Quick Answer
U0935 means: DTC U0935 indicates a communication error between vehicle control modules.
Can I drive with U0935? Immediate attention is recommended to prevent further electrical issues.
Common Questions
What does U0935 mean and how does it affect my car?
U0935 indicates a communication error between the vehicle's control modules, which can lead to various electrical issues and performance problems. If your car's modules can't talk to each other, you might experience warning lights, failure of electronic features, or even erratic vehicle behavior.
What are the most common causes of U0935 and how much does it cost to fix?
Common causes of U0935 include a faulty body control module, damaged wiring, or loose connections. Repair costs can vary significantly; BCM replacement can cost between $300 and $800, while wiring repairs might range from $150 to $400.
Can I drive my car with U0935 or should I stop immediately?
It's advisable to stop driving if you receive a U0935 code. Continuing to drive may lead to more severe electrical issues and could affect safety features in your vehicle.
How can I diagnose U0935 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan your vehicle for trouble codes and view freeze frame data to understand the conditions when the code was triggered. This can help pinpoint the issue and guide your repairs.
What vehicles are most commonly affected by U0935?
U0935 is frequently found in Chevrolet Silverado and GMC Sierra models from 2010 to 2018, as well as some Cadillac and Buick models. Always check for any recalls or technical service bulletins related to the body control module in these vehicles.
How can I prevent U0935 from happening again?
Regular maintenance is key. Inspect wiring and connectors for damage during routine checks, and keep your vehicle's electrical system clean and dry to prevent moisture-related issues.
What is U0935?
DTC U0935 is a diagnostic trouble code indicating a communication error between the vehicle's control modules, specifically related to the body control module (BCM) or another module within the network. This code is often seen in various Chevrolet and GMC models, particularly those manufactured from 2010 to 2018. When U0935 is triggered, it means that one or more of the modules in the vehicle's network are not communicating properly, which can lead to several issues, including malfunctioning electrical components, erratic behavior of the vehicle’s systems, or even a complete loss of functionality in certain modules. Car owners may notice symptoms such as intermittent failures of electronic components, dashboard warning lights, or even performance issues. If left unchecked, these communication problems can escalate, potentially leading to more significant electrical failures or safety risks while driving. It's crucial to address this code promptly, especially in vehicles equipped with advanced safety features that rely on proper module communication to function correctly.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0935 is present:
- Check engine light stays on constantly, indicating a fault in the vehicle's communication network.
- Dashboard warning lights may flash intermittently, signaling potential issues with vehicle systems.
- Electronic components such as power windows or locks may malfunction or work sporadically.
- Performance issues may arise, including erratic engine performance or problems with stability control systems.
- In some cases, the vehicle may enter 'limp mode', reducing power to protect the engine and transmission.
Possible Causes
Most common causes of U0935 (ordered by frequency):
- The most common cause of U0935 is a faulty body control module (BCM), with an estimated likelihood of 40%. This can occur due to internal failures or exposure to moisture.
- A second common cause is damaged or corroded wiring in the communication network, which can disrupt the signals between modules, accounting for about 30% of cases.
- Improperly seated or damaged connectors can also trigger this code, and regular inspections of electrical connections can prevent this issue.
- Less common but serious causes include software glitches in the control modules, which may require reprogramming to resolve.
- A rare cause could be a complete failure of the vehicle's main wiring harness, which is costly and labor-intensive to repair.
U0935 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: 85%
Wiring Repair
Repairing or replacing damaged wiring in the network.
- Total: $150 - $400
- Success rate: 75%
Software Update
Reprogramming the BCM or other control modules to fix communication issues.
- Total: $100 - $200
- Success rate: 70%
Money-Saving Tips for U0935
- 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 U0935 Diagnosis Process
Follow these systematic steps to accurately diagnose U0935. 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).
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).
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components, focusing on the BCM and associated wiring (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components, focusing on the BCM and associated wiring (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes to see if the problem reoccurs (10-15 minutes)
Step 4: System function test - Verify proper operation after repairs and clear codes to see if the problem reoccurs (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success, ensuring all systems function correctly (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success, ensuring all systems function correctly (15-20 minutes).
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: Chevrolet Silverado BCM Replacement
Vehicle: 2015 Chevrolet Silverado 1500, 60,000 miles
Problem: Customer reported intermittent failures of power windows and dashboard warning lights.
Diagnosis: Performed a full diagnostic scan and identified U0935. Visual inspection revealed corrosion on the BCM connector.
Solution: Replaced the body control module and cleaned all connectors to ensure proper communication.
Cost: $600 (Parts: $400 for BCM, $200 labor)
Result: Post-repair, all electronic functions were restored, and the customer reported no further issues.
Case Study 2: GMC Terrain Wiring Repair
Vehicle: 2017 GMC Terrain, 40,000 miles
Problem: Customer experienced a check engine light and erratic dashboard readings.
Diagnosis: Scanned for DTCs and confirmed U0935. Found damaged wiring in the communication harness.
Solution: Repaired the damaged wiring and secured all connections.
Cost: $250 (Parts: $50 for wiring, $200 labor)
Result: After repair, no warning lights returned, and the vehicle functioned normally.