Engine-Codes.com
Engine-Codes – Nissan – P0138 2006 Nissan Maxima

P0138 2006 Nissan Maxima Code - HO2S12 Circuit High Voltage

Quick Answer

The diagnostic trouble code P0138 in a 2006 Nissan Maxima indicates an issue with the HO2S12 (Heated Oxygen Sensor 1 Bank 1 Sensor 2) circuit registering high voltage. Common causes include Faulty HO2S12 sensor, Wiring issues such as shorts or open circuits, ECM malfunction. 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 Nissan Maxima indicates HO2S12 Circuit High Voltage.
Common causes
Common causes include Faulty HO2S12 sensor, Wiring issues such as shorts or open circuits, ECM malfunction.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 15, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0138 2006 Nissan Maxima Description

The diagnostic trouble code P0138 in a 2006 Nissan Maxima indicates an issue with the HO2S12 (Heated Oxygen Sensor 1 Bank 1 Sensor 2) circuit registering high voltage. The HO2S12 sensor is responsible for monitoring the oxygen levels in the exhaust gases and sending this information to the engine control module (ECM) to adjust the air-fuel mixture for optimal combustion. When the voltage from the sensor is higher than expected, it can lead to various performance issues in the vehicle.

OBDII Code P0138 2006 Nissan Maxima - HO2S12 Circuit High Voltage
P0138 2006 Nissan Maxima Code - HO2S12 Circuit High Voltage

Common Causes of P0138 2006 Nissan Maxima

  1. Faulty HO2S12 sensor
  2. Wiring issues such as shorts or open circuits
  3. ECM malfunction
  4. Exhaust leaks near the sensor
  5. Contaminated sensor due to oil or coolant leaks

Symptoms of P0138 2006 Nissan Maxima

  1. Decreased fuel efficiency
  2. Rough idling
  3. Poor acceleration
  4. Check Engine Light illuminated
  5. Potential fuel smell from exhaust

How to Fix P0138 2006 Nissan Maxima

  1. Begin by conducting a visual inspection of the sensor and its wiring to check for any obvious signs of damage or contamination.
  2. Use a multimeter to test the voltage output of the sensor to determine if it is within the specified range.
  3. If the sensor is faulty, replace it with a new OEM or high-quality aftermarket sensor.
  4. Check and repair any damaged wiring or connectors leading to the sensor.
  5. Clear the diagnostic trouble codes from the ECM and perform a test drive to ensure the issue has been resolved.

Cost to Fix P0138 2006 Nissan Maxima

The cost of repairing a P0138 code in a 2006 Nissan Maxima can vary depending on the specific cause of the issue. Typically, the cost of a new HO2S12 sensor ranges from $50 to $200, with labor costs adding an additional $100 to $200. Overall, the total repair cost could range from $150 to $400. It's important to note that these are rough estimates, and actual costs may vary based on the location, labor rates, and any additional parts or services required. It's recommended to consult with a trusted mechanic or auto repair shop for a more accurate cost estimate.

What does this mean?

Tech Notes for P0138 2006 Nissan Maxima

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.

Need more information about the P0138 2006 Nissan Maxima code?

Need more information on how to fix the P0138 2006 Nissan Maxima code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0138 2006 Nissan Maxima code diagnosed by a professional: Find a repair shop in your area

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 Nissan Maxima Code

1. What does the OBDII code P0138 for a 2006 Nissan Maxima indicate?

- The code P0138 indicates that the HO2S12 oxygen sensor circuit has detected high voltage.

2. What are the common symptoms of a P0138 code in a 2006 Nissan Maxima?

- Common symptoms include poor fuel economy, rough idling, engine misfires, and the illumination of the Check Engine light.

3. What are the potential causes of a P0138 code in a 2006 Nissan Maxima?

- Possible causes 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 cause of a P0138 code in my 2006 Nissan Maxima?

- To diagnose the issue, you can use a scan tool to monitor the oxygen sensor's voltage readings and inspect the sensor wiring and connectors for any visible damage.

5. Can a P0138 code be triggered by a loose gas cap on a 2006 Nissan Maxima?

- While a loose gas cap can trigger a different code related to the evaporative emissions system, it is unlikely to cause a P0138 code specifically.

6. What are some repair tips for fixing a P0138 code in a 2006 Nissan Maxima?

- Repair tips may include replacing the HO2S12 oxygen sensor, repairing or replacing damaged wiring or connectors, and addressing any exhaust leaks in the system.

7. Is it safe to continue driving my 2006 Nissan Maxima with a P0138 code?

- It is generally not recommended to continue driving with a P0138 code, as it can lead to decreased fuel efficiency and potential damage to the engine over time.

8. How much does it typically cost to repair a P0138 code on a 2006 Nissan Maxima?

- The cost of repairing a P0138 code can vary depending on the specific issue, but it may range from $100 to $300 for parts and labor.

9. Can I reset the Check Engine light after fixing a P0138 code on my 2006 Nissan Maxima?

- Yes, you can reset the Check Engine light using an OBDII scanner after the issue causing the P0138 code has been addressed.

10. Will a P0138 code cause my 2006 Nissan Maxima to fail an emissions test?

- Yes, a P0138 code can cause your vehicle to fail an emissions test due to the high voltage readings from the HO2S12 sensor.

Discuss the causes and fixes for P0138 2006 Nissan Maxima OBDII Code

Submit a New Comment

  • my 2006 Nissan maxima I was stopped at a traffic light as stepped on gas the car did not increase movement it just move at about 8to 10mph it would not move any faster and the motor did not sound it was not increase when stepping on the gas. I was able to pull over and moved the gear shift and in reverse would move normal and the motor was sounding normal.so I tried in drive and it moved very slow and all the dash lights all came on. I was able to get home at a very speed then I put my OBD2 and gave a code O2 sensor circuit high voltage bank1 sensor 2 and PO138 then gave a code POO37 HO2sheater control1 circuit low bank 1 sensor 2.i just need to know if to take the transmission shop or to firestone store, they don't do transmission work.

    Reply to Comment

  • I recommend taking to your Maxima to a transmission shop. Neither of the codes you have will cause the symptoms you describe. Have you tried clearing the codes?

    Reply to Comment