Quick Answer
B104C means: B104C indicates a malfunction with the driver's door lock control circuit.
Can I drive with B104C? Address promptly to avoid potential security risks.
Common Questions
What does B104C mean and how does it affect my car?
The B104C code signifies an issue with the Body Control Module related to the driver's door lock. This can lead to your door not locking or unlocking properly, potentially compromising your vehicle's security and functionality.
What are the most common causes of B104C and how much does it cost to fix?
Common causes include a faulty door lock actuator (40% chance) and wiring issues. Repair costs can range from $100 for wiring repairs to $600 if the BCM needs replacement.
Can I drive my car with B104C or should I stop immediately?
While you can drive with this code, it's advisable to address it promptly as it may affect your door locking mechanisms, posing a security risk.
How can I diagnose B104C myself using GeekOBD APP?
Start by connecting your GeekOBD APP to read diagnostic codes. Check for B104C and inspect the associated door lock actuator and wiring for any obvious issues.
What vehicles are most commonly affected by B104C?
Commonly found in models like the 2015-2018 Honda Civic, Ford Focus, and Chevrolet Malibu, especially those with electronic locking systems.
How can I prevent B104C from happening again?
Regular maintenance checks on your vehicle's electrical system, keeping connectors clean, and ensuring the BCM software is up-to-date can help prevent this code from reoccurring.
What is B104C?
The Diagnostic Trouble Code (DTC) B104C indicates a problem with the vehicle's Body Control Module (BCM) specifically related to the driver's door lock. This code is often triggered when the BCM detects an inconsistency in the communication with the door lock actuator or if there’s an issue with the wiring harness connected to it. For owners of vehicles like the 2015-2018 Honda Civic, encountering this code can lead to various problems, such as the inability to lock or unlock the driver’s door using the key fob or the vehicle's interior switch. This can be frustrating and may pose security risks if not addressed promptly. The BCM plays a crucial role in managing multiple electronic functions in the vehicle, and a fault in this module can lead to cascading issues, affecting other systems as well. Ignoring the B104C code can lead to further electrical problems, potentially resulting in higher repair costs down the line. Therefore, it's essential to diagnose and repair any issues associated with this code as soon as possible to ensure your vehicle remains safe and functional.
System: B - Body (Airbags, Lighting, Security, Climate Control)
Symptoms
Common symptoms when B104C is present:
- The check engine light remains illuminated, indicating a persistent issue with the BCM.
- The driver's door lock does not respond to the key fob or interior switch, leaving the door unlocked.
- There is a noticeable delay or failure when trying to lock or unlock the vehicle, particularly with the driver's side.
- Intermittent electrical issues may arise, such as flickering interior lights when opening the driver's door.
- The central locking system may fail to engage, preventing all doors from locking/unlocking simultaneously.
Possible Causes
Most common causes of B104C (ordered by frequency):
- {'cause': 'Faulty door lock actuator', 'likelihood': '40%', 'details': 'The door lock actuator can wear out over time, especially if frequently used, leading to failure in locking mechanisms.'}
- {'cause': 'Wiring issues or corrosion', 'details': 'Damaged wiring or corrosion in the connectors can disrupt communication between the BCM and the door lock actuator, causing the B104C code to trigger.'}
- {'cause': 'BCM software glitch', 'details': 'Sometimes, a software update or glitch in the BCM can cause communication errors. Keeping the BCM updated can prevent this issue.'}
- {'cause': 'Malfunctioning BCM', 'details': 'A complete failure of the BCM itself, though rare, can lead to the B104C code and may require replacement.'}
- {'cause': 'Environmental factors', 'details': "Moisture or debris entering the door's electrical components can lead to short circuits, triggering the B104C code."}
B104C Repair Costs
Cost Breakdown by Repair Type
Door Lock Actuator Replacement
Replacing the faulty door lock actuator to restore proper locking function.
- Total: $150 - $300
- Success rate: 85%
Wiring Repair or Replacement
Repairing or replacing damaged wiring connections leading to the actuator.
- Total: $100 - $200
- Success rate: 90%
BCM Replacement
Replacing a malfunctioning Body Control Module.
- Total: $300 - $600
- Success rate: 95%
Money-Saving Tips for B104C
- 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 B104C Diagnosis Process
Follow these systematic steps to accurately diagnose B104C. 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 to measure voltage and resistance at the door lock actuator (20-30 minutes)
Step 3: Component testing - Use a multimeter to measure voltage and resistance at the door lock actuator (20-30 minutes).
Step 4: Step 4: Check wiring - Inspect wiring harnesses for wear or damage and ensure connections are secure (15-20 minutes)
Step 4: Check wiring - Inspect wiring harnesses for wear or damage and ensure connections are secure (15-20 minutes).
Step 5: Step 5: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)
Step 5: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes).
Step 6: Step 6: Road test verification - Drive the vehicle under various conditions to confirm that the issue is resolved (15-20 minutes)
Step 6: Road test verification - Drive the vehicle under various conditions to confirm that the issue is resolved (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: Door Lock Actuator Replacement on 2016 Honda Civic
Vehicle: 2016 Honda Civic, 45,000 miles
Problem: Customer reported that the driver's door lock was unresponsive to both the key fob and interior switch.
Diagnosis: After scanning the vehicle with the GeekOBD APP, B104C was confirmed. A visual inspection revealed a faulty door lock actuator.
Solution: Replaced the door lock actuator, and the locking mechanism functioned correctly thereafter.
Cost: $250 (includes parts and labor)
Result: Customer reported satisfaction with the repairs and confirmed that the door lock operated smoothly.
Case Study 2: Wiring Repair on 2017 Ford Focus
Vehicle: 2017 Ford Focus, 30,000 miles
Problem: Intermittent issues with the driver's door lock not responding.
Diagnosis: GeekOBD APP showed B104C; further inspection revealed damaged wiring harness leading to the actuator.
Solution: Repaired the damaged wiring and secured connections.
Cost: $150 (including labor)
Result: The locking system worked flawlessly after the repair, and the customer was pleased with the quick turnaround.