Quick Answer
U0820 means: DTC U0820 indicates a communication error between control modules in your vehicle.
Can I drive with U0820? Immediate attention is recommended to prevent further issues.
Common Questions
What does U0820 mean and how does it affect my car?
DTC U0820 indicates a communication error between the Body Control Module and other modules. This can lead to various electrical problems, impacting features such as power locks, windows, or even affecting engine performance. It's crucial to address this issue promptly to maintain vehicle functionality.
What are the most common causes of U0820 and how much does it cost to fix?
Common causes include a defective Body Control Module, damaged wiring, and software issues. Repair costs for BCM replacement can range from $300 to $800, while wiring repairs generally cost between $100 and $300.
Can I drive my car with U0820 or should I stop immediately?
While it may be possible to drive short distances, it is not recommended to ignore U0820 as it can lead to more severe electrical problems. Immediate inspection is advisable.
How can I diagnose U0820 myself using GeekOBD APP?
You can use the GeekOBD APP to scan for codes and view freeze frame data. Look for any communication errors, inspect wiring visually, and use the app to monitor module functionality.
What vehicles are most commonly affected by U0820?
Commonly affected vehicles include the 2015-2018 Ford Explorer, 2016-2019 Ford Fusion, and various models from General Motors, particularly those with advanced electrical systems.
How can I prevent U0820 from happening again?
Regularly inspect wiring and connectors for wear, keep your vehicle's electrical system maintained, and address any electrical issues promptly to prevent future occurrences.
What is U0820?
DTC U0820 is a diagnostic trouble code indicating a communication issue between the vehicle's control modules. Specifically, this code points to a malfunction in the communication between the vehicle's Body Control Module (BCM) and another control unit, such as the Powertrain Control Module (PCM) or the Transmission Control Module (TCM). This issue can lead to a variety of problems, including erratic vehicle behavior, failure of electrical components, or even an inability to start the vehicle. For car owners, this means that if you see U0820, it's crucial to address it promptly to prevent further complications. Commonly found in vehicles like the 2015-2018 Ford Explorer, this code may trigger warning lights on the dashboard, and you might notice symptoms like strange electrical behavior or non-functional features like power windows or door locks. Ignoring this code can lead to more severe electrical issues, ultimately affecting vehicle safety and performance. Therefore, understanding and addressing U0820 is paramount for any vehicle owner.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0820 is present:
- The check engine light remains illuminated continuously, indicating a fault that needs attention.
- You experience intermittent electrical failures, such as power windows or central locking not working properly.
- The vehicle may occasionally hesitate during acceleration, possibly due to communication issues affecting engine performance.
- You may notice a decrease in fuel efficiency, with reports showing up to 10-15% lower mileage.
- Dashboard warning lights may flicker or behave erratically, suggesting deeper electrical system problems.
Possible Causes
Most common causes of U0820 (ordered by frequency):
- The most common cause of U0820 is a defective Body Control Module (BCM), which has a likelihood of about 50%. This can occur due to age or exposure to moisture.
- Another common cause is damaged wiring or connectors between the BCM and other control modules, which can result from wear and tear or physical damage.
- Faulty software or programming issues in the BCM could lead to communication failures, which is a less common cause but still significant.
- A less common but serious cause could be a failing battery or alternator, which affects the power supply to electronic modules.
- In rare cases, a complete control module failure might occur, requiring replacement of the affected module.
U0820 Repair Costs
Cost Breakdown by Repair Type
BCM Replacement
Replacing the Body Control Module is often necessary if it is found to be defective during diagnostics.
- Total: $300 - $800
- Success rate: 90%
Wiring Repair
Repairing damaged wiring or connectors can resolve communication issues without the need for module replacement.
- Total: $100 - $300
- Success rate: 85%
Money-Saving Tips for U0820
- Start with the most common and least expensive repairs first
- Use GeekOBD APP to confirm diagnosis before replacing expensive parts
- Consider preventive maintenance to avoid future occurrences
- Compare prices for OEM vs aftermarket parts based on your needs
- Address the issue promptly to prevent more expensive secondary damage
Diagnostic Steps
Professional U0820 Diagnosis Process
Follow these systematic steps to accurately diagnose U0820. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Start with an initial visual inspection to look for any obvious signs of damage, such as frayed wires, loose connections, or corrosion on connectors (5-10 minutes)
Step 1: Start with an initial visual inspection to look for any obvious signs of damage, such as frayed wires, loose connections, or corrosion on connectors (5-10 minutes).
Step 2: Step 2: Use the GeekOBD APP to perform an OBD2 scan; retrieve all codes, including freeze frame data to understand the fault context (10-15 minutes)
Step 2: Use the GeekOBD APP to perform an OBD2 scan; retrieve all codes, including freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Conduct component testing using a multimeter or specific diagnostic tools to test suspected components like the BCM or wiring harness (20-30 minutes)
Step 3: Conduct component testing using a multimeter or specific diagnostic tools to test suspected components like the BCM or wiring harness (20-30 minutes).
Step 4: Step 4: After repairs are made, carry out a system function test to verify proper operation and clear any codes present (10-15 minutes)
Step 4: After repairs are made, carry out a system function test to verify proper operation and clear any codes present (10-15 minutes).
Step 5: Step 5: Finish with a road test under various conditions to confirm that the repair has resolved the issue (15-20 minutes)
Step 5: Finish with a road test under various conditions to confirm that the repair has resolved the issue (15-20 minutes).
Important Notes
- Always verify the repair with GeekOBD APP after completing diagnostic steps
- Clear codes and test drive to ensure the problem is resolved
- Address underlying causes to prevent code recurrence
Real Repair Case Studies
Case Study 1: 2016 Ford Explorer BCM Replacement
Vehicle: 2016 Ford Explorer, 65,000 miles
Problem: Customer reported intermittent power windows and check engine light on.
Diagnosis: Diagnostic scan revealed U0820 code, leading to a focus on the Body Control Module and associated wiring.
Solution: Replaced the defective BCM and repaired damaged wiring.
Cost: $600 (BCM $500, labor $100)
Result: All electrical features restored, and no further codes appeared after testing.
Case Study 2: 2017 Chevrolet Malibu Wiring Repair
Vehicle: 2017 Chevrolet Malibu, 45,000 miles
Problem: Vehicle experienced power lock failures and dashboard warning lights.
Diagnosis: OBD2 scan showed U0820; inspection revealed frayed wiring near the BCM.
Solution: Repaired wiring and secured connections.
Cost: $150 (labor and parts included)
Result: Restored functionality of locks and cleared codes after testing.