Quick Answer
C04AC means: DTC C04AC indicates an issue with the electric parking brake system.
Can I drive with C04AC? Immediate attention is recommended to prevent safety risks.
Common Questions
What does C04AC mean and how does it affect my car?
DTC C04AC indicates an electric parking brake issue, potentially leading to safety risks if not addressed. The vehicle may not park securely, especially on inclines, which can lead to rollaways.
What are the most common causes of C04AC and how much does it cost to fix?
Common causes include a faulty control module (costing $250-$500) and damaged wiring ($100-$200). Regular maintenance can help minimize these issues.
Can I drive my car with C04AC or should I stop immediately?
You should avoid driving the vehicle until the issue is resolved, as the parking brake may not function properly, posing a safety hazard.
How can I diagnose C04AC myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for trouble codes, view freeze frame data, and monitor real-time data to help identify the specific fault in the electric parking brake system.
What vehicles are most commonly affected by C04AC?
DTC C04AC is frequently reported in 2016-2020 Ford Explorer models, as well as other vehicles equipped with electric parking brakes.
How can I prevent C04AC from happening again?
Regular maintenance, including inspections of the parking brake components and software updates, can help prevent future occurrences of DTC C04AC.
What is C04AC?
DTC C04AC is a diagnostic trouble code that indicates a problem with the vehicle's electric parking brake system. This code is primarily found in vehicles equipped with advanced braking technology, particularly in models such as the 2016-2020 Ford Explorer. When the C04AC code is triggered, it typically means that the electric parking brake control module is experiencing an issue, which can prevent the parking brake from engaging or disengaging properly. As a result, the driver may notice that the parking brake warning light is illuminated on the dashboard. This condition can arise from a variety of factors, including wiring faults, a malfunctioning control module, or issues with the brake actuator. Ignoring this code can lead to safety concerns, such as the risk of the vehicle rolling away if parked on an incline, or further damage to the braking system. Therefore, addressing the C04AC code promptly is crucial for safe vehicle operation and maintaining the integrity of the braking system.
System: C - Chassis (ABS, Steering, Suspension)
Symptoms
Common symptoms when C04AC is present:
- Check engine light stays on constantly, indicating a persistent issue with the electric parking brake system.
- Parking brake fails to engage or disengage, making it difficult to securely park the vehicle.
- Unusual noises, such as grinding or clicking, may occur when attempting to use the parking brake.
- Dashboard warning light for the parking brake stays illuminated, signaling a fault.
- The vehicle may roll if parked on an incline, creating a significant safety hazard.
Possible Causes
Most common causes of C04AC (ordered by frequency):
- {'cause': 'Faulty electric parking brake control module', 'likelihood': '60%', 'details': 'The control module may fail due to electrical issues or software glitches.'}
- {'cause': 'Damaged wiring or connectors', 'technicalExplanation': 'Wiring that is frayed or corroded can disrupt signals between the control module and the actuator.'}
- {'cause': 'Defective parking brake actuator', 'preventionTips': 'Regular inspections can help identify wear and tear on the actuator before it fails.'}
- {'cause': 'Software malfunction', 'seriousness': "If the vehicle's software is outdated, it can lead to improper functioning of the parking brake system."}
- {'cause': 'Environmental factors', 'rarity': 'Extreme weather conditions can affect the performance of the electric components.'}
C04AC Repair Costs
Cost Breakdown by Repair Type
Replace Electric Parking Brake Control Module
Replacing the faulty control module to restore proper function.
- Total: $250 - $500
- Success rate: 85%
Repair Wiring and Connectors
Fixing damaged wiring to ensure proper communication within the system.
- Total: $100 - $200
- Success rate: 75%
Money-Saving Tips for C04AC
- 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 C04AC Diagnosis Process
Follow these systematic steps to accurately diagnose C04AC. 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 the electric parking brake control module and actuator (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the electric parking brake control module and actuator (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation of the parking brake after repairs and clear codes (10-15 minutes)
Step 4: System function test - Verify proper operation of the parking brake 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: 2018 Ford Explorer Electric Parking Brake Failure
Vehicle: 2018 Ford Explorer, 45,000 miles
Problem: Customer reported that the parking brake warning light was on and the brake would not engage.
Diagnosis: Performed a scan and found DTC C04AC. Inspected the control module and wiring.
Solution: Replaced the electric parking brake control module and repaired damaged wiring.
Cost: $400 (including parts and labor)
Result: After repairs, the parking brake functioned correctly, and the warning light was cleared.
Case Study 2: 2019 Ford Explorer Wiring Issues
Vehicle: 2019 Ford Explorer, 30,000 miles
Problem: Customer experienced intermittent failure of the electric parking brake.
Diagnosis: Ran diagnostic tests revealing C04AC, traced the issue to corroded wiring.
Solution: Repaired the damaged wiring harness and updated the software.
Cost: $150 (for wiring repair and software update)
Result: The parking brake issue was resolved, and the vehicle was safe to drive.