U0878 - Understanding DTC U0878: Common Issues in 2015-2018 Chevrolet Silverado and Other GM Models

Quick Answer

U0878 means: DTC U0878 signifies a communication error between vehicle control modules.

Fix: Check and replace faulty components Cost: $150 - $600 Time: 90-180 minutes

Can I drive with U0878? Address this issue as soon as possible to prevent further damage.

Common Questions

What does U0878 mean and how does it affect my car?

DTC U0878 indicates a communication error between the vehicle's control modules. This could lead to performance issues like erratic shifting or warning lights. If unresolved, it may cause more severe issues affecting your vehicle's drivability and safety.

What are the most common causes of U0878 and how much does it cost to fix?

The most common cause is a damaged wiring harness, which has a high likelihood of occurring. Repair costs can range from $150 to $600. Additionally, a faulty control module may also trigger this code, costing between $400 and $1,200 to replace.

Can I drive my car with U0878 or should I stop immediately?

While it may be possible to drive your vehicle short distances with DTC U0878, it's not advisable. Ignoring it can lead to more severe problems and potential safety hazards, so addressing it promptly is crucial.

How can I diagnose U0878 myself using GeekOBD APP?

Start by connecting your GeekOBD APP to the vehicle's OBD2 port, then scan for all diagnostic trouble codes. Review any related codes and freeze frame data for context. This will help you pinpoint the issue more accurately.

What vehicles are most commonly affected by U0878?

DTC U0878 is frequently seen in 2015-2018 Chevrolet Silverado and other GM models like GMC Sierra. Owners of these vehicles should be aware of this code as it can lead to significant issues if not addressed.

How can I prevent U0878 from happening again?

Regular maintenance, including checking wiring and connectors for wear and tear, can help prevent U0878 from occurring. Also, ensuring your vehicle's software is up to date can mitigate potential software-related issues.

What is U0878?

DTC U0878 indicates a communication error between the vehicle's control modules, specifically signaling that the vehicle's control module has detected a problem with the data bus communication. In simpler terms, this code means that one or more of the vehicle's modules (like the transmission control module or the engine control module) is not receiving or sending data correctly. This issue can lead to various performance problems, such as erratic shifting, warning lights illuminating on the dashboard, or even a complete vehicle shutdown in severe cases. The communication failure may stem from problems in the wiring harness, faulty connectors, or even software glitches within the modules. For example, if your 2017 Chevrolet Silverado displays this code, you might experience rough engine performance or issues with the transmission shifting. It's crucial to address U0878 promptly because ignoring it could lead to more severe electrical problems that could affect your vehicle's drivability and safety. Additionally, if left unresolved, it could result in costly repairs down the line, particularly if other modules start to fail due to the lack of communication.

System: U - Network (Communication, CAN Bus)

Symptoms

Common symptoms when U0878 is present:

  • The 'Check Engine' light appears on the dashboard, indicating a potential problem that needs immediate attention.
  • You may notice the engine hesitating during acceleration, which could lead to a frustrating driving experience.
  • Fuel economy might decrease noticeably, potentially by 10-15%, as the vehicle struggles to communicate efficiently.
  • Unexpected stalling or shutdowns may occur while driving, posing a safety risk to both the driver and passengers.
  • In some cases, issues with the vehicle's transmission may arise, such as slipping or harsh shifts, especially in affected GM models.

Possible Causes

Most common causes of U0878 (ordered by frequency):

  1. A damaged wiring harness or loose connections account for approximately 60% of U0878 cases, causing communication failure.
  2. Another common cause is a faulty control module, which can happen due to manufacturing defects or exposure to moisture.
  3. Software issues within the vehicle's electronic control units (ECUs) may also trigger U0878; regular updates can help mitigate this.
  4. Less common, but serious, is a short circuit in the data bus wiring, which can lead to various electrical problems.
  5. Rarely, a complete failure of the vehicle’s computer system may be the underlying issue, necessitating a complete module replacement.

U0878 Repair Costs

Cost Breakdown by Repair Type

Wiring Harness Repair/Replacement

Repair or replacement of damaged wiring and connectors affecting communication.

  • Total: $150 - $600
  • Success rate: 80%
Control Module Replacement

Replacing a faulty control module that is not communicating correctly.

  • Total: $400 - $1,200
  • Success rate: 90%
Software Update

Updating the control module software to fix potential bugs causing communication errors.

  • Total: $50 - $150
  • Success rate: 70%
Money-Saving Tips for U0878
  • 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 U0878 Diagnosis Process

Follow these systematic steps to accurately diagnose U0878. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Perform an initial visual inspection to check for damaged wiring, loose connections, or signs of corrosion, which should take about 5-10 minutes

Step 1: Perform an initial visual inspection to check for damaged wiring, loose connections, or signs of corrosion, which should take about 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 with the GeekOBD APP to retrieve all diagnostic trouble codes and analyze freeze frame data to understand the context of the fault, typically taking 10-15 minutes

Step 2: Use an OBD2 scanner with the GeekOBD APP to retrieve all diagnostic trouble codes and analyze freeze frame data to understand the context of the fault, typically taking 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 using a multimeter or specific diagnostic tools to evaluate suspected components, which may take around 20-30 minutes

Step 3: Conduct component testing using a multimeter or specific diagnostic tools to evaluate suspected components, which may take around 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: Run a system function test to verify the operation of the repaired components and clear any codes, requiring about 10-15 minutes

Step 4: Run a system function test to verify the operation of the repaired components and clear any codes, requiring about 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: Complete a road test under various conditions to confirm the success of the repairs, which should take about 15-20 minutes

Step 5: Complete a road test under various conditions to confirm the success of the repairs, which should take about 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: 2017 Chevrolet Silverado U0878 Case Study

Vehicle: 2017 Chevrolet Silverado 1500, 60,000 miles

Problem: Customer reported the 'Check Engine' light and erratic shifting while driving.

Diagnosis: After scanning with GeekOBD APP, DTC U0878 was identified, prompting a visual inspection that revealed a damaged wiring harness.

Solution: Replaced the damaged wiring harness and cleared the codes. Performed a road test to confirm proper operation.

Cost: $300 (including parts and labor)

Result: Post-repair, the vehicle operated smoothly without any further issues.

Case Study 2: 2016 GMC Sierra U0878 Troubleshooting

Vehicle: 2016 GMC Sierra 1500, 75,000 miles

Problem: Customer experienced engine hesitations and dashboard warning lights.

Diagnosis: After using the GeekOBD APP to identify U0878, further testing revealed a faulty control module.

Solution: Replaced the control module and updated the software to ensure proper communication.

Cost: $950 (including control module and labor)

Result: The vehicle returned to normal functionality with no further problems reported.

Diagnose U0878

Use GeekOBD APP for professional diagnosis!

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  • Professional-grade analysis
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Code Information

Code: U0878
System: Network (Communication, CAN Bus)
Severity: HIGH
Category: Network Codes