U0379 - Understanding the U0379 Code in Chevrolet and GMC Models

Quick Answer

U0379 means: U0379 indicates a communication error between control modules in the vehicle.

Fix: Check and replace faulty components Cost: $300 - $600 Time: 90-180 minutes

Can I drive with U0379? Should be diagnosed immediately to avoid further electrical issues.

Common Questions

What does U0379 mean and how does it affect my car?

The U0379 code signifies a communication error between the body control module and other electronic modules in your vehicle. This can lead to issues such as malfunctioning lights, erratic gauge readings, and overall poor vehicle performance. If left unaddressed, it may result in further electrical complications and affect drivability.

What are the most common causes of U0379 and how much does it cost to fix?

Common causes include a faulty body control module, damaged wiring, and software issues. Repair costs can range from $50 for a software update to $600 for a BCM replacement, depending on the severity of the issue.

Can I drive my car with U0379 or should I stop immediately?

Driving with a U0379 code can be risky, as it may lead to electrical failures while on the road. It is advisable to stop and diagnose the issue as soon as possible to prevent further damage to the vehicle's systems.

How can I diagnose U0379 myself using GeekOBD APP?

To diagnose U0379 with the GeekOBD APP, connect the device to your vehicle's OBD2 port, perform a scan to retrieve codes, and review the freeze frame data for context. This will help identify the specific module communication issue.

What vehicles are most commonly affected by U0379?

The U0379 code frequently appears in Chevrolet and GMC models, particularly from 2010 to 2018, including popular models like the Chevrolet Silverado and GMC Sierra. It’s important to check for any recalls or technical service bulletins related to these issues.

How can I prevent U0379 from happening again?

Preventing U0379 involves regular vehicle maintenance, including checking wiring and connectors for wear, ensuring software updates are performed when necessary, and being cautious with aftermarket electronics that could interfere with the vehicle’s systems.

What is U0379?

The U0379 diagnostic trouble code (DTC) signifies a communication issue within the automotive systems, particularly relating to the control modules in your vehicle. This code often appears in Chevrolet and GMC models from 2010 to 2018, where the body control module (BCM) is unable to communicate with other modules effectively. In essence, the U0379 code indicates that the control module is receiving invalid data from another module or that the data is being sent incorrectly. This could lead to various electrical issues in your vehicle, such as malfunctioning lights, erratic gauge readings, or even performance problems. It’s important to address this issue promptly, as it may affect the overall functionality of your vehicle. If left unresolved, it can lead to further complications, such as battery drainage due to the persistent communication attempts. Regular maintenance and timely diagnostics can prevent the U0379 code from becoming a recurring issue. Having a good understanding of this code helps you to be proactive about your vehicle's health, ensuring that you can make informed decisions regarding repairs and maintenance.

System: U - Network (Communication, CAN Bus)

Symptoms

Common symptoms when U0379 is present:

  • The check engine light stays on constantly, indicating a persistent issue with vehicle communication systems.
  • You may experience engine hesitation during acceleration, which can lead to a lack of power when merging onto highways.
  • Fuel economy may decrease by 10-15% as the vehicle struggles with erratic behavior from various systems.
  • Inconsistent readings from dashboard gauges, such as the speedometer or fuel gauge, leading to driver confusion.
  • Various electrical components may malfunction, such as headlights flickering or windows operating sporadically.

Possible Causes

Most common causes of U0379 (ordered by frequency):

  1. The most common cause of U0379 is a faulty body control module (BCM), which occurs in about 60% of cases. A malfunctioning BCM can disrupt communication between vehicle systems.
  2. Another potential cause is damaged wiring or connectors in the communication network. This can occur due to wear and tear or exposure to moisture, leading to a 25% likelihood of failure.
  3. Additionally, software issues or outdated firmware can cause compatibility problems, particularly in vehicles that have undergone modifications or aftermarket installations.
  4. Less commonly, a failing powertrain control module (PCM) can also trigger this code, although this is a serious issue requiring immediate attention.
  5. In rare cases, external interference from improperly installed aftermarket electronics can lead to communication errors, affecting the vehicle's operation.

U0379 Repair Costs

Cost Breakdown by Repair Type

BCM Replacement

Replacing the faulty body control module with a new OEM part.

  • Total: $300 - $600
  • Success rate: 90%
Wiring Repair

Repairing or replacing damaged wiring and connectors.

  • Total: $100 - $300
  • Success rate: 80%
Software Update

Updating the vehicle's software to ensure compatibility between modules.

  • Total: $50 - $150
  • Success rate: 75%
Money-Saving Tips for U0379
  • 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 U0379 Diagnosis Process

Follow these systematic steps to accurately diagnose U0379. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Conduct an initial visual inspection to check for damaged wiring, loose connections, or corrosion around the BCM and related connectors (5-10 minutes)

Step 1: Conduct an initial visual inspection to check for damaged wiring, loose connections, or corrosion around the BCM and related connectors (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 the GeekOBD APP to perform an OBD2 scan to retrieve all codes and freeze frame data, which will provide context for the U0379 code (10-15 minutes)

Step 2: Use the GeekOBD APP to perform an OBD2 scan to retrieve all codes and freeze frame data, which will provide context for the U0379 code (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: Test suspected components using a multimeter to check for proper voltage and resistance, particularly on the BCM and wiring harness (20-30 minutes)

Step 3: Test suspected components using a multimeter to check for proper voltage and resistance, particularly on the BCM and wiring harness (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 making repairs, conduct a system function test to verify the proper operation of all related modules and clear the codes (10-15 minutes)

Step 4: After making repairs, conduct a system function test to verify the proper operation of all related modules and clear the 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: Perform a road test to ensure that the vehicle operates correctly under various driving conditions, confirming successful repairs (15-20 minutes)

Step 5: Perform a road test to ensure that the vehicle operates correctly under various driving conditions, confirming successful repairs (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: BCM Replacement in a 2015 Chevrolet Silverado

Vehicle: 2015 Chevrolet Silverado, 75,000 miles

Problem: Customer reported multiple dashboard lights illuminating and inconsistent gauge readings.

Diagnosis: Using the GeekOBD APP, the U0379 code was identified alongside several other communication codes.

Solution: Replaced the faulty body control module with an OEM part and updated the software.

Cost: $450 (parts: $350, labor: $100)

Result: Post-repair, all symptoms resolved, and vehicle performance returned to normal.

Case Study 2: Wiring Repair in a 2012 GMC Sierra

Vehicle: 2012 GMC Sierra, 80,000 miles

Problem: Owner experienced intermittent power loss and dashboard light issues.

Diagnosis: Inspected wiring connections, leading to the discovery of corroded connectors in the BCM circuit.

Solution: Repaired the damaged wiring and replaced corroded connectors.

Cost: $200 (parts: $50, labor: $150)

Result: Vehicle functionality improved significantly, and U0379 code was cleared without recurrence.

Diagnose U0379

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: U0379
System: Network (Communication, CAN Bus)
Severity: HIGH
Category: Network Codes