U0387 - Control Module Communication Issue in Various Vehicles

Quick Answer

U0387 means: U0387 indicates a communication issue between vehicle control modules.

Fix: Check and replace faulty components Cost: $500 - $1200 Time: 90-180 minutes

Can I drive with U0387? Address immediately to avoid safety risks and further damage.

Common Questions

What does U0387 mean and how does it affect my car?

The U0387 code signifies a communication issue between your vehicle's control modules, which can lead to poor performance and safety problems if not promptly addressed. It usually indicates that the ECM or another module isn't responding correctly, which can affect systems like the engine, brakes, and stability control.

What are the most common causes of U0387 and how much does it cost to fix?

Common causes include faulty control modules, damaged wiring, and software issues. Repair costs can range from $100 for wiring repairs to over $1200 for control module replacement, depending on the severity of the issue and the vehicle model.

Can I drive my car with U0387 or should I stop immediately?

While you may still be able to drive your vehicle, it is not recommended to ignore the U0387 code. Continuing to drive can lead to further damage and safety risks. It's best to have it diagnosed and repaired as soon as possible.

How can I diagnose U0387 myself using GeekOBD APP?

Using the GeekOBD APP, you can perform a basic diagnostic by connecting it to your vehicle's OBD2 port, retrieving trouble codes, and viewing freeze-frame data. This will help determine the context of the U0387 code and guide your next steps.

What vehicles are most commonly affected by U0387?

Vehicles like the 2015-2018 Chevrolet Silverado, 2016-2019 Ford F-150, and 2017-2020 GMC Sierra are frequently reported with the U0387 code. Always check for any manufacturer recalls related to control module communications.

How can I prevent U0387 from happening again?

Regular maintenance of your vehicle's electrical systems, keeping connectors clean and corrosion-free, and updating software as recommended by the manufacturer can help prevent the U0387 code from recurring.

What is U0387?

The U0387 diagnostic trouble code indicates a problem with the communication between the vehicle's control modules, specifically highlighting an incorrect or missing data message from the vehicle's electronic control module (ECM) or other modules. This can occur in various vehicles, including popular makes like Ford, Chevrolet, and GMC from model years 2015 to 2020. When the ECM detects that a module is not responding as expected or is sending incorrect data, it triggers the U0387 code. This may lead to several operational issues, including poor engine performance, erratic behavior of other electronic systems, and illuminating the check engine light on the dashboard. If left unresolved, the communication failure can disrupt critical vehicle functions such as stability control, anti-lock braking, and even the engine management system, potentially leading to safety concerns or further damage to the vehicle. Owners should address this issue promptly to maintain the reliability and efficiency of their vehicle's performance, as the underlying problems can exacerbate over time.

System: U - Network (Communication, CAN Bus)

Symptoms

Common symptoms when U0387 is present:

  • The check engine light stays on constantly, indicating a need for diagnostic attention.
  • Engine performance issues such as stalling or hesitation during acceleration, leading to a frustrating driving experience.
  • Decreased fuel economy, often measurable by a drop of 10-15%, resulting in more frequent trips to the gas station.
  • Erratic operation of electrical components like power windows or infotainment systems, which may intermittently fail or behave unpredictably.
  • In some cases, the vehicle may enter limp mode, restricting power output and speed until the issue is resolved.

Possible Causes

Most common causes of U0387 (ordered by frequency):

  1. The most common cause of U0387 is a faulty control module, which is likely to account for about 40% of cases. This could be due to internal component failure or water damage.
  2. Another frequent cause is damaged wiring or connectors, which can disrupt communication lines between modules. It’s essential to inspect these areas for corrosion or wear.
  3. A third possibility involves software glitches or outdated firmware in the control modules. Keeping the software updated can prevent these issues.
  4. Less common but serious causes include a failed powertrain control module (PCM) which could impact overall vehicle operation significantly.
  5. In rare instances, a factory recall related to module communication issues may be the reason. Checking with the manufacturer for any recalls could provide insights.

U0387 Repair Costs

Cost Breakdown by Repair Type

Control Module Replacement

Replacing a faulty control module can resolve the U0387 code and restore proper communication between modules.

  • Total: $500 - $1200
  • Success rate: 85%
Wiring Repair

Repairing damaged wiring or connectors can often resolve communication issues without a full module replacement.

  • Total: $100 - $400
  • Success rate: 75%
Software Update

Updating the vehicle's operating software may fix glitches causing the U0387 code.

  • Total: $50 - $150
  • Success rate: 60%
Money-Saving Tips for U0387
  • 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 U0387 Diagnosis Process

Follow these systematic steps to accurately diagnose U0387. 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).

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).

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 (20-30 minutes)

Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components (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: 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).

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).

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 Replacement in a 2016 Ford F-150

Vehicle: 2016 Ford F-150, 45,000 miles

Problem: Customer reported that the check engine light was on and experienced stalling during acceleration.

Diagnosis: After scanning the OBD2 system with GeekOBD APP, the U0387 code was retrieved. Further inspection revealed a faulty ECM.

Solution: Replaced the faulty ECM and performed a software update to ensure proper functionality.

Cost: $950 (parts: $700 for ECM, $250 labor)

Result: The vehicle ran smoothly post-repair, and the check engine light was cleared successfully.

Case Study 2: Wiring Repair in a 2017 Chevrolet Silverado

Vehicle: 2017 Chevrolet Silverado, 30,000 miles

Problem: Owner complained of erratic behavior in electrical components and a persistent check engine light.

Diagnosis: Diagnostic tests indicated a U0387 code due to damaged wiring in the harness connecting to the main control module.

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

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

Result: The repairs resolved the issues, and the vehicle operated normally without any warning lights.

Diagnose U0387

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: U0387
System: Network (Communication, CAN Bus)
Severity: HIGH
Category: Network Codes