Quick Answer
C1A39 means: C1A39 indicates a fault in the adaptive cruise control system, often related to the control module.
Can I drive with C1A39? It's recommended to address this issue immediately to ensure safe vehicle operation.
Common Questions
What does C1A39 mean and how does it affect my car?
C1A39 indicates a malfunction in the adaptive cruise control system, potentially affecting your car's ability to maintain speed. This can lead to safety issues, especially if the system fails while driving. It's important to get this diagnosed and repaired to avoid driving complications.
What are the most common causes of C1A39 and how much does it cost to fix?
The most common causes of C1A39 include a faulty cruise control module, wiring issues, and sensor malfunctions. Repair costs can range from $100 for wiring repairs to $600 for module replacement, depending on the specific issue and parts needed.
Can I drive my car with C1A39 or should I stop immediately?
While you may still be able to drive your vehicle, it's advisable to address the C1A39 code as soon as possible to prevent further complications. The cruise control system may be unreliable, posing a safety risk during highway driving.
How can I diagnose C1A39 myself using GeekOBD APP?
To diagnose C1A39 using the GeekOBD APP, connect the device to your vehicle's OBD2 port, run a scan to retrieve diagnostic codes, and review the freeze frame data to understand the context of the fault. This will help you identify potential issues before visiting a mechanic.
What vehicles are most commonly affected by C1A39?
C1A39 is frequently encountered in 2015-2018 Ford Explorers, but can also affect other Ford models with adaptive cruise control systems. Always check for any recalls or technical service bulletins related to your vehicle.
How can I prevent C1A39 from happening again?
Regular maintenance of your vehicle's electrical system, including checks on the cruise control wiring and module, can help prevent C1A39. Additionally, keeping your software updated can minimize sensor and module issues.
What is C1A39?
The Diagnostic Trouble Code (DTC) C1A39 generally indicates a problem within the vehicle's adaptive cruise control system, specifically related to the control module or its communication with other vehicle components. When this code is triggered, it often signifies that the system has detected an issue that affects its ability to maintain a steady speed or respond accurately to the driver's inputs. For vehicles like the 2015-2018 Ford Explorer, this could manifest as an inability to activate adaptive cruise control or a sudden disengagement while driving. The implications of this code can be significant, especially for those who rely on cruise control for long highway drives. Ignoring this code could lead to more severe issues down the line, such as complete failure of the cruise control system or even safety concerns while driving. Therefore, it's essential to address this issue promptly and have a professional technician diagnose and repair the underlying problem to ensure your vehicle operates safely and effectively.
System: C - Chassis (ABS, Steering, Suspension)
Symptoms
Common symptoms when C1A39 is present:
- The adaptive cruise control light on the dashboard stays illuminated, indicating a malfunction.
- Drivers may experience an inability to set or maintain a desired speed using cruise control.
- The vehicle may exhibit erratic acceleration or deceleration when the cruise control is engaged.
- In some cases, the entire cruise control system may become non-functional, leading to inconvenience during long drives.
- Error messages may appear on the dashboard notifying the driver of cruise control issues.
Possible Causes
Most common causes of C1A39 (ordered by frequency):
- A faulty adaptive cruise control module is the most common cause, with about 40% likelihood. This can occur due to wear and tear or electrical issues.
- Wiring issues, such as shorts or breaks in the wiring harness, can contribute to the problem, accounting for around 30% of cases.
- Sensor malfunctions, particularly with radar or camera sensors used in advanced cruise control systems, are another potential cause, with a 20% likelihood.
- Less common causes include software glitches within the vehicle's onboard system, which may require a software update.
- In rare instances, physical damage to the cruise control system components from accidents or extreme weather can lead to this issue.
C1A39 Repair Costs
Cost Breakdown by Repair Type
Module Replacement
Replacing the adaptive cruise control module is often necessary if it is faulty.
- Total: $300 - $600
- Success rate: 85%
Wiring Repair
Repairing damaged wires or connections may resolve the issue without module replacement.
- Total: $100 - $300
- Success rate: 70%
Sensor Replacement
Replacing faulty sensors that assist with cruise control functionality.
- Total: $200 - $400
- Success rate: 75%
Money-Saving Tips for C1A39
- 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 C1A39 Diagnosis Process
Follow these systematic steps to accurately diagnose C1A39. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Conduct an initial visual inspection of the wiring and connectors related to the adaptive cruise control system, looking for damage or corrosion (5-10 minutes)
Step 2: Use the GeekOBD APP to perform an OBD2 scan, retrieving all relevant codes and freeze frame data for further context (10-15 minutes)
Step 3: Test components such as the cruise control module and sensors using a multimeter or specialized diagnostic tools to confirm functionality (20-30 minutes)
Step 4: After repairs, perform a system function test to ensure all components are operating correctly, and clear any codes (10-15 minutes)
Step 5: Conduct a road test under various driving conditions to verify that the cruise control system functions as intended (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: Case Study: 2016 Ford Explorer with C1A39
Vehicle: 2016 Ford Explorer, 50,000 miles
Problem: Customer reported that the adaptive cruise control was not engaging.
Diagnosis: An OBD2 scan revealed the C1A39 code. Visual inspection showed damaged wiring.
Solution: Repaired the wiring harness and replaced the cruise control module.
Cost: $550
Result: Cruise control functionality restored, and the customer reported no further issues.
Case Study 2: Case Study: 2017 Ford Explorer Adaptive Cruise Control Failure
Vehicle: 2017 Ford Explorer, 30,000 miles
Problem: Adaptive cruise control light on, system not functioning.
Diagnosis: Diagnosed with a faulty radar sensor after a thorough diagnostic process.
Solution: Replaced the radar sensor and updated the vehicle software.
Cost: $400
Result: Successful repair, customer satisfied with the restored cruise control capabilities.