BMW P0686 Code:Engine Control Module Power Relay Control Circuit Low
As a car owner, it can be frustrating to see a warning light pop up on your dashboard. One of the most common issues that BMW drivers face is the P0686 code. This diagnostic trouble code (DTC) is related to the engine control module power relay control circuit low. If you’re experiencing this problem, don’t worry – we’re here to help. In this article, we’ll discuss the meaning, causes, symptoms, and fixes for the BMW P0686 code. We’ll also provide expert advice on troubleshooting and finding reliable mechanics to help you resolve the issue. So, let’s dive in and get your BMW back on the road!
What Does the BMW P0686 Code Mean?
The BMW P0686 code is a diagnostic trouble code (DTC) that indicates a problem with the engine control module (ECM) power relay control circuit. This code is triggered when the ECM detects a low voltage or resistance in the power relay control circuit. The power relay control circuit is responsible for controlling the power supply to the ECM, which is essential for the proper functioning of the engine. When this circuit is compromised, it can lead to a range of issues, including poor engine performance, reduced fuel efficiency, and even engine stalling. It is important to address this issue promptly to avoid further damage to the vehicle.
Signs and Symptoms of BMW P0686 Code
When the engine control module power relay control circuit in a BMW vehicle experiences a low voltage condition, it triggers the diagnostic trouble code P0686. This code can cause a range of symptoms that can affect the performance and drivability of the vehicle. Here are some of the signs and symptoms of the BMW P0686 code:
- Check Engine Light: The most common symptom of the P0686 code is the illumination of the check engine light on the dashboard. This light indicates that there is a problem with the engine control module power relay control circuit.
- Engine Stalling: Another common symptom of the P0686 code is engine stalling. The engine may suddenly shut off while driving, which can be dangerous if it happens at high speeds or in heavy traffic.
- Difficulty Starting: The engine may have difficulty starting or may not start at all when the P0686 code is present. This can be frustrating and may require multiple attempts to get the engine to turn over.
- Reduced Power: The vehicle may experience reduced power when the P0686 code is present. This can make it difficult to accelerate or maintain speed, especially when driving uphill or towing a heavy load.
- Poor Fuel Economy: The P0686 code can also cause poor fuel economy, as the engine may not be running efficiently. This can result in higher fuel costs over time.
If you experience any of these symptoms in your BMW vehicle, it is important to have it diagnosed and repaired as soon as possible. Ignoring the P0686 code can lead to further damage to the engine or other components, which can be costly to repair. A qualified mechanic can help you troubleshoot the problem and find a reliable solution to get your BMW back on the road.
Possible Causes of BMW P0686 Code
The P0686 code is a generic powertrain code that indicates a problem with the engine control module (ECM) power relay control circuit. This code is specific to BMW vehicles and can be triggered by a variety of issues. Here are some of the possible causes of the P0686 code:
- Failed ECM power relay: The most common cause of the P0686 code is a failed ECM power relay. This relay is responsible for providing power to the ECM, and if it fails, the ECM will not function properly.
- Wiring issues: Another possible cause of the P0686 code is wiring issues in the ECM power relay control circuit. This can include damaged or corroded wires, loose connections, or a short circuit.
- Failed ECM: In some cases, the ECM itself may be the problem. If the ECM has failed, it may not be able to receive power from the power relay, which can trigger the P0686 code.
- Failed battery: A weak or dead battery can also cause the P0686 code to appear. If the battery is not providing enough power to the ECM, it may not be able to function properly.
- Failed alternator: Similarly, a failed alternator can also cause the P0686 code. If the alternator is not charging the battery properly, the battery may not be able to provide enough power to the ECM.
- Failed starter: Finally, a failed starter can also cause the P0686 code. If the starter is not working properly, it may not be able to provide enough power to the ECM to start the engine.
If you are experiencing the P0686 code, it is important to have your vehicle diagnosed by a qualified mechanic. They will be able to determine the exact cause of the code and recommend the appropriate repairs. Ignoring the P0686 code can lead to further damage to your vehicle and potentially costly repairs down the line.
Fixes for BMW P0686 Code
The P0686 code in BMW vehicles indicates a problem with the engine control module power relay control circuit. This can cause various issues, including engine misfires, reduced power, and even stalling. Fortunately, there are several fixes that can help resolve this issue.
1. Check the power relay
The first step in fixing the P0686 code is to check the power relay. This component is responsible for supplying power to the engine control module. If it is faulty, it can cause the code to appear. Check the relay for any signs of damage or wear and replace it if necessary.
2. Inspect the wiring
Another common cause of the P0686 code is damaged or corroded wiring. Inspect the wiring harness for any signs of damage, such as frayed or broken wires. If any issues are found, repair or replace the wiring as needed.
3. Check the battery
A weak or dead battery can also cause the P0686 code to appear. Check the battery voltage and ensure that it is within the manufacturer’s recommended range. If the battery is low, recharge or replace it.
4. Replace the engine control module
If all other fixes have been attempted and the P0686 code still appears, it may be necessary to replace the engine control module. This component is responsible for controlling various engine functions, and a faulty module can cause a range of issues.
5. Seek professional help
If you are unsure about how to fix the P0686 code or do not have the necessary tools or expertise, it is best to seek professional help. A qualified mechanic can diagnose the issue and recommend the best course of action to fix it.
In conclusion, the P0686 code in BMW vehicles can be caused by various issues, including a faulty power relay, damaged wiring, a weak battery, or a faulty engine control module. By checking these components and seeking professional help if needed, you can resolve the issue and get your BMW back on the road.
How Much Will It Take to Fix BMW P0686 Code?
The cost of fixing the BMW P0686 code can vary depending on the root cause of the problem. The code indicates that there is an issue with the engine control module power relay control circuit, which can lead to a range of symptoms such as engine misfires, stalling, and poor performance.
The first step in fixing the code is to diagnose the problem accurately. This may involve using specialized diagnostic tools to identify the exact cause of the issue. Once the problem has been identified, the cost of fixing it will depend on the severity of the issue and the parts that need to be replaced.
In some cases, fixing the BMW P0686 code may be as simple as replacing a faulty relay or fuse. However, if the issue is more severe, it may require replacing the entire engine control module, which can be a costly repair.
It is recommended to take your BMW to a certified mechanic who has experience working with BMW vehicles. They will be able to diagnose the problem accurately and provide you with an estimate of the cost of repairs.
Possible Causes and Fixes of Code
| Possible Cause | Fix | Cost to Fix |
|---|---|---|
| Faulty Engine Control Module (ECM) | Replace the ECM | $500-$1000 |
| Defective Power Relay | Replace the power relay | $50-$200 |
| Loose or corroded wiring connections | Check and repair wiring connections | $100-$300 |
| Failed battery or alternator | Replace the battery or alternator | $100-$500 |
| Malfunctioning starter motor | Replace the starter motor | $200-$500 |
Preventing BMW P0686 Code
The BMW P0686 code is a common issue that can be prevented by taking some preventive measures. Here are some tips to help you prevent this code from appearing:
- Regular Maintenance: Regular maintenance of your BMW vehicle is essential to prevent any issues. Make sure to follow the manufacturer’s recommended maintenance schedule and get your vehicle serviced regularly.
- Check the Battery: A weak or faulty battery can cause the P0686 code to appear. Make sure to check your battery regularly and replace it if necessary.
- Inspect the Wiring: Check the wiring and connections in your vehicle’s engine control module power relay control circuit. Look for any signs of damage, corrosion, or loose connections. If you find any issues, get them fixed immediately.
- Use Quality Parts: Always use quality parts when repairing or replacing any components in your BMW vehicle. Cheap or low-quality parts can cause issues and lead to the P0686 code appearing.
- Drive Carefully: Avoid aggressive driving and sudden stops or starts. This can put a strain on your vehicle’s electrical system and cause issues.
By following these preventive measures, you can reduce the risk of the P0686 code appearing in your BMW vehicle. Regular maintenance, checking the battery and wiring, using quality parts, and driving carefully are all essential to keep your vehicle running smoothly and prevent any issues. If you do experience the P0686 code, it’s important to get it diagnosed and fixed by a qualified mechanic to prevent any further damage to your vehicle.
How Serious is the BMW P0686 Code?
The BMW P0686 code is a serious issue that should not be ignored. This code indicates that there is a problem with the engine control module power relay control circuit, which can cause a variety of issues with the vehicle’s performance and safety.
One of the most significant symptoms of the P0686 code is that the engine may not start or may stall while driving. This can be dangerous, especially if it happens while driving at high speeds or in heavy traffic. Additionally, the code can cause the vehicle to run poorly, with reduced power and acceleration, and increased fuel consumption.
The causes of the P0686 code can vary, but they are typically related to issues with the power relay control circuit, such as a faulty relay, damaged wiring, or a malfunctioning engine control module. These issues can be difficult to diagnose and repair, and may require the help of a professional mechanic.
If you are experiencing symptoms of the P0686 code, it is important to have your vehicle inspected as soon as possible. Ignoring the issue can lead to further damage to your vehicle and potentially dangerous driving conditions.
Can You Still Drive with the BMW P0686 Code?
If your BMW is showing the P0686 code, it means that there is an issue with the engine control module power relay control circuit. This can cause a variety of symptoms, including engine misfires, stalling, and reduced power. However, the question remains: can you still drive your BMW with this code?
The answer is that it depends on the severity of the issue. If your BMW is experiencing severe symptoms, such as stalling or reduced power, it is not safe to drive. Continuing to drive your vehicle in this condition can cause further damage to the engine and other components, and may even put you at risk of an accident.
However, if your BMW is only experiencing minor symptoms, such as a check engine light or a slight decrease in performance, it may be safe to drive for a short period of time. However, it is important to address the issue as soon as possible to prevent further damage and ensure the safety of yourself and others on the road.
In any case, it is always recommended to have your BMW inspected by a qualified mechanic as soon as possible if you are experiencing any issues with your vehicle. They can diagnose the issue and provide you with the necessary repairs to get your BMW back on the road safely.
Conclusion
In conclusion, the BMW P0686 code is a common issue that BMW owners may encounter. It indicates a problem with the engine control module power relay control circuit, which can cause various symptoms such as engine stalling, poor performance, and reduced fuel efficiency. The causes of the code can range from a faulty relay to a damaged wiring harness, and the fixes may involve replacing the relay, repairing the wiring, or updating the software. If you are experiencing the P0686 code, it is recommended to seek professional help from a certified mechanic who has experience working with BMW vehicles. By following the advice and tips provided in this article, you can better understand the BMW P0686 code and take the necessary steps to resolve the issue.
FAQ
What does the BMW P0686 code mean?
The BMW P0686 code refers to a problem with the engine control module power relay control circuit. This means that there is an issue with the circuit that controls the power relay for the engine control module.
What are the symptoms of the BMW P0686 code?
The symptoms of the BMW P0686 code may include a check engine light, reduced engine power, and difficulty starting the vehicle.
What are the possible causes of the BMW P0686 code?
The possible causes of the BMW P0686 code may include a faulty power relay, a damaged wiring harness, a malfunctioning engine control module, or a blown fuse.
How is the BMW P0686 code diagnosed?
The BMW P0686 code can be diagnosed using an OBD-II scanner, which will read the code and provide information about the problem. A mechanic may also perform a visual inspection of the wiring and components related to the power relay control circuit.
Can I still drive my BMW with the P0686 code?
It is not recommended to drive your BMW with the P0686 code, as it can cause further damage to the engine and other components. It is best to have the issue diagnosed and repaired as soon as possible.
How is the BMW P0686 code fixed?
The BMW P0686 code can be fixed by replacing the faulty power relay, repairing or replacing any damaged wiring, or replacing the engine control module if necessary.
How much does it cost to fix the BMW P0686 code?
The cost to fix the BMW P0686 code will vary depending on the cause of the problem and the extent of the repairs needed. It is best to get a quote from a trusted mechanic before proceeding with any repairs.
Learn about other similar BMW Fault Codes from our BMW OBD 2 Fault Code List.