Quick Answer
U0685 means: U0685 indicates a communication error between vehicle control modules, affecting performance.
Can I drive with U0685? Immediate attention required to prevent further issues.
Common Questions
What does U0685 mean and how does it affect my car?
U0685 indicates a communication issue between your vehicle's control modules. This can lead to erratic performance, such as engine hesitation, malfunctioning electronic features, and potential starting issues. Addressing this promptly is essential to maintain vehicle safety and efficiency.
What are the most common causes of U0685 and how much does it cost to fix?
Common causes include damaged wiring (50% chance), faulty control modules (30% chance), and poor connections. Repair costs can range from $150 for wiring repair to $1200 for module replacement, depending on the issue.
Can I drive my car with U0685 or should I stop immediately?
It's advisable to avoid driving your car until the issue is diagnosed and resolved. Driving with U0685 can lead to further complications, including complete system failures.
How can I diagnose U0685 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for diagnostic trouble codes, retrieve freeze frame data, and monitor live sensor readings. This will help you understand the context of the U0685 code and guide you in troubleshooting.
What vehicles are most commonly affected by U0685?
The U0685 code is commonly seen in 2015-2020 Ford F-Series trucks, but it can also affect other models across various manufacturers. Always check for specific recalls or technical service bulletins related to your vehicle.
How can I prevent U0685 from happening again?
Regular maintenance, including inspecting wiring and connections, can help prevent U0685. Additionally, keeping your vehicle's software updated and addressing electrical issues promptly will also reduce the risk.
What is U0685?
The diagnostic trouble code U0685 indicates a communication error between various control modules in your vehicle. Specifically, this code points to a failure in the communication link of the vehicle's network, which can involve several systems, including the engine control unit (ECU), transmission control unit (TCU), and body control module (BCM). When the U0685 code is triggered, it often results from issues like damaged wiring, poor connections, or faulty modules. In practical terms, this means your vehicle may experience erratic behavior, such as inconsistent engine performance, failure of certain electronic features, or even the inability to start. The impact of this code can vary significantly; some drivers report only minor inconveniences, while others might face significant operational difficulties. It's crucial to address this issue promptly, as ignoring it could lead to further electrical system problems or even complete vehicle failure. Regular diagnostics using tools like the GeekOBD APP can help uncover the root cause and prevent major issues down the line.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0685 is present:
- The check engine light remains illuminated, indicating a persistent issue with the vehicle's communication systems.
- Unresponsive electronic features, such as power windows or locking mechanisms, might fail to work as intended, affecting driver convenience.
- Drivers may notice the engine hesitating during acceleration, which can feel like a lack of power or responsiveness when pressing the gas pedal.
- Inconsistent performance of the vehicle's transmission, leading to rough shifting or unexpected gear changes.
- Fuel economy can decrease by 10-15% as the engine may not operate efficiently without proper communication between modules.
Possible Causes
Most common causes of U0685 (ordered by frequency):
- A damaged wiring harness or connector, which accounts for about 50% of U0685 cases. This can happen due to wear and tear, exposure to moisture, or physical damage.
- Faulty control module or electronic component, representing around 30% of cases. When these components fail, they often disrupt the communication network.
- Poor ground connections or loose connectors, which can lead to intermittent communication failures. Regular inspections can help prevent this.
- Less common issues include software glitches in the control modules, which may require a software update to resolve.
- Rarely, a complete failure of the vehicle's communication network can occur, which might necessitate extensive repairs or part replacements.
U0685 Repair Costs
Cost Breakdown by Repair Type
Wiring and Connector Repair
Repair or replace damaged wiring and connectors to restore communication.
- Total: $150 - $500
- Success rate: 90%
Control Module Replacement
Replace faulty control modules that are causing the communication failure.
- Total: $500 - $1200
- Success rate: 95%
Software Update
Update the software of the control modules to fix glitches.
- Total: $100 - $300
- Success rate: 80%
Money-Saving Tips for U0685
- 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 U0685 Diagnosis Process
Follow these systematic steps to accurately diagnose U0685. 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 a multimeter or specific diagnostic tools to test suspected components (20-30 minutes)
Step 3: Component testing - Use a 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 the vehicle under various conditions to confirm repair success (15-20 minutes)
Step 5: Road test verification - Drive the 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: 2017 Ford F-150 Communication Error
Vehicle: 2017 Ford F-150, 80,000 miles
Problem: Customer reported check engine light on and intermittent power loss.
Diagnosis: Initial scan revealed U0685. Inspected wiring harness and found a damaged connector.
Solution: Replaced damaged connector and repaired wiring. Cleared codes and verified operation.
Cost: $250
Result: Customer reported no further issues, and vehicle performance returned to normal.
Case Study 2: 2019 Ford Explorer Module Replacement
Vehicle: 2019 Ford Explorer, 50,000 miles
Problem: Vehicle would not start, and multiple warning lights were illuminated.
Diagnosis: Scan indicated U0685. Tests revealed a faulty body control module.
Solution: Replaced body control module and updated software.
Cost: $950
Result: Vehicle started reliably post-repair, and all systems functioned correctly.