P0138 BMW Code - O2 Sensor Circuit High Voltage Bank 1 Sensor 2
Quick Answer
The Heated Oxygen Sensor 2 (HO2S) (Rear O2 Sensor), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 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
- P0138 BMW indicates O2 Sensor Circuit High Voltage Bank 1 Sensor 2.
- Common causes
- Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 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.
Code P0138 BMW Description
What are the Possible Causes of the DTC P0138 BMW?
- Faulty Rear Heated Oxygen Sensor Bank 1
- Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Intake air leaks
- Exhaust gas leaks
- Inappropriate fuel pressure
- Faulty fuel injectors
How to Fix the DTC P0138 BMW?
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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0138 BMW 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 P0138 BMW code?
Need more information on how to fix the P0138 BMW code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0138 BMW code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0138 BMW Code
1. What are common symptoms of OBDII code P0138 in a BMW?
- Common symptoms include decreased fuel efficiency, rough idling, engine misfires, and the illumination of the check engine light.
2. What does the OBDII code P0138 "O2 Sensor Circuit High Voltage Bank 1 Sensor 2" mean for a BMW?
- This code indicates that the oxygen sensor downstream of the catalytic converter in bank 1 is detecting a high voltage condition.
3. What are the possible causes of OBDII code P0138 in a BMW?
- Possible causes include a faulty oxygen sensor, wiring issues in the O2 sensor circuit, a vacuum leak, exhaust system leaks, or a malfunctioning catalytic converter.
4. How can I diagnose the O2 sensor circuit high voltage issue in my BMW?
- Diagnosis typically involves checking the voltage output of the oxygen sensor using a multimeter, inspecting the wiring for any damage, and checking for any leaks in the exhaust system.
5. Can driving with OBDII code P0138 cause further damage to my BMW?
- Continuing to drive with this code may lead to decreased fuel efficiency, potential damage to the catalytic converter, and increased emissions.
6. How can I repair OBDII code P0138 in my BMW?
- Repair options may include replacing the oxygen sensor, repairing any damaged wiring, fixing vacuum or exhaust leaks, or replacing the catalytic converter if necessary.
7. Is it safe to drive my BMW with the check engine light on due to code P0138?
- It is generally safe to drive the vehicle for a short period with the check engine light on, but it is recommended to have the issue diagnosed and repaired as soon as possible to prevent further damage.
8. Can I reset the OBDII code P0138 in my BMW with a simple scan tool?
- While you can reset the code with a scan tool, it is important to address the underlying issue causing the code to prevent it from coming back.
9. How much does it typically cost to repair OBDII code P0138 in a BMW?
- The cost of repairs can vary depending on the exact cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.
10. How long does it take to fix OBDII code P0138 in a BMW?
- The repair time can vary based on the specific cause of the code, but it usually takes a few hours to a full day for diagnosis and repair.
Discuss the causes and fixes for P0138 BMW OBDII Code
Code P0138 BMW comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
