U0520 - Control Module Communication Bus A Off - Common in 2015-2019 Ford F-150 and 2016-2019 Chevrolet Silverado

Quick Answer

U0520 means: U0520 indicates a communication problem between control modules in your vehicle.

Fix: Check and replace faulty components Cost: $150 - $500 Time: 90-180 minutes

Can I drive with U0520? Immediate attention is recommended to avoid further electrical issues.

Common Questions

What does U0520 mean and how does it affect my car?

The U0520 code indicates a problem with communication between your car's control modules. This can lead to various issues, including erratic performance of electronic systems, warning lights on the dashboard, and even difficulties in starting your vehicle. If this code appears, it's crucial to address it promptly to ensure your vehicle functions optimally.

What are the most common causes of U0520 and how much does it cost to fix?

Common causes of U0520 include damaged wiring, control module failures, and software glitches. Repair costs can vary widely depending on the issue but typically range from $100 for a simple software update to over $1200 for control module replacement. Diagnosing the specific cause is essential for accurate budgeting.

Can I drive my car with U0520 or should I stop immediately?

While you might be able to drive with the U0520 code, it is not advisable as it can lead to further electrical issues or safety risks. If you notice significant symptoms like steering problems or warning lights, it's best to stop driving and seek professional diagnosis.

How can I diagnose U0520 myself using GeekOBD APP?

Start by connecting the GeekOBD APP to your vehicle's OBD2 port. Use the app to scan for all trouble codes and note any related codes. Check the freeze frame data for conditions at the time the code was set, and look for any patterns or recurring issues.

What vehicles are most commonly affected by U0520?

The U0520 code is commonly reported in vehicles like the 2015-2019 Ford F-150 and the 2016-2019 Chevrolet Silverado. These models have known issues with control module communication failures, often linked to wiring problems or software errors.

How can I prevent U0520 from happening again?

To prevent U0520 from recurring, ensure regular vehicle maintenance, including checking and replacing worn wiring and connectors. Keeping your software updated and addressing any electrical issues promptly can also help maintain proper communication between control modules.

What is U0520?

The DTC U0520 trouble code indicates a communication issue between the vehicle's control modules, specifically that the control module for the communication bus A is not functioning correctly or is unable to communicate with other modules. This can result from wiring problems, software glitches, or failed modules. In simpler terms, when your car's computer systems can't talk to each other, it can cause symptoms like erratic behavior of electronic components, issues with vehicle stability, and in some cases, even prevent the vehicle from starting. For vehicle owners, this could mean facing issues such as the non-functioning infotainment system, problems with power steering, or even the check engine light illuminating on the dashboard. Ignoring this code can lead to further electrical problems, reduced vehicle functionality, and potentially more expensive repairs down the line. It's important to address U0520 promptly to ensure all systems are operating as they should, maintaining both performance and safety.

System: U - Network (Communication, CAN Bus)

Symptoms

Common symptoms when U0520 is present:

  • Check engine light stays on constantly, indicating ongoing communication failure.
  • Erratic behavior of the infotainment system, such as freezing or unexpected shutdowns, experienced by the driver.
  • Power steering issues, where steering response is slow or unresponsive, leading to potential safety risks.
  • Unexpected warning lights appearing on the dashboard that don’t correspond to actual issues.
  • Poor fuel economy, where drivers notice a significant drop in mileage, potentially due to engine control module errors.

Possible Causes

Most common causes of U0520 (ordered by frequency):

  1. The most common cause of U0520 is damaged wiring or loose connections, which account for about 60% of cases. This often occurs due to wear and tear over time.
  2. A software glitch in the control module can also trigger this code, causing it to miscommunicate with other modules. Regular software updates can help mitigate this.
  3. Faulty or failed control modules may also be a cause, especially in older vehicles or those with high mileage. Regular inspections can help catch these issues early.
  4. Less common but serious causes include water ingress into the control module connectors, which can lead to corrosion and communication failures.
  5. Rarely, issues with the vehicle’s battery or alternator can cause communication disruptions, leading to U0520 being set unintentionally.

U0520 Repair Costs

Cost Breakdown by Repair Type

Wiring Repair

Repair or replacement of damaged wiring or connectors in the communication bus system.

  • Total: $150 - $500
  • Success rate: 90%
Control Module Replacement

Replacement of a faulty control module that is unable to communicate with others.

  • Total: $400 - $1200
  • Success rate: 95%
Software Update

Updating the control module software to resolve communication issues.

  • Total: $100 - $200
  • Success rate: 80%
Money-Saving Tips for U0520
  • 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 U0520 Diagnosis Process

Follow these systematic steps to accurately diagnose U0520. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Start with an initial visual inspection of wiring and connectors related to the control modules

Step 1: Start with an initial visual inspection of wiring and connectors related to the control modules. Look for signs of wear, damage, or corrosion (5-10 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 2: Step 2: Use an OBD2 scanner or the GeekOBD APP to retrieve all codes and freeze frame data, which helps provide context for U0520 (10-15 minutes)

Step 2: Use an OBD2 scanner or the GeekOBD APP to retrieve all codes and freeze frame data, which helps provide context for U0520 (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Conduct component testing with a multimeter or specialized diagnostic tools to check the suspected faulty modules or wiring (20-30 minutes)

Step 3: Conduct component testing with a multimeter or specialized diagnostic tools to check the suspected faulty modules or wiring (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: After repairs, perform a system function test to ensure all components are communicating properly and clear any codes (10-15 minutes)

Step 4: After repairs, perform a system function test to ensure all components are communicating properly and clear any codes (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Road test the vehicle under various conditions to confirm the success of the repair and ensure no codes return (15-20 minutes)

Step 5: Road test the vehicle under various conditions to confirm the success of the repair and ensure no codes return (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

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 Wiring Repair on a 2017 Ford F-150

Vehicle: 2017 Ford F-150, 45,000 miles

Problem: Customer reported intermittent power steering and dashboard warning lights.

Diagnosis: Visual inspection revealed damaged wiring connected to the steering control module. OBD scan confirmed U0520 and related codes.

Solution: Repaired and replaced damaged wiring, cleared codes, and conducted a road test.

Cost: $300 for wiring repair.

Result: Customer reported restored power steering functionality and no reappearance of warning lights.

Case Study 2: Control Module Replacement on a 2018 Chevrolet Silverado

Vehicle: 2018 Chevrolet Silverado, 30,000 miles

Problem: Customer experienced a non-responsive infotainment system and persistent check engine light.

Diagnosis: OBD scan revealed U0520 alongside other related codes. Control module testing indicated failure.

Solution: Replaced faulty control module and updated software.

Cost: $900 for new control module and installation.

Result: Infotainment system function restored and no further issues reported after follow-up.

Diagnose U0520

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
Download GeekOBD APP Get MOBD Adapter

Code Information

Code: U0520
System: Network (Communication, CAN Bus)
Severity: HIGH
Category: Network Codes