Quick Answer
U0671 means: U0671 indicates a communication issue between vehicle control modules.
Can I drive with U0671? It's advisable to address this issue soon to avoid worsening electrical problems.
Common Questions
What does U0671 mean and how does it affect my car?
The U0671 code indicates a communication issue between critical vehicle control modules. This can lead to various electrical problems, affecting your vehicle's performance and safety. Immediate attention is recommended to prevent further complications.
What are the most common causes of U0671 and how much does it cost to fix?
Common causes include faulty wiring (60% likelihood), malfunctioning body control modules (20% likelihood), and poor ground connections (10% likelihood). Repair costs can range from $150 for wiring repairs to $800 for BCM replacements.
Can I drive my car with U0671 or should I stop immediately?
While you may be able to drive your car, it's advisable to address the U0671 code promptly. Ignoring it can lead to more severe electrical failures that may leave you stranded, especially in critical situations.
How can I diagnose U0671 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for DTCs, view freeze frame data, and check live sensor readings. Start by connecting the app to your OBD2 port, retrieve codes, and interpret the diagnostic information to identify specific issues.
What vehicles are most commonly affected by U0671?
U0671 is commonly reported in vehicles like the 2015-2020 Ford F-150 and 2017-2020 Chevrolet Silverado. Always refer to manufacturer recalls or TSBs for your specific model.
How can I prevent U0671 from happening again?
Regular maintenance, including electrical system checks, keeping wiring harnesses free from damage, and ensuring software updates are performed, can help prevent the recurrence of U0671.
What is U0671?
The diagnostic trouble code (DTC) U0671 indicates a communication error between the vehicle control module (VCM) and the body control module (BCM). This issue can arise from a variety of factors, including wiring problems, faulty connectors, or even a malfunctioning module itself. When your vehicle's computer systems cannot communicate effectively, various electrical systems may start to fail or behave erratically. This can lead to a range of operational issues, from minor inconveniences like non-functioning lights to more serious problems such as loss of vehicle power or even failure to start. It's important to understand that while this code might not cause immediate catastrophic failures, it can lead to a progressively worsening situation that could leave you stranded. Regular diagnostics using tools like the GeekOBD APP can help in identifying these issues early, preventing more expensive repairs down the line.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0671 is present:
- Check engine light stays on constantly, indicating a persistent issue that needs attention.
- Engine hesitates during acceleration, leading to a lack of responsiveness and potential safety risks.
- Fuel economy decreased by 10-15%, which could indicate underlying electrical issues affecting the engine performance.
- Interior lights flicker or fail to operate, indicating potential BCM issues.
- Non-functioning power windows or door locks, which can be frustrating and may indicate a broader electrical problem.
Possible Causes
Most common causes of U0671 (ordered by frequency):
- Faulty wiring or connectors (60% likelihood) - Damaged or corroded wires can disrupt communication.
- Malfunctioning body control module (20% likelihood) - A faulty BCM can prevent proper communication with the VCM.
- Poor ground connection (10% likelihood) - An inadequate ground can lead to electrical interference.
- Less common but serious cause: Control module software glitches - Updates may be required to fix communication issues.
- Rare but possible cause: Aftermarket modifications - Non-standard parts can interfere with vehicle electronics.
U0671 Repair Costs
Cost Breakdown by Repair Type
Wiring Repair
Repair or replace damaged wiring or connectors.
- Total: $150 - $400
- Success rate: 85%
Body Control Module Replacement
Replacing a faulty BCM with a new or refurbished unit.
- Total: $300 - $800
- Success rate: 90%
Software Update
Updating the vehicle's control module software to fix glitches.
- Total: $100 - $200
- Success rate: 70%
Money-Saving Tips for U0671
- 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 U0671 Diagnosis Process
Follow these systematic steps to accurately diagnose U0671. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Use multimeter or specific diagnostic tools to test suspected components (20-30 minutes)
Step 3: Component testing - Use multimeter or specific diagnostic tools to test suspected components (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes (10-15 minutes)
Step 4: System function test - Verify proper operation after repairs and clear codes (10-15 minutes).
Step 5: Step 5: Road test verification - Drive vehicle under various conditions to confirm repair success (15-20 minutes)
Step 5: Road test verification - Drive vehicle under various conditions to confirm repair success (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: Repair Case: 2017 Ford F-150 U0671
Vehicle: 2017 Ford F-150, 55,000 miles
Problem: Customer reported check engine light on and intermittent electrical issues.
Diagnosis: Initial scan revealed U0671 along with several other codes. A visual inspection showed frayed wiring in the harness.
Solution: Repaired the damaged wiring and cleared codes. Conducted a road test to confirm repair success.
Cost: $250
Result: Customer reported normal operation with no further issues.
Case Study 2: Repair Case: 2018 Chevrolet Silverado U0671
Vehicle: 2018 Chevrolet Silverado, 40,000 miles
Problem: Customer experienced power windows and door locks not functioning.
Diagnosis: OBD2 scan showed U0671. Testing confirmed a faulty BCM.
Solution: Replaced the BCM and reprogrammed to the vehicle. Conducted system tests post-repair.
Cost: $600
Result: All systems operational; customer satisfied with repair.