BMW P1138 Code:O2 Sensor Heater Circuit Low Voltage Bank 1 Sensor 2
As a BMW owner, it’s important to stay informed about any potential issues that may arise with your vehicle. One common problem that you may encounter is the P1138 diagnostic trouble code (DTC). This code can indicate a variety of issues related to the O2 sensor heater circuit in your BMW. In this article, we’ll explore the meaning, causes, symptoms, and fixes for the BMW P1138 code, so you can get your vehicle back on the road in no time.
BMW P1138 Code: Meaning, Causes, Symptoms and Fixes
The BMW P1138 code is a diagnostic trouble code (DTC) that indicates an issue with the O2 sensor heater circuit in bank 1 sensor 2. This code is triggered when the voltage in the O2 sensor heater circuit is lower than the expected range. The O2 sensor is responsible for measuring the amount of oxygen in the exhaust gases and providing feedback to the engine control module (ECM) to adjust the air-fuel ratio. A malfunctioning O2 sensor can cause poor fuel economy, reduced engine performance, and increased emissions. The causes of the P1138 code can include a faulty O2 sensor, damaged wiring or connectors, or a failed ECM. Symptoms of this code may include a check engine light, rough idling, and decreased acceleration. To fix the issue, the faulty component must be identified and replaced or repaired. It is recommended to seek the assistance of a professional mechanic to diagnose and fix the problem.
Signs and Symptoms of BMW P1138 Code
When the BMW P1138 code appears, it indicates that there is a problem with the O2 sensor heater circuit low voltage bank 1 sensor 2. This can cause a range of symptoms that can affect the performance of your BMW. Here are some of the signs and symptoms that you may experience:
- Check Engine Light: The most common symptom of the P1138 code is the illumination of the check engine light on your BMW’s dashboard. This light will remain on until the issue is resolved.
- Poor Fuel Economy: A faulty O2 sensor can cause your BMW to consume more fuel than usual. This can result in poor fuel economy and increased expenses at the gas pump.
- Engine Misfires: If the O2 sensor is not functioning properly, it can cause the engine to misfire. This can lead to a rough idle, hesitation, and a lack of power when accelerating.
- Failed Emissions Test: A malfunctioning O2 sensor can cause your BMW to fail an emissions test. This can result in fines and the inability to register your vehicle until the issue is resolved.
- Reduced Performance: A faulty O2 sensor can cause your BMW to run poorly, resulting in reduced performance and a lack of power.
If you are experiencing any of these symptoms, it is important to have your BMW inspected by a qualified mechanic. They can diagnose the issue and recommend the appropriate repairs to get your BMW back on the road. Ignoring the P1138 code can lead to further damage to your vehicle and increased repair costs.
Possible Causes of BMW P1138 Code
The P1138 code in BMW vehicles indicates an issue with the O2 sensor heater circuit low voltage bank 1 sensor 2. This code can be triggered due to various reasons, including:
- Faulty O2 Sensor: A faulty or damaged O2 sensor can cause the P1138 code to appear. The sensor may not be able to detect the correct amount of oxygen in the exhaust, leading to low voltage in the heater circuit.
- Wiring Issues: Damaged or corroded wiring in the O2 sensor heater circuit can also cause the P1138 code. This can lead to low voltage in the circuit, preventing the sensor from functioning correctly.
- Faulty PCM: The Powertrain Control Module (PCM) is responsible for controlling the O2 sensor heater circuit. If the PCM is faulty, it may not be able to provide the correct voltage to the circuit, leading to the P1138 code.
- Failed Heater Circuit: The O2 sensor heater circuit may fail due to a blown fuse or a damaged relay. This can cause low voltage in the circuit, leading to the P1138 code.
- Exhaust Leak: An exhaust leak can cause the O2 sensor to detect an incorrect amount of oxygen in the exhaust, leading to low voltage in the heater circuit and triggering the P1138 code.
- Failed Catalytic Converter: A failed catalytic converter can cause the O2 sensor to detect an incorrect amount of oxygen in the exhaust, leading to low voltage in the heater circuit and triggering the P1138 code.
It is essential to diagnose the root cause of the P1138 code to fix the issue correctly. A professional mechanic can use a scan tool to read the code and perform further tests to determine the cause of the problem. Once the cause is identified, the mechanic can recommend the appropriate repairs to fix the issue and get your BMW back on the road.
Fixes for BMW P1138 Code
If you are experiencing the P1138 code in your BMW, it is important to address the issue promptly to avoid further damage to your vehicle. Here are some potential fixes for the P1138 code:
1. Replace the faulty O2 sensor
The P1138 code is often caused by a faulty oxygen (O2) sensor. This sensor is responsible for measuring the amount of oxygen in the exhaust gases and sending this information to the engine control module (ECM). If the sensor is not functioning properly, it can cause the ECM to receive incorrect data, leading to the P1138 code. Replacing the faulty O2 sensor can often resolve the issue.
2. Check the wiring and connections
Sometimes, the P1138 code can be caused by damaged or corroded wiring or connections in the O2 sensor circuit. Inspect the wiring and connections for any signs of damage or corrosion and repair or replace as necessary.
3. Replace the ECM
In rare cases, the P1138 code may be caused by a malfunctioning ECM. If all other potential causes have been ruled out, replacing the ECM may be necessary to resolve the issue.
4. Clear the code
After addressing the underlying issue causing the P1138 code, it is important to clear the code from the ECM’s memory. This can be done using a diagnostic tool or by disconnecting the battery for a few minutes.
5. Preventative maintenance
To prevent the P1138 code from occurring in the future, it is important to perform regular preventative maintenance on your BMW. This includes regular oil changes, air filter replacements, and spark plug replacements. Additionally, using high-quality fuel and keeping your vehicle’s engine clean can help prevent issues with the O2 sensor and other components.
In conclusion, the P1138 code in your BMW can be caused by a variety of issues, but with proper diagnosis and repair, it can be resolved. Whether it’s replacing a faulty O2 sensor, checking wiring and connections, or performing preventative maintenance, taking care of your vehicle can help keep it running smoothly.
How Much Will It Take to Fix BMW P1138 Code?
The cost of fixing the BMW P1138 code can vary depending on the severity of the issue and the type of repair needed. In general, the cost can range from $100 to $500 or more. The cost can be higher if the problem requires replacing the oxygen sensor or the catalytic converter.
The first step in fixing the P1138 code is to diagnose the problem. This can be done by using an OBD-II scanner to read the code and determine the cause of the issue. Once the problem has been identified, the repair process can begin.
If the issue is related to a faulty oxygen sensor, the cost of replacing the sensor can range from $100 to $300. If the catalytic converter needs to be replaced, the cost can be significantly higher, ranging from $500 to $2000 or more.
It is important to address the P1138 code as soon as possible to prevent further damage to your BMW’s engine and emissions system. Ignoring the issue can lead to decreased fuel efficiency, reduced engine performance, and potential damage to other components of your vehicle.
Overall, the cost of fixing the BMW P1138 code can vary depending on the severity of the issue and the type of repair needed. It is recommended to consult with a certified mechanic to determine the best course of action and estimate the cost of repairs.
Possible Causes and Fixes of Code
| Possible Cause | Fix | Cost to Fix |
|---|---|---|
| Failed O2 sensor heater circuit | Replace O2 sensor | $100-$300 |
| Wiring issues in O2 sensor heater circuit | Repair or replace wiring | $100-$500 |
| Failed PCM (Powertrain Control Module) | Replace PCM | $500-$1000 |
| Failed fuse or relay in O2 sensor heater circuit | Replace fuse or relay | $10-$50 |
Preventing BMW P1138 Code
The BMW P1138 code is a common issue that can cause problems with the performance of your vehicle. However, there are several preventive measures that you can take to avoid this problem. Here are some of the most effective ways to prevent the BMW P1138 code:
1. Regular Maintenance: Regular maintenance is the key to preventing the BMW P1138 code. Make sure to follow the manufacturer’s recommended maintenance schedule and have your vehicle serviced regularly. This will help to keep your vehicle in good condition and prevent any issues from occurring.
2. Check Engine Light: If your check engine light comes on, it is important to have it checked out as soon as possible. Ignoring the warning signs can lead to more serious problems down the road. A professional mechanic can diagnose the issue and fix it before it becomes a major problem.
3. Replace Faulty O2 Sensors: The P1138 code is often caused by a faulty O2 sensor. If you notice any symptoms of a bad O2 sensor, such as poor fuel economy or rough idling, it is important to have it replaced as soon as possible. This will prevent the code from occurring and improve the overall performance of your vehicle.
4. Use High-Quality Fuel: Using high-quality fuel can help to prevent the P1138 code. Low-quality fuel can cause damage to your engine and lead to a variety of issues, including the P1138 code. Make sure to use fuel that meets the manufacturer’s recommended specifications.
5. Avoid Overheating: Overheating can cause a variety of issues with your vehicle, including the P1138 code. Make sure to keep your engine cool by checking the coolant levels regularly and avoiding driving in extreme temperatures.
- Conclusion:
In conclusion, the BMW P1138 code can be prevented by following these simple preventive measures. Regular maintenance, checking the engine light, replacing faulty O2 sensors, using high-quality fuel, and avoiding overheating are all effective ways to prevent this issue. By taking these steps, you can keep your BMW running smoothly and avoid any costly repairs down the road.
How Serious is the BMW P1138 Code?
The BMW P1138 code is a diagnostic trouble code that indicates a problem with the O2 sensor heater circuit in bank 1 sensor 2. This code is not considered to be a serious issue, but it can affect the performance of your BMW and cause it to fail an emissions test.
The O2 sensor is responsible for monitoring the amount of oxygen in the exhaust gases and sending this information to the engine control module (ECM). The ECM uses this information to adjust the air/fuel ratio and ensure that the engine is running efficiently. If the O2 sensor heater circuit is not functioning properly, it can cause the sensor to take longer to reach operating temperature, which can result in inaccurate readings and poor engine performance.
While the P1138 code is not a serious issue, it should be addressed as soon as possible to prevent further damage to your BMW. If left untreated, it can lead to more serious problems and potentially cause damage to other components of the engine. It is recommended to have your BMW diagnosed by a professional mechanic to determine the exact cause of the code and to ensure that it is repaired correctly.
Can You Still Drive with the BMW P1138 Code?
If your BMW has triggered the P1138 code, it means that there is an issue with the O2 sensor heater circuit in bank 1 sensor 2. This can cause a variety of symptoms, including poor fuel economy, rough idling, and decreased engine performance. However, the question remains: can you still drive your BMW with the P1138 code?
The answer is that it depends on the severity of the issue. If the code has just been triggered and you are not experiencing any noticeable symptoms, you may be able to continue driving your BMW for a short period of time. However, it is important to address the issue as soon as possible to prevent further damage to your vehicle.
If you are experiencing symptoms such as decreased performance or rough idling, it is recommended that you do not drive your BMW until the issue has been resolved. Continuing to drive with the P1138 code can cause further damage to your vehicle and potentially lead to more expensive repairs down the line.
In summary, while you may be able to drive your BMW with the P1138 code for a short period of time, it is important to address the issue as soon as possible to prevent further damage to your vehicle and ensure optimal performance.
Conclusion
If you are experiencing the P1138 code in your BMW, it is important to address the issue promptly to avoid further damage to your vehicle. The code indicates a problem with the O2 sensor heater circuit, which can lead to decreased fuel efficiency and engine performance. The most common causes of the P1138 code include a faulty O2 sensor, damaged wiring, or a malfunctioning PCM. To fix the issue, you may need to replace the O2 sensor or repair any damaged wiring. It is recommended to consult with a professional mechanic to properly diagnose and fix the problem. By addressing the P1138 code, you can ensure your BMW is running smoothly and efficiently on the road.
FAQ
What does the BMW P1138 code mean?
The BMW P1138 code refers to an O2 sensor heater circuit low voltage in bank 1 sensor 2.
What are the causes of the BMW P1138 code?
The causes of the BMW P1138 code can include a faulty O2 sensor, damaged wiring or connectors, a blown fuse, or a malfunctioning PCM.
What are the symptoms of the BMW P1138 code?
The symptoms of the BMW P1138 code can include decreased fuel efficiency, rough idling, and a decrease in engine performance.
Can I still drive my BMW with the P1138 code?
It is not recommended to drive your BMW with the P1138 code as it can cause damage to your engine and decrease fuel efficiency.
How do I diagnose the BMW P1138 code?
The BMW P1138 code can be diagnosed using an OBD-II scanner to read the code and determine the cause of the issue.
How do I fix the BMW P1138 code?
The fix for the BMW P1138 code can vary depending on the cause of the issue. It may involve replacing the O2 sensor, repairing damaged wiring or connectors, replacing a blown fuse, or repairing a malfunctioning PCM.
Can I fix the BMW P1138 code myself?
While it is possible to fix the BMW P1138 code yourself, it is recommended to seek the assistance of a professional mechanic to ensure the issue is properly diagnosed and repaired.
Learn about other similar BMW Fault Codes from our BMW OBD 2 Fault Code List.