Quick Answer
U0871 means: U0871 indicates a communication issue between vehicle control modules.
Can I drive with U0871? Immediate attention is recommended to prevent unsafe driving conditions.
Common Questions
What does U0871 mean and how does it affect my car?
The U0871 code signifies a communication error between your vehicle's control modules. This can lead to various issues, such as performance problems, warning lights, and even critical safety concerns. Addressing this code promptly is essential to maintain vehicle reliability.
What are the most common causes of U0871 and how much does it cost to fix?
Common causes include faulty wiring (40% likelihood), defective control modules (30%), and poor ground connections (20%). Repair costs can range from $150 for wiring repairs to $1200 for control module replacements.
Can I drive my car with U0871 or should I stop immediately?
It's advisable to stop driving and have the issue diagnosed. Continuing to drive with this code may lead to further damage or unsafe driving conditions. Immediate attention is recommended.
How can I diagnose U0871 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for codes, view live data, and check freeze frame data. This provides context for the U0871 code and helps identify which module may be causing the communication issue.
What vehicles are most commonly affected by U0871?
The U0871 code is frequently seen in vehicles like the 2015-2018 Chevrolet Silverado, GMC Sierra, and some models of Cadillac and Buick. Always check for any known recalls or technical service bulletins (TSBs) related to your specific vehicle.
How can I prevent U0871 from happening again?
Regular maintenance, including checking wiring harnesses and connectors, can prevent future occurrences. Additionally, ensuring that software updates for your vehicle are applied can help mitigate issues.
What is U0871?
The U0871 diagnostic trouble code indicates a communication problem between the vehicle's control modules, specifically relating to the 'High Speed CAN' network. This code may arise when one or more modules fail to communicate correctly or if there is an electrical fault in the network. When this occurs, it can lead to various malfunctions, including issues with stability control, braking systems, and even engine performance. Real-world implications range from minor inconveniences, such as warning lights on the dashboard, to severe safety concerns, like loss of control in critical driving scenarios. For instance, if the body control module (BCM) fails to communicate with the engine control unit (ECU), the engine may not start or could misfire. This issue is particularly prevalent in vehicles like the Chevrolet Silverado from 2015 to 2018, where drivers may experience erratic behavior from electronic components, leaving them uncertain about the vehicle's reliability and safety. It's essential to address this code promptly to ensure that all systems are functioning harmoniously, preventing further complications down the road.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0871 is present:
- Check engine light stays on constantly, indicating a problem that requires immediate attention.
- Erratic behavior of warning lights on the dashboard, such as stability control or ABS indicators flickering or remaining on.
- Engine hesitates during acceleration, leading to decreased performance and potential safety hazards.
- Inconsistent operation of power windows or locks, which may stop functioning altogether.
- Fuel economy decreased by 10-15%, signaling possible inefficiencies due to communication failures.
Possible Causes
Most common causes of U0871 (ordered by frequency):
- Faulty wiring or connectors in the CAN bus system - 40% likelihood. Damaged wires can prevent modules from communicating effectively.
- A defective control module, such as the BCM or ECU - 30%. Modules can fail due to age or electrical issues.
- Poor ground connections affecting module performance - 20%. A weak ground can disrupt communication signals.
- Water ingress in module connectors - 5%. Moisture can lead to corrosion, causing communication failures.
- Rarely, a software glitch in the vehicle’s system - 5%. Software issues may require updates or resets to resolve.
U0871 Repair Costs
Cost Breakdown by Repair Type
Wiring Repair
Repairing damaged wiring or connectors in the CAN bus.
- Total: $150 - $400
- Success rate: 85%
Control Module Replacement
Replacing a defective control module (BCM or ECU).
- Total: $300 - $1200
- Success rate: 90%
Money-Saving Tips for U0871
- 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 U0871 Diagnosis Process
Follow these systematic steps to accurately diagnose U0871. 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 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 of U0871 in a 2017 Chevrolet Silverado
Vehicle: 2017 Chevrolet Silverado 1500, 45,000 miles
Problem: Customer reported the check engine light was on and experienced erratic behavior from the dashboard warning lights.
Diagnosis: An OBD2 scan revealed the U0871 code. Visual inspection showed frayed wiring in the CAN bus.
Solution: Repaired the damaged wiring and ensured all connections were secure.
Cost: $250 (wiring repair and diagnostic fees)
Result: After repairs, the check engine light was cleared, and all systems functioned normally.
Case Study 2: U0871 Diagnosis in a 2016 GMC Sierra
Vehicle: 2016 GMC Sierra 2500HD, 60,000 miles
Problem: The vehicle hesitated during acceleration and had a persistent check engine light.
Diagnosis: Diagnostics revealed U0871 code due to a faulty body control module.
Solution: Replaced the BCM and reprogrammed it to the vehicle.
Cost: $800 (BCM replacement and programming)
Result: Post-repair, the vehicle’s performance improved significantly, with no further issues.