Quick Answer
U0955 means: DTC U0955 indicates a communication error between vehicle control modules.
Can I drive with U0955? Immediate action is recommended to prevent further issues.
Common Questions
What does U0955 mean and how does it affect my car?
DTC U0955 indicates a failure in communication between your car's control modules, which can lead to various performance issues, including erratic transmission behavior and reduced engine performance.
What are the most common causes of U0955 and how much does it cost to fix?
Common causes include loose wiring connections, faulty control modules, and software issues, with repair costs ranging from $150 for wiring repairs to over $1,200 for control module replacements.
Can I drive my car with U0955 or should I stop immediately?
While you might be able to drive your vehicle, it's not advisable to ignore U0955, as it can lead to significant performance issues and possible safety hazards. It's best to have it diagnosed as soon as possible.
How can I diagnose U0955 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for DTCs and view freeze frame data to understand when the issue occurs, helping you identify potential causes.
What vehicles are most commonly affected by U0955?
DTC U0955 is commonly found in 2015-2020 Ford F-150 and 2016-2019 Chevy Silverado models, but it can occur in other vehicles with similar communication networks.
How can I prevent U0955 from happening again?
Regularly inspect wiring and connectors, keep software updated, and perform scheduled maintenance to help prevent issues related to the U0955 code.
What is U0955?
DTC U0955 refers to a communication error between the vehicle's modules, indicating that the control module is unable to communicate with the required system. This code is particularly common in vehicles like the 2015-2020 Ford F-150 and the 2016-2019 Chevy Silverado. When this code appears, it typically signifies a failure in the data communication network of the vehicle, which can affect various systems, including engine performance, transmission control, and overall vehicle diagnostics. The root cause of this code can range from a disconnected wiring harness to a faulty control module. Ignoring U0955 can lead to more serious issues, such as degraded performance or complete system failures, affecting your vehicle's safety and reliability. It's crucial to address this code promptly to ensure that all systems are functioning correctly and to prevent further damage. If left unresolved, it can lead to increased repair costs and potential safety hazards.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0955 is present:
- Check engine light stays on constantly, indicating a persistent communication issue.
- Transmission may shift erratically or may not shift at all, causing a poor driving experience.
- Engine performance can be noticeably affected, with symptoms like stalling or reduced power during acceleration.
- Various warning lights may illuminate on the dashboard, including ABS and traction control warnings.
- Increased fuel consumption, potentially due to improper engine management caused by communication failure.
Possible Causes
Most common causes of U0955 (ordered by frequency):
- Loose or damaged wiring connections (60% likelihood) - Often, the issue is simply a loose connector that has come undone or corroded over time.
- Faulty control module (25% likelihood) - If the control module itself is malfunctioning, it may fail to communicate properly with other systems.
- Software issues (10% likelihood) - Outdated software or glitches in the system can cause communication failures.
- Grounding issues (4% likelihood) - Poor ground connections can disrupt the electrical signals necessary for module communication.
- Rarely, physical damage to the wiring harness due to road debris or wear can lead to this code.
U0955 Repair Costs
Cost Breakdown by Repair Type
Wiring Harness Repair
Repair or replacement of damaged wiring harness connections.
- Total: $150 - $300
- Success rate: 80%
Control Module Replacement
Replacing a faulty control module if it's determined to be the issue.
- Total: $500 - $1,200
- Success rate: 90%
Money-Saving Tips for U0955
- 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 U0955 Diagnosis Process
Follow these systematic steps to accurately diagnose U0955. 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 (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components (20-30 minutes).
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).
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).
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: Repair of U0955 in a 2017 Ford F-150
Vehicle: 2017 Ford F-150, 45,000 miles
Problem: Customer reported check engine light and transmission issues.
Diagnosis: After running a diagnostic scan, U0955 was identified alongside other codes related to transmission control.
Solution: A loose connector in the wiring harness was repaired, and the control module was updated with the latest software.
Cost: $250 (diagnostics and repairs)
Result: The check engine light was cleared, and the transmission function returned to normal.
Case Study 2: Resolving U0955 in a 2018 Chevy Silverado
Vehicle: 2018 Chevy Silverado, 30,000 miles
Problem: Customer experienced erratic shifting and engine performance issues.
Diagnosis: OBD2 scan revealed U0955 and confirmed a faulty control module was the culprit.
Solution: Replaced the control module and verified all connections were secure.
Cost: $900 (including parts and labor)
Result: Post-repair, the vehicle operated smoothly with no further issues.