U0066 - Understanding DTC U0066: Common Issues in 2015-2018 Ford F-150 and Chevrolet Silverado

Quick Answer

U0066 means: DTC U0066 signifies a communication problem between control modules in your vehicle's CAN bus system.

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

Can I drive with U0066? Address this issue as soon as possible to avoid further complications.

Common Questions

What does U0066 mean and how does it affect my car?

DTC U0066 indicates a communication problem between the control modules in your vehicle, which can lead to various performance issues. If this code appears, it can affect how your engine runs, the efficiency of your fuel use, and even critical safety systems like brakes and traction control.

What are the most common causes of U0066 and how much does it cost to fix?

Common causes of U0066 include damaged wiring (50% of cases) and faulty control modules. Repair costs can range from $150 for wiring repairs to $1,200 for module replacements, depending on the vehicle and severity of the issue.

Can I drive my car with U0066 or should I stop immediately?

While you might be able to drive your vehicle with this code, it is not advisable. Ignoring U0066 can lead to further issues and compromise vehicle safety. It’s best to have it diagnosed and repaired as soon as possible.

How can I diagnose U0066 myself using GeekOBD APP?

To diagnose U0066 using the GeekOBD APP, connect the app to your vehicle’s OBD2 port. Scan for codes, review freeze frame data for context, and check for any other related codes that could help pinpoint the problem.

What vehicles are most commonly affected by U0066?

DTC U0066 is commonly seen in vehicles like the 2015-2018 Ford F-150 and Chevrolet Silverado. Always check for recalls or technical service bulletins (TSBs) that may relate to communication issues in these models.

How can I prevent U0066 from happening again?

To prevent U0066 from recurring, ensure regular maintenance checks on wiring and connectors, avoid low-quality aftermarket installations, and keep the vehicle's software updated through the manufacturer.

What is U0066?

DTC U0066 indicates a communication issue between control modules in your vehicle, specifically related to the CAN (Controller Area Network) bus system. This code is often triggered when there is a fault in the communication line, which can result from damaged wiring, a failed module, or even interference from aftermarket devices. It can lead to serious performance issues, affecting the vehicle's ability to function properly. For instance, if your Ford F-150 or Chevrolet Silverado is experiencing this code, you may notice erratic behavior in various systems, such as the engine management or transmission. This can manifest as poor engine performance, erratic shifts, or even safety issues like anti-lock brake failure. Ignoring this code could lead to further complications, making the vehicle less reliable and potentially unsafe for driving. Therefore, understanding U0066 and addressing it promptly is essential to ensure your vehicle operates smoothly and reliably.

System: U - Network (Communication, CAN Bus)

Symptoms

Common symptoms when U0066 is present:

  • Check engine light stays on constantly, indicating a persistent issue in the vehicle's communication system.
  • Engine hesitates during acceleration, which may affect overall performance and responsiveness.
  • Fuel economy decreased by 10-15%, leading to increased operational costs and more frequent visits to the gas station.
  • Unresponsive or malfunctioning dashboard lights, making it difficult to monitor vehicle systems.
  • Erratic transmission shifts, which can lead to a rough driving experience and potential safety vulnerabilities.

Possible Causes

Most common causes of U0066 (ordered by frequency):

  1. The most common cause of U0066 is damaged wiring or connectors, which accounts for approximately 50% of cases. This can occur from wear and tear or environmental factors.
  2. A second common cause is a faulty control module, where the module responsible for communication fails, leading to a lack of data transmission between systems.
  3. Thirdly, interference from aftermarket devices, like non-OEM radios or alarms, can disrupt the CAN bus communication, resulting in this code. Always ensure aftermarket installations are high-quality and properly integrated.
  4. Less commonly, a software glitch in the vehicle's modules can trigger U0066, which might require a software update from the manufacturer.
  5. Rarely, complete failure of the CAN bus network may occur, necessitating extensive repairs or replacements of multiple systems.

U0066 Repair Costs

Cost Breakdown by Repair Type

Wiring Repair

Repairing or replacing damaged wiring and connectors that may be causing U0066.

  • Total: $150 - $500
  • Success rate: 85%
Control Module Replacement

Replacing a faulty control module that is not communicating properly.

  • Total: $300 - $1,200
  • Success rate: 90%
Software Update

Performing a software update to rectify communication errors within the control modules.

  • Total: $100 - $200
  • Success rate: 70%
Money-Saving Tips for U0066
  • 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 U0066 Diagnosis Process

Follow these systematic steps to accurately diagnose U0066. 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). Ensure you have a good flashlight to identify hidden issues.

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 - Use the app to retrieve all codes and freeze frame data to understand the context of the fault (10-15 minutes)

Step 2: OBD2 scan with GeekOBD APP - Use the app to retrieve all codes and freeze frame data to understand the context of the fault (10-15 minutes). This step is crucial for pinpointing the problem.

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 - Utilize a multimeter or specific diagnostic tools to test suspected components, ensuring they operate within specified parameters (20-30 minutes)

Step 3: Component testing - Utilize a multimeter or specific diagnostic tools to test suspected components, ensuring they operate within specified parameters (20-30 minutes). Pay attention to voltage readings.

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 - After repairs, verify proper operation of the systems involved and clear the codes (10-15 minutes)

Step 4: System function test - After repairs, verify proper operation of the systems involved and clear the codes (10-15 minutes). This is important to confirm the issue has been resolved.

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 and ensure normal operation (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure normal operation (15-20 minutes). This helps to ensure no new codes are triggered.

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: Wiring Repair on 2016 Ford F-150

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

Problem: Owner reported check engine light on and poor engine performance.

Diagnosis: Initial scan revealed U0066. A visual inspection showed frayed wiring in the CAN bus system.

Solution: Repaired the damaged wiring and secured connectors. Cleared codes and performed a function test.

Cost: $250 (Parts: $50 for connectors, labor: $200)

Result: Check engine light went off, and the vehicle performed normally during road tests.

Case Study 2: Control Module Replacement on 2017 Chevrolet Silverado

Vehicle: 2017 Chevrolet Silverado, 60,000 miles

Problem: Customer experienced erratic shifts and dashboard warning lights.

Diagnosis: OBD scan confirmed U0066. Further tests indicated a faulty transmission control module.

Solution: Replaced the transmission control module and updated software.

Cost: $800 (Parts: $600 for module, labor: $200)

Result: After repairs, the truck's performance returned to normal, and no further codes were detected.

Diagnose U0066

Use GeekOBD APP for professional diagnosis!

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  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: U0066
System: Network (Communication, CAN Bus)
Severity: HIGH
Category: Network Codes