Quick Answer
C0139 means: C0139 indicates a malfunction with the left rear ABS sensor.
Can I drive with C0139? Address immediately to maintain safe braking performance.
Common Questions
What does C0139 mean and how does it affect my car?
C0139 indicates a problem with the left rear ABS sensor, which is crucial for maintaining safe braking. If this sensor fails, your vehicle's braking performance can be compromised, leading to longer stopping distances and increased risk of accidents.
What are the most common causes of C0139 and how much does it cost to fix?
The most common cause is a faulty wheel speed sensor, accounting for about 70% of cases, with repair costs ranging from $150 to $300. Other causes include wiring issues and faulty ABS control modules, which may increase repair expenses.
Can I drive my car with C0139 or should I stop immediately?
It’s not advisable to drive your vehicle with the C0139 code. The ABS system's effectiveness is compromised, which can lead to dangerous situations if you need to brake suddenly. It's best to have your vehicle inspected as soon as possible.
How can I diagnose C0139 myself using GeekOBD APP?
Using the GeekOBD APP, perform an OBD2 scan to retrieve the C0139 code. Analyze the freeze frame data for more context on the issue. You can also check the wheel speed sensor's resistance and inspect the wiring visually for any damage.
What vehicles are most commonly affected by C0139?
Commonly affected vehicles include 2010-2015 Toyota Camry, 2013-2017 Honda Accord, and other models from manufacturers like Ford and Nissan that utilize similar ABS systems. Checking for recalls or technical service bulletins (TSBs) specific to your vehicle can also provide insights.
How can I prevent C0139 from happening again?
Regular maintenance of your vehicle, including checking the ABS system during routine inspections, can help prevent C0139. Keeping the wheel wells clean and free of debris can also protect the sensors from damage.
What is C0139?
The diagnostic trouble code (DTC) C0139 indicates a malfunction within the Anti-lock Brake System (ABS) sensor circuit, specifically related to the left rear wheel speed sensor. This code is commonly found in various makes and models, including the 2010-2015 Toyota Camry, 2013-2017 Honda Accord, and several other vehicles. The ABS plays a crucial role in maintaining vehicle stability and control during braking, particularly in slippery conditions. When the ABS sensor fails, drivers may experience issues such as the ABS warning light illuminating on the dashboard, compromised braking performance, and even the potential for the wheels to lock up in emergency braking situations. Ignoring this code can lead to serious safety risks, as the ABS system is essential for preventing wheel lockup during sudden stops. In practical terms, if you notice the ABS light on your dashboard, it’s vital to address the issue as soon as possible to ensure your braking system remains effective and safe. Understanding C0139 is key for proactive vehicle maintenance and safety.
System: C - Chassis (ABS, Steering, Suspension)
Symptoms
Common symptoms when C0139 is present:
- ABS warning light activates on your dashboard, typically during start-up or while driving.
- Vehicle experiences longer stopping distances, particularly noticeable in wet or slippery conditions.
- Unusual noises such as grinding or clicking may occur when braking, indicating potential sensor issues.
- Fluctuations in brake pedal feel, with the pedal feeling spongy or excessively hard during braking.
- Inconsistent brake performance, where the ABS engages unexpectedly during normal braking situations.
Possible Causes
Most common causes of C0139 (ordered by frequency):
- Faulty left rear wheel speed sensor - This is the most common cause, with about 70% likelihood. Sensors can fail due to wear or damage from road conditions.
- Wiring issues or bad connections - Damaged or corroded wiring can disrupt the signal sent to the ABS module, causing the C0139 code.
- Faulty ABS control module - Though less common, a malfunction in the ABS module can lead to incorrect readings from the wheel speed sensors.
- Sensor misalignment - If the sensor is misaligned or improperly installed, it may not function correctly, leading to C0139.
- Contaminated sensor - Dirt or debris on the sensor can impair its function, resulting in erroneous readings.
C0139 Repair Costs
Cost Breakdown by Repair Type
Left Rear Wheel Speed Sensor Replacement
Replacing the faulty sensor with a new OEM part to restore ABS functionality.
- Total: $150 - $300
- Success rate: 90%
Wiring Repair or Replacement
Repairing or replacing damaged wiring and connectors in the ABS circuit.
- Total: $100 - $250
- Success rate: 80%
Money-Saving Tips for C0139
- 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 C0139 Diagnosis Process
Follow these systematic steps to accurately diagnose C0139. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Look for signs of damaged wiring, loose connections, or corrosion in the ABS sensor circuit (5-10 minutes)
Step 1: Initial visual inspection - Look for signs of damaged wiring, loose connections, or corrosion in the ABS sensor circuit (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Use the app to retrieve all trouble codes and freeze frame data, which helps in understanding the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Use the app to retrieve all trouble codes and freeze frame data, which helps in understanding the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Test the left rear wheel speed sensor's resistance with a multimeter to see if it falls within the manufacturer's specifications (20-30 minutes)
Step 3: Component testing - Test the left rear wheel speed sensor's resistance with a multimeter to see if it falls within the manufacturer's specifications (20-30 minutes).
Step 4: Step 4: System function test - After repairs, test the brake system to ensure proper operation and clear any diagnostic codes (10-15 minutes)
Step 4: System function test - After repairs, test the brake system to ensure proper operation and clear any diagnostic codes (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm that the ABS system is functioning correctly post-repair (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm that the ABS system is functioning correctly post-repair (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: Toyota Camry C0139 Issue Resolved
Vehicle: 2012 Toyota Camry, 75,000 miles
Problem: Customer reported the ABS warning light illuminated with unusual braking behavior.
Diagnosis: Performed a visual inspection and found a damaged left rear wheel speed sensor and corroded wiring.
Solution: Replaced the left rear speed sensor and repaired the wiring harness.
Cost: $250 (sensor: $150, wiring repair: $100)
Result: Post-repair, the ABS light was cleared, and the braking system performed normally during a road test.
Case Study 2: Honda Accord ABS Sensor Replacement
Vehicle: 2015 Honda Accord, 60,000 miles
Problem: ABS light was on, and the vehicle experienced longer stopping distances.
Diagnosis: Used the GeekOBD APP to retrieve the C0139 code and test the wheel speed sensor, confirming it was faulty.
Solution: Replaced the faulty left rear wheel speed sensor with an OEM part.
Cost: $200 (sensor replacement)
Result: Post-repair testing confirmed that the ABS system was functioning correctly with no further issues.