Quick Answer
C0390 means: C0390 refers to a malfunction in the Steering Position Sensor, affecting steering performance.
Can I drive with C0390? Immediate attention is recommended to prevent further steering issues.
Common Questions
What does C0390 mean and how does it affect my car?
C0390 indicates an issue with the Steering Position Sensor, which can affect how your vehicle steers. If this sensor is faulty, it may lead to difficult or erratic steering, making it harder to control your car, especially in tight turns.
What are the most common causes of C0390 and how much does it cost to fix?
Common causes include a faulty Steering Position Sensor, wiring issues, and ECU malfunctions. Repair costs can range from $50 for wiring repairs to $300 for sensor replacement.
Can I drive my car with C0390 or should I stop immediately?
While you may be able to drive your vehicle, it's not recommended. Erratic steering can pose safety risks, especially on highways or during emergency maneuvers. It's best to have the vehicle inspected as soon as possible.
How can I diagnose C0390 myself using GeekOBD APP?
You can use the GeekOBD APP to scan for codes, view live data from the Steering Position Sensor, and check for any freeze frame data that could help you understand when the issue occurred.
What vehicles are most commonly affected by C0390?
Commonly affected vehicles include models from Chevrolet, GMC, and Cadillac from 2005 to 2015, such as the Chevy Malibu and GMC Terrain.
How can I prevent C0390 from happening again?
Regular maintenance of your vehicle's steering system, including checking for loose connections and ensuring fluid levels are appropriate, can help prevent issues with the Steering Position Sensor.
What is C0390?
The Diagnostic Trouble Code (DTC) C0390 indicates a problem with the Steering Position Sensor (SPS) in vehicles that utilize electronic power steering systems. This code typically signifies that the SPS is sending incorrect signals to the vehicle's control module, which can disrupt steering performance. This issue is commonly found in numerous models from manufacturers like Chevrolet, GMC, and Cadillac, particularly in vehicles from 2005 to 2015. A malfunctioning SPS can lead to symptoms such as erratic steering behavior, increased steering effort, or warning lights illuminating on the dashboard. If left unaddressed, it can not only impair the vehicle's drivability but also pose safety risks, as it can affect steering response during critical driving situations. The SPS is essential for accurately detecting the angle of the steering wheel and ensuring that systems like stability control and traction control function correctly. Understanding the implications of a C0390 code is crucial for vehicle owners, as timely diagnosis and repair can enhance safety and prolong the lifespan of steering components.
System: C - Chassis (ABS, Steering, Suspension)
Symptoms
Common symptoms when C0390 is present:
- The check engine light is illuminated or flashes intermittently, indicating a possible steering issue.
- Drivers may experience difficulty in steering, such as increased resistance or a 'stiff' feeling when turning the wheel.
- There may be a noticeable decrease in fuel economy, sometimes by 10-15%, due to the additional strain on the power steering system.
- Unusual noises, such as grinding or clicking, may occur when turning the steering wheel, indicating potential mechanical failure.
- The vehicle may exhibit erratic steering responses, particularly during low-speed maneuvers, which can compromise safety.
Possible Causes
Most common causes of C0390 (ordered by frequency):
- The most common cause of the C0390 code is a faulty Steering Position Sensor, which has a likelihood of about 70%. This sensor can wear out due to heat, moisture, or electrical issues.
- A second cause could be wiring issues, such as frayed cables or poor connections, leading to incorrect signals being sent to the control module. This is seen in approximately 15% of cases.
- Another cause is a malfunctioning Electronic Control Unit (ECU), which can misinterpret the sensor's data. Regular software updates can help prevent this.
- Less common but serious is a physical obstruction in the steering mechanism, like debris or damage from an accident, which can impede sensor function.
- A rare cause is a failing power steering pump, which can lead to inconsistent steering performance and contribute to the C0390 code.
C0390 Repair Costs
Cost Breakdown by Repair Type
Steering Position Sensor Replacement
Replacing the faulty Steering Position Sensor with a new OEM part.
- Total: $150 - $300
- Success rate: 90%
Wiring Repair
Repairing damaged wiring or connectors to restore proper sensor function.
- Total: $50 - $150
- Success rate: 75%
Money-Saving Tips for C0390
- 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 C0390 Diagnosis Process
Follow these systematic steps to accurately diagnose C0390. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Conduct an initial visual inspection of the steering column and wiring harness for any obvious damage or corrosion (5-10 minutes)
Step 1: Conduct an initial visual inspection of the steering column and wiring harness for any obvious damage or corrosion (5-10 minutes).
Step 2: Step 2: Use the GeekOBD APP to perform an OBD2 scan, retrieving all codes and freeze frame data to provide context for the C0390 (10-15 minutes)
Step 2: Use the GeekOBD APP to perform an OBD2 scan, retrieving all codes and freeze frame data to provide context for the C0390 (10-15 minutes).
Step 3: Step 3: Test the Steering Position Sensor using a multimeter to check for proper voltage and resistance levels (20-30 minutes)
Step 3: Test the Steering Position Sensor using a multimeter to check for proper voltage and resistance levels (20-30 minutes).
Step 4: Step 4: Perform a system function test to verify correct operation of the sensor and related systems after repairs (10-15 minutes)
Step 4: Perform a system function test to verify correct operation of the sensor and related systems after repairs (10-15 minutes).
Step 5: Step 5: Road test the vehicle under various conditions to ensure that the steering operates smoothly and that the C0390 code does not return (15-20 minutes)
Step 5: Road test the vehicle under various conditions to ensure that the steering operates smoothly and that the C0390 code does not return (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: Steering Sensor Replacement on 2013 Chevrolet Malibu
Vehicle: 2013 Chevrolet Malibu, 75,000 miles
Problem: Customer reported difficulty steering and illuminated check engine light.
Diagnosis: Diagnosed with C0390 during OBD2 scan. Visual inspection revealed a faulty steering position sensor.
Solution: Replaced the Steering Position Sensor and cleared the code.
Cost: $250 (including parts and labor)
Result: Customer reported improved steering response and no return of the check engine light.
Case Study 2: Wiring Repair on 2010 GMC Terrain
Vehicle: 2010 GMC Terrain, 90,000 miles
Problem: Vehicle exhibited erratic steering behavior and warning lights.
Diagnosis: C0390 confirmed after scan. Further inspection showed damaged wiring.
Solution: Repaired damaged wiring and ensured proper connections.
Cost: $100 (including parts and labor)
Result: Steering performance returned to normal, and no further issues were reported.