Engine-CodesInfiniti – P0138 2006 Infiniti G35

P0138 2006 Infiniti G35 Code - HO2S12 Circuit High Voltage

Quick Answer

The P0138 code for a 2006 Infiniti G35 indicates a problem with the HO2S12 sensor circuit, specifically a high voltage condition. Common causes include Faulty HO2S12 sensor, Damaged wiring or connectors in the sensor circuit, Issues with the ECM. 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
P0138 2006 Infiniti G35 indicates HO2S12 Circuit High Voltage.
Common causes
Common causes include Faulty HO2S12 sensor, Damaged wiring or connectors in the sensor circuit, Issues with the ECM.
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.
Table of contents Created and updated by William Orellana on Sep 12, 2024
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Code P0138 2006 Infiniti G35 Description

The P0138 code for a 2006 Infiniti G35 indicates a problem with the HO2S12 sensor circuit, specifically a high voltage condition. The HO2S12 sensor is one of the oxygen sensors in the exhaust system that monitors the oxygen levels in the exhaust gases. This information is crucial for the engine control module (ECM) to adjust the air-fuel mixture for optimal combustion. When the voltage from the HO2S12 sensor is higher than expected, it can lead to issues with fuel efficiency, emissions, and overall engine performance.

OBDII Code P0138 2006 Infiniti G35 - HO2S12 Circuit High Voltage
P0138 2006 Infiniti G35 Code - HO2S12 Circuit High Voltage

Common Causes of P0138 2006 Infiniti G35

  1. Faulty HO2S12 sensor
  2. Damaged wiring or connectors in the sensor circuit
  3. Issues with the ECM
  4. Exhaust leaks near the sensor
  5. Contaminated sensor from oil or coolant leaks

Symptoms of P0138 2006 Infiniti G35

  1. Decreased fuel efficiency
  2. Increased emissions
  3. Engine misfires
  4. Rough idling
  5. Stalling

How to Fix P0138 2006 Infiniti G35

  1. Diagnose the specific cause of the high voltage condition by using a scan tool to monitor the HO2S12 sensor readings.
  2. Inspect the wiring and connectors in the sensor circuit for any damage or corrosion. Repair or replace as needed.
  3. Test the HO2S12 sensor for proper function and replace if found to be faulty.
  4. Clear the code with a scan tool and drive the vehicle to ensure the issue has been resolved.
  5. If the code returns, further diagnostics may be necessary to identify any underlying issues with the ECM or other components.

Cost to Fix P0138 2006 Infiniti G35

The typical repair costs for addressing a P0138 code on a 2006 Infiniti G35 can range from $100 to $300, depending on the specific cause of the issue and the cost of parts and labor. It's important to keep in mind that diagnosis time and labor rates at auto repair shops can vary, so it's advisable to check with local shops for a more accurate estimate. Be prepared for additional costs if further diagnostics or repairs are needed.

Tech Notes for P0138 2006 Infiniti G35

Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.

When is the Code Detected?

The P0138 code is set when the Engine Control Module (ECM) detects that the rear O2 sensor signal voltage remains excessively high for an extended period of time.

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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 P0138 2006 Infiniti G35 Code

1. What are the common symptoms of OBDII code P0138 on a 2006 Infiniti G35?

- The common symptoms include poor fuel economy, rough idling, engine misfires, and potentially an illuminated Check Engine Light.

2. What does the OBDII code P0138 "HO2S12 Circuit High Voltage" mean on a 2006 Infiniti G35?

- It indicates that the downstream oxygen sensor (HO2S12) in bank 1 sensor 2 is detecting a high voltage condition consistently.

3. What are the possible causes of OBDII code P0138 on a 2006 Infiniti G35?

- The causes may include a faulty oxygen sensor, damaged wiring or connectors in the sensor circuit, exhaust leaks, or issues with the engine's fuel system.

4. How can I diagnose the OBDII code P0138 on my 2006 Infiniti G35?

- You can diagnose the code by performing a visual inspection of the oxygen sensor and its wiring, checking for exhaust leaks, using a scan tool to monitor sensor readings, and testing the sensor's voltage output.

5. Can I continue driving my 2006 Infiniti G35 with OBDII code P0138 present?

- It is not recommended to drive for an extended period with this code active, as it can lead to decreased fuel efficiency and potential damage to the catalytic converter.

6. How can I repair OBDII code P0138 on a 2006 Infiniti G35?

- Repair options may include replacing the downstream oxygen sensor, repairing damaged wiring or connectors, fixing any exhaust leaks, or addressing fuel system issues.

7. Are there any DIY tips for fixing OBDII code P0138 on a 2006 Infiniti G35?

- While some may attempt to replace the oxygen sensor themselves, it is recommended to consult a professional mechanic for proper diagnosis and repair of this code.

8. Will resetting the OBDII code P0138 on a 2006 Infiniti G35 make it go away permanently?

- Resetting the code may temporarily turn off the Check Engine Light, but if the underlying issue causing P0138 is not addressed, the code is likely to return.

9. How much does it typically cost to fix OBDII code P0138 on a 2006 Infiniti G35 at a repair shop?

- The cost of fixing this code can vary depending on the exact cause and parts needed, but it may range from $100 to $300 for parts and labor.

10. Can a bad oxygen sensor cause other codes besides P0138 on a 2006 Infiniti G35?

- Yes, a faulty oxygen sensor can potentially trigger other related codes such as P0139 (HO2S12 Circuit Slow Response) or codes related to fuel trim and air-fuel mixture issues.

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