Quick Answer
U0084 means: U0084 indicates a communication failure between vehicle control modules.
Can I drive with U0084? Immediate attention is recommended to prevent further electrical issues.
Common Questions
What does U0084 mean and how does it affect my car?
The U0084 code indicates a communication failure between your vehicle's control modules, which can lead to various electronic malfunctions. This can affect systems like power windows, lighting, and even starting the engine. If not addressed, it could escalate into more severe electrical problems.
What are the most common causes of U0084 and how much does it cost to fix?
Common causes include damaged wiring (60% of cases), a faulty Body Control Module, or intermittent electrical connections. Repair costs range from $150 for wiring repairs to $700 for module replacements, depending on the specific issue.
Can I drive my car with U0084 or should I stop immediately?
While you might be able to drive your car, it's crucial to address U0084 as soon as possible. Ignoring it can lead to more significant electrical failures, which may compromise safety and vehicle functionality.
How can I diagnose U0084 myself using GeekOBD APP?
Using the GeekOBD APP, connect to your vehicle's OBD2 port to retrieve the U0084 code. The app provides detailed information about the fault, including freeze frame data that can help you understand the conditions under which the problem occurred.
What vehicles are most commonly affected by U0084?
U0084 is frequently reported in 2015-2018 Chevrolet Silverado models, as well as other GM vehicles from the same production years. Keep an eye out for recalls or technical service bulletins related to this code.
How can I prevent U0084 from happening again?
Regular maintenance, including checking and cleaning electrical connections, can help prevent U0084. Additionally, ensure that any modifications or repairs to your vehicle's electrical systems are performed by professionals.
What is U0084?
The diagnostic trouble code U0084 signifies a communication problem between various control modules in your vehicle, particularly the Controller Area Network (CAN). This code indicates that there is a loss of communication with the Body Control Module (BCM) or similar components. In practical terms, this means your vehicle's systems that rely on data exchange, such as power windows, lighting, and other electronic features, may not function as intended. When your vehicle's control modules can't share information, it can lead to several issues, including erratic behavior of electronic components, warning lights on the dashboard, and even failure to start. For example, if your 2017 Chevrolet Silverado throws a U0084 code, you might notice that your power locks don't respond, or your interior lights might not turn on when you open the door. It's crucial to address this issue promptly, as neglecting it could lead to further electrical problems or even safety concerns while driving. You can use an OBD2 scanner, such as the GeekOBD APP, to read the code and gather additional information to understand the fault context better. Ignoring U0084 could result in more extensive repairs down the line, so it's wise to seek a professional diagnosis and repair.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0084 is present:
- Check engine light stays on constantly, indicating an underlying issue requiring attention.
- Power windows may stop working intermittently, leading to frustration and potential safety concerns.
- Dashboard lights may flicker or fail to illuminate when expected, suggesting electrical anomalies.
- The vehicle might experience issues with starting, where it hesitates or fails to turn over.
- Interior lights may not respond when doors are opened, indicating a malfunction in the electronic control systems.
Possible Causes
Most common causes of U0084 (ordered by frequency):
- The most common cause of U0084 is damaged wiring or connectors between the control modules, accounting for about 60% of cases.
- Another significant cause is a faulty Body Control Module, which can fail to communicate with other components, leading to this code.
- Intermittent electrical connections due to corrosion or wear can also trigger U0084, highlighting the importance of regular maintenance.
- Less common but serious causes include a malfunctioning Engine Control Unit (ECU) that disrupts communication across the network.
- In rare cases, software issues or programming errors in one of the control modules can lead to a U0084 code.
U0084 Repair Costs
Cost Breakdown by Repair Type
Wiring Repair
Repair or replace damaged wiring and connectors associated with the control modules.
- Total: $150 - $400
- Success rate: 85%
Body Control Module Replacement
Replacing the faulty Body Control Module to restore communication.
- Total: $300 - $700
- Success rate: 90%
Money-Saving Tips for U0084
- 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 U0084 Diagnosis Process
Follow these systematic steps to accurately diagnose U0084. 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 check voltage and ground at connectors (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to check voltage and ground at connectors (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation of affected systems after repairs and clear codes (10-15 minutes)
Step 4: System function test - Verify proper operation of affected systems 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 Chevrolet Silverado U0084 Repair Case
Vehicle: 2017 Chevrolet Silverado 1500, 45,000 miles
Problem: Customer reported issues with power windows and dashboard lights malfunctioning.
Diagnosis: After scanning with GeekOBD, U0084 was identified. Inspected wiring harnesses for damage.
Solution: Repaired damaged wiring and replaced corroded connectors.
Cost: $250 (wiring repair and parts)
Result: All electronic systems functioned correctly post-repair, and customer reported no further issues.
Case Study 2: 2016 GMC Sierra Communication Issue
Vehicle: 2016 GMC Sierra 1500, 60,000 miles
Problem: Vehicle would intermittently fail to start and dashboard lights flickered.
Diagnosis: U0084 was found via OBD2 scan; further inspection revealed a faulty Body Control Module.
Solution: Replaced the Body Control Module and reprogrammed the vehicle’s system.
Cost: $600 (module replacement and programming)
Result: Vehicle started reliably after repair, and all systems functioned normally.