Quick Answer
U086A means: U086A indicates a communication error in the vehicle's network due to a malfunctioning control module.
Can I drive with U086A? Immediate attention is recommended to prevent further damage and ensure safety.
Common Questions
What does U086A mean and how does it affect my car?
The U086A code signifies a communication failure within the vehicle's network. It can disrupt various systems, leading to performance issues like erratic shifting or reduced fuel efficiency. If ignored, it may escalate into more severe problems, impacting safety and drivability.
What are the most common causes of U086A and how much does it cost to fix?
Common causes include faulty control modules, damaged wiring, and software glitches. Repair costs can vary widely, with control module replacements averaging between $300 and $1,200, while wiring repairs may range from $100 to $500.
Can I drive my car with U086A or should I stop immediately?
While you may be able to drive with U086A, it's advisable to stop and diagnose the issue as soon as possible. Driving with this code can lead to safety concerns, including loss of power or erratic vehicle behavior.
How can I diagnose U086A myself using GeekOBD APP?
To diagnose U086A with GeekOBD APP, connect the device to your OBD2 port, scan for trouble codes, and review freeze frame data. Look for any other related codes that may provide additional context to the U086A fault.
What vehicles are most commonly affected by U086A?
Vehicles from Chevrolet, GMC, and Cadillac manufactured between 2014 and 2020 are frequently affected by the U086A code. Specific models include the Chevrolet Silverado and GMC Sierra.
How can I prevent U086A from happening again?
To prevent U086A, ensure regular maintenance of electrical systems, check for corrosion during routine inspections, and keep software updated. Integrating proper care can significantly reduce the likelihood of communication errors.
What is U086A?
The diagnostic trouble code (DTC) U086A indicates a communication error in the vehicle's network, specifically pointing towards a failure in the Controller Area Network (CAN) communication. This code typically arises when the engine control module (ECM) detects that a module within the vehicle's network, such as the transmission control module (TCM) or any other electronic control unit (ECU), is not responding correctly. This can lead to various performance issues, as the modules rely on seamless communication for optimal vehicle operation. For instance, if the ECM cannot receive necessary data from the TCM due to a communication error, it may affect shifting performance, fuel efficiency, and overall drivability. Owners of affected vehicles might notice symptoms like warning lights on the dashboard, reduced power, or erratic shifting. Ignoring this code can lead to more significant issues, potentially affecting vehicle safety and performance. Therefore, addressing U086A promptly is crucial for maintaining the health of your vehicle.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U086A is present:
- The check engine light remains illuminated, indicating a communication fault that needs addressing.
- Drivers may experience erratic engine performance, such as stalling or hesitation during acceleration, which can be alarming.
- Fuel economy may decrease significantly, sometimes by 10-20%, as the vehicle operates inefficiently without proper communication.
- Transmission may exhibit rough shifting or delays in engagement, making driving uncomfortable and potentially unsafe.
- In some cases, the vehicle may enter 'limp mode,' restricting power to protect the engine from damage.
Possible Causes
Most common causes of U086A (ordered by frequency):
- The most common cause of U086A is a malfunctioning control module or poor connections, occurring in about 60% of cases, often due to corrosion or physical damage.
- Another potential cause could be damaged wiring or connectors within the CAN bus system, leading to intermittent communication failures.
- Software glitches in the vehicle's control modules can also trigger this code; regular updates or resets may prevent this issue.
- Less common but serious causes include a failing battery or alternator, which can affect the power supply to the modules and disrupt communication.
- Although rare, water intrusion into electronic control units can result in U086A, especially in vehicles that have experienced flooding or poor sealing.
U086A Repair Costs
Cost Breakdown by Repair Type
Control Module Replacement
Replacing a faulty control module that is unable to communicate effectively.
- Total: $300 - $1,200
- Success rate: 85%
Wiring Repair
Repairing or replacing damaged wiring or connectors in the CAN bus system.
- Total: $100 - $500
- Success rate: 75%
Software Update
Performing a software update to rectify communication issues due to glitches.
- Total: $50 - $150
- Success rate: 60%
Money-Saving Tips for U086A
- 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 U086A Diagnosis Process
Follow these systematic steps to accurately diagnose U086A. 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 and wiring integrity (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components and wiring integrity (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)
Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure the code does not return (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure the code does not return (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: Control Module Replacement in 2017 Chevrolet Silverado
Vehicle: 2017 Chevrolet Silverado 1500, 75,000 miles
Problem: Customer reported check engine light and erratic transmission shifts.
Diagnosis: Upon scanning with GeekOBD APP, U086A was the primary code. Further inspection revealed a faulty TCM.
Solution: Replaced the transmission control module and recalibrated the system.
Cost: $800 (Parts: $600, Labor: $200)
Result: After the repair, the vehicle performed well with no return of the code.
Case Study 2: Wiring Repair on 2016 GMC Terrain
Vehicle: 2016 GMC Terrain, 60,000 miles
Problem: Customer experienced stalling and check engine light activation.
Diagnosis: GeekOBD APP revealed U086A along with a secondary code for wiring issues.
Solution: Repaired damaged wiring in the CAN bus system.
Cost: $250 (Parts: $100, Labor: $150)
Result: The vehicle’s performance improved significantly, and the codes cleared successfully.