U0773 - Understanding Communication Issues in 2013-2019 Chevrolet and GMC Models

Quick Answer

U0773 means: U0773 indicates a communication failure between control modules in your vehicle.

Fix: Check and replace faulty components Cost: $300 - $800 Time: 90-180 minutes

Can I drive with U0773? You should address this code as soon as possible to avoid further vehicle malfunction.

Common Questions

What does U0773 mean and how does it affect my car?

U0773 indicates a communication breakdown between your vehicle's electronic control modules. This could lead to malfunctioning features like power windows and may affect vehicle performance. It's essential to address this issue as it can worsen and lead to more severe problems.

What are the most common causes of U0773 and how much does it cost to fix?

Common causes include a faulty body control module, damaged wiring, and software-related issues. Repair costs can range from $100 for simple wiring repairs to $800 for BCM replacement, depending on the specific problem.

Can I drive my car with U0773 or should I stop immediately?

While you may be able to drive your vehicle, it is not recommended to ignore the U0773 code. The communication issues can lead to further electrical failures or safety concerns, so it's best to have it diagnosed and repaired promptly.

How can I diagnose U0773 myself using GeekOBD APP?

To diagnose U0773 using the GeekOBD APP, connect the app to your car's OBD2 port. Run a full system scan to retrieve all codes. Note any additional codes that may appear alongside U0773, as these can provide clues to the underlying issue.

What vehicles are most commonly affected by U0773?

U0773 is frequently reported in 2013-2019 Chevrolet and GMC models, including popular vehicles like the Chevrolet Silverado, GMC Sierra, and Chevy Equinox. Owners should be aware of potential recalls or Technical Service Bulletins (TSBs) that may pertain to their specific model.

How can I prevent U0773 from happening again?

Regular maintenance, including checking electrical connections and keeping the vehicle's software updated, can help prevent U0773. Additionally, be cautious with aftermarket installations, ensuring they are done correctly to avoid electrical interference.

What is U0773?

Diagnostic Trouble Code (DTC) U0773 indicates a communication issue between the vehicle's control modules, particularly in certain Chevrolet and GMC models manufactured between 2013 and 2019. This error code typically suggests that the body control module (BCM) is not receiving or sending messages to other modules, which can lead to various malfunctions. In simpler terms, it means that the electronic systems responsible for critical functions in your vehicle are unable to talk to each other effectively. This could affect features like the power locks, lights, and even the engine's performance depending on the severity. When you see this code, the check engine light will likely be illuminated, and you may experience symptoms such as erratic electrical behavior, problems with starting, and issues with vehicle accessories. Ignoring this code can lead to further complications, including battery drain or additional error codes, which may require more extensive repairs. Therefore, addressing U0773 promptly is essential to ensure the reliability and safety of your vehicle.

System: U - Network (Communication, CAN Bus)

Symptoms

Common symptoms when U0773 is present:

  • The check engine light remains illuminated continuously, indicating an underlying issue.
  • Electrical components such as power windows or door locks may malfunction or operate erratically, leading to driver frustration.
  • Engine performance issues may arise, such as difficulty starting the vehicle or random stalling, which can be alarming.
  • You may notice a decrease in fuel efficiency, as various systems are not operating optimally due to communication failures.
  • In some cases, the vehicle may enter 'limp mode', limiting power and functionality to prevent damage.

Possible Causes

Most common causes of U0773 (ordered by frequency):

  1. The most common cause of U0773 is a faulty body control module (BCM), with a likelihood of about 60%. This module is responsible for managing various electrical functions, and if it fails, communication is disrupted.
  2. A second cause could be damaged wiring or connectors, which may account for around 25% of cases. Corrosion or wear can lead to poor connections, impacting module communication.
  3. A third potential cause is software issues within the modules, which can be resolved with a simple software update from the manufacturer.
  4. Less commonly, a failing powertrain control module (PCM) can lead to this code, which may require replacement or reprogramming.
  5. In rare instances, aftermarket accessories improperly installed can interfere with vehicle communication systems, causing U0773.

U0773 Repair Costs

Cost Breakdown by Repair Type

BCM Replacement

Replacing the body control module if it is found to be faulty.

  • Total: $300 - $800
  • Success rate: 90%
Wiring Repair

Repairing damaged wiring or connectors that may be causing communication issues.

  • Total: $100 - $300
  • Success rate: 75%
Software Update

Updating the software of the control modules to resolve communication issues.

  • Total: $50 - $150
  • Success rate: 80%
Money-Saving Tips for U0773
  • 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 U0773 Diagnosis Process

Follow these systematic steps to accurately diagnose U0773. 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). Look specifically at connectors associated with the BCM and other modules.

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: 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). This will help you identify if U0773 is the only code present or if others are related.

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: Component testing - Use a multimeter or specific diagnostic tools to test suspected components like the BCM and wiring harnesses (20-30 minutes)

Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components like the BCM and wiring harnesses (20-30 minutes). Ensure that signal outputs are functioning as they should.

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: 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). Observe if any new codes appear after repairs.

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 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). Pay attention to any recurring symptoms.

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: 2016 Chevrolet Silverado BCM Replacement

Vehicle: 2016 Chevrolet Silverado 1500, 75,000 miles

Problem: Customer reported intermittent electrical issues, including power lock malfunctions and check engine light.

Diagnosis: After a thorough inspection and OBD2 scan, DTC U0773 appeared alongside other related codes, indicating a communication failure with the BCM.

Solution: Replaced the faulty BCM and reprogrammed it to ensure compatibility with the vehicle’s systems.

Cost: $650 (parts: $400 for BCM, labor: $250)

Result: All electrical systems returned to normal operation, and the check engine light was cleared with no further issues reported.

Case Study 2: 2018 GMC Sierra Wiring Repair

Vehicle: 2018 GMC Sierra 1500, 40,000 miles

Problem: Customer experienced multiple electrical issues after a recent repair, including U0773 code activation.

Diagnosis: A visual inspection revealed damaged wiring in the harness connected to the BCM, leading to communication errors.

Solution: Repaired the damaged wiring and ensured all connections were secure.

Cost: $150 (parts: $20 for connectors, labor: $130)

Result: After repair, the U0773 code was cleared, and all electrical features functioned correctly.

Diagnose U0773

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: U0773
System: Network (Communication, CAN Bus)
Severity: HIGH
Category: Network Codes