Quick Answer
U0174 means: U0174 indicates a lost communication with the Body Control Module (BCM), affecting various electrical functions.
Can I drive with U0174? Address promptly to avoid further electrical issues and ensure safety.
Common Questions
What does U0174 mean and how does it affect my car?
U0174 indicates a communication problem between the Engine Control Module and the Body Control Module. This can affect various electronic systems, leading to malfunctioning lights, locks, and warning indicators, ultimately impacting vehicle safety and performance.
What are the most common causes of U0174 and how much does it cost to fix?
Common causes include damaged wiring, a faulty BCM, and poor installation of aftermarket components. Repair costs can range from $150 for wiring repairs to $800 for BCM replacement, depending on the severity of the issue.
Can I drive my car with U0174 or should I stop immediately?
While you might be able to drive the vehicle, it's advisable to address U0174 promptly. Ignoring this code can lead to more severe electrical issues, compromising safety and performance.
How can I diagnose U0174 myself using GeekOBD APP?
Using the GeekOBD APP, scan for DTCs and review freeze-frame data to understand when the issue occurs. Check for any obvious wiring issues or defects, and consider following the app's troubleshooting guide for further insights.
What vehicles are most commonly affected by U0174?
U0174 is frequently seen in models from Ford, Chevrolet, and Dodge, especially from years 2010-2018. Owners should check for any recalls or Technical Service Bulletins (TSBs) related to electronic systems.
How can I prevent U0174 from happening again?
Regular maintenance checks, especially of the vehicle's wiring and electrical systems, can help prevent U0174. Using high-quality parts during repairs and ensuring professional installation can also minimize future issues.
What is U0174?
The U0174 diagnostic trouble code (DTC) indicates a communication error between the vehicle's Engine Control Module (ECM) and the Body Control Module (BCM). This issue often arises in various vehicle makes and models, particularly in popular brands like Ford, Chevrolet, and Dodge. When the ECM cannot receive signals from the BCM, it can lead to a range of operational problems. The BCM is responsible for numerous functions, including controlling lighting, door locks, and other electronic features. The inability to communicate effectively can result in malfunctions of these systems, leading to intermittent failures or complete inoperability of electrical components. For instance, drivers may experience issues such as malfunctioning lights, doors that won’t unlock, or even problems with the vehicle's alarm system. This code can also trigger the check engine light, prompting immediate attention. It's essential for car owners to understand that while this issue may not seem critical at first glance, ignoring it can lead to more severe electrical problems and potentially impact overall vehicle safety and performance. Addressing U0174 promptly can save time and repair costs in the long run.
System: U - Network (Communication, CAN Bus)
Symptoms
Common symptoms when U0174 is present:
- The check engine light remains illuminated, indicating a fault in the vehicle's electronic systems.
- The engine may experience hesitation or stalling during acceleration due to communication issues with the BCM.
- Drivers might notice a significant drop in fuel economy, potentially by 10-15%, as the ECM struggles to manage engine performance.
- Power windows or locks may function intermittently, causing frustration and inconvenience.
- Dashboard warning lights related to various systems may flicker or remain on, indicating broader electrical problems.
Possible Causes
Most common causes of U0174 (ordered by frequency):
- The most common cause of U0174 is damaged wiring or connectors, which accounts for about 60% of cases. Corrosion or wear can disrupt communication between modules.
- Another significant cause is a malfunctioning BCM itself, which can occur due to software glitches or internal faults, making up around 20% of reported issues.
- Poorly executed repairs or aftermarket installations can lead to communication errors, emphasizing the need for professional work.
- Less common, but serious causes include issues with the ECM, which may fail to send or receive signals, affecting multiple vehicle systems.
- A rare cause can be software incompatibility following updates or repairs, where the new software may not sync correctly with existing components.
U0174 Repair Costs
Cost Breakdown by Repair Type
Wiring Repair or Replacement
Repairing or replacing damaged wiring and connectors related to the BCM communication.
- Total: $150 - $600
- Success rate: 85%
BCM Replacement
Replacing a faulty Body Control Module with a new or refurbished unit.
- Total: $400 - $800
- Success rate: 90%
Money-Saving Tips for U0174
- 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 U0174 Diagnosis Process
Follow these systematic steps to accurately diagnose U0174. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Perform an initial visual inspection
Step 1: Perform an initial visual inspection. Look for obvious signs of damage like frayed wires or loose connectors, which can take about 5-10 minutes.
Step 2: Step 2: Use an OBD2 scanner or the GeekOBD APP to retrieve all stored codes and freeze-frame data
Step 2: Use an OBD2 scanner or the GeekOBD APP to retrieve all stored codes and freeze-frame data. This helps understand the context of the fault, requiring around 10-15 minutes.
Step 3: Step 3: Test suspected components using a multimeter or specific diagnostic tools to ensure they operate within normal parameters, which may take 20-30 minutes
Step 3: Test suspected components using a multimeter or specific diagnostic tools to ensure they operate within normal parameters, which may take 20-30 minutes.
Step 4: Step 4: After any repairs, perform a system function test to verify that all modules are communicating correctly and clear any codes, taking about 10-15 minutes
Step 4: After any repairs, perform a system function test to verify that all modules are communicating correctly and clear any codes, taking about 10-15 minutes.
Step 5: Step 5: Conduct a road test to ensure all systems operate normally under various conditions, which typically takes around 15-20 minutes
Step 5: Conduct a road test to ensure all systems operate normally under various conditions, which typically takes around 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: Repairing a 2016 Ford Fusion with U0174
Vehicle: 2016 Ford Fusion, 75,000 miles
Problem: Customer reported intermittent lighting and locking issues.
Diagnosis: Found damaged wiring harness near the BCM due to moisture intrusion.
Solution: Replaced the damaged wiring and secured the connectors.
Cost: $250 (including parts and labor)
Result: All electrical functions returned to normal, with no further issues reported.
Case Study 2: Resolving U0174 in a 2015 Chevrolet Malibu
Vehicle: 2015 Chevrolet Malibu, 60,000 miles
Problem: Customer experienced a persistent check engine light and malfunctioning central locking system.
Diagnosis: Diagnosed a faulty BCM that failed to communicate with the ECM.
Solution: Replaced the BCM with a new unit and reprogrammed it.
Cost: $650 (parts and labor included)
Result: The vehicle's systems operated correctly post-repair, with no further codes logged.