Quick Answer
U0668 means: DTC U0668 indicates a communication error between vehicle control modules.
Can I drive with U0668? Immediate attention is recommended to prevent potential vehicle issues.
Common Questions
What does U0668 mean and how does it affect my car?
DTC U0668 indicates that there is a communication breakdown between two or more control modules in your vehicle. This affects how your vehicle operates and can lead to symptoms like erratic dashboard lights and performance issues. If left unaddressed, it can cause significant problems, resulting in costly repairs.
What are the most common causes of U0668 and how much does it cost to fix?
The common causes of U0668 include faulty wiring or connectors (60% likelihood), control module failure (25%), and grounding issues (10%). Repair costs can vary widely; fixing wiring issues may cost between $150 and $400, while control module replacements can range from $500 to $1200.
Can I drive my car with U0668 or should I stop immediately?
It is not advisable to drive your car if the U0668 code is present. Driving with this code may lead to reduced performance, erratic behavior of vehicle systems, or even stalling. It's best to address the issue promptly to ensure safety and prevent further damage.
How can I diagnose U0668 myself using GeekOBD APP?
Using the GeekOBD APP, you can perform an OBD2 scan to retrieve diagnostic trouble codes. Look for U0668 and any additional codes that may provide context. The APP allows you to view freeze frame data, which can help identify when the issue occurred and under what conditions.
What vehicles are most commonly affected by U0668?
DTC U0668 is frequently seen in models like the 2016-2020 Ford Focus and the 2017-2021 Chevy Malibu. These vehicles have been reported to experience communication errors due to wiring issues and module failures.
How can I prevent U0668 from happening again?
Regular maintenance is key to preventing DTC U0668. Check wiring and connectors during routine services and avoid installing aftermarket electrical components unless professionally recommended. Keeping your vehicle's software updated can also help prevent communication issues.
What is U0668?
DTC U0668 signifies a communication error between various modules in your vehicle's network, typically the body control module (BCM) and another control unit. When this code is triggered, it indicates that the modules are unable to communicate properly, which can lead to various performance issues. In layman's terms, it's like two people trying to talk to each other but not understanding what the other is saying. This could be due to faulty wiring, corroded connectors, or even issues with the control modules themselves. If you ignore this code, you may experience symptoms like erratic dashboard lights, non-functioning accessories, or even stalling. The vehicle may enter 'limp mode' to prevent further damage, which restricts performance and limits speed. Addressing this DTC promptly is crucial to avoid more extensive repairs down the line. It's important to perform a thorough diagnostic to pinpoint the exact cause of the communication failure before proceeding with repairs.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0668 is present:
- Check engine light illuminates or flashes, indicating a fault detected in the system.
- Dashboard indicators may behave erratically, such as the fuel gauge showing empty when there is fuel.
- Power accessories like windows and mirrors may operate intermittently or fail to function.
- Engine may experience hesitation or misfires during acceleration due to communication disruptions.
- Vehicle may enter 'limp mode,' restricting speed and performance to protect the engine.
Possible Causes
Most common causes of U0668 (ordered by frequency):
- Faulty wiring or connectors (60% likelihood) - Corroded or damaged wires can disrupt signals.
- Control module failure (25% likelihood) - One of the control units may be malfunctioning.
- Grounding issues (10% likelihood) - Poor grounding can cause communication errors.
- Interference from aftermarket accessories (3% likelihood) - Non-OEM parts can interfere with signals.
- Rarely, software glitches (2% likelihood) - Outdated firmware may require an update.
U0668 Repair Costs
Cost Breakdown by Repair Type
Wiring and Connector Repair
Repair or replace damaged wiring and connectors as per the diagnostic findings.
- Total: $150 - $400
- Success rate: 85%
Control Module Replacement
Replace faulty control modules identified during diagnosis.
- Total: $500 - $1200
- Success rate: 90%
Money-Saving Tips for U0668
- 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 U0668 Diagnosis Process
Follow these systematic steps to accurately diagnose U0668. 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: Ford Focus U0668 Diagnosis and Repair
Vehicle: 2018 Ford Focus, 45,000 miles
Problem: Customer reported dashboard lights blinking and intermittent power loss.
Diagnosis: Performed visual inspection and found damaged wiring to the BCM.
Solution: Repaired wiring and cleaned connectors.
Cost: $250 (including labor and parts)
Result: Dashboard lights stabilized, and power loss issue resolved.
Case Study 2: Chevy Malibu U0668 Issue Resolved
Vehicle: 2020 Chevy Malibu, 30,000 miles
Problem: Customer experienced erratic dashboard indicators and engine hesitations.
Diagnosis: Used GeekOBD APP and found U0668 along with a faulty BCM.
Solution: Replaced the body control module.
Cost: $800 (including module and labor)
Result: Vehicle operated normally post-repair with no further issues.