availability of parts.

10. Can the P0156 code cause any long-term damage to my Saturn if left unaddressed?

- Ignoring the P0156 code for an extended period can lead to decreased fuel efficiency, increased emissions, and potential damage to the catalytic converter in your Saturn.