C0477 - Steering Angle Sensor Range/Performance Problem in GM Vehicles

Quick Answer

C0477 means: DTC C0477 signifies a problem with the steering angle sensor's range or performance.

Fix: Check and replace faulty components Cost: $150 - $600 Time: 90-180 minutes

Can I drive with C0477? Immediate attention is recommended to avoid safety risks.

Common Questions

What does C0477 mean and how does it affect my car?

C0477 signifies a malfunction in the steering angle sensor, which is crucial for your vehicle's stability and safety systems. If your steering feels off or warning lights appear, it's important to get this checked to avoid potential accidents.

What are the most common causes of C0477 and how much does it cost to fix?

Common causes include a faulty steering angle sensor, damaged wiring, or misalignment. Repair costs typically range from $150 to $600, depending on the specific issue and repairs needed.

Can I drive my car with C0477 or should I stop immediately?

While you may be able to drive short distances, it is not recommended. Erratic steering can lead to dangerous situations, so addressing this code as soon as possible is crucial for your safety.

How can I diagnose C0477 myself using GeekOBD APP?

Using GeekOBD APP, you can scan for DTCs, review freeze frame data, and monitor live sensor readings. Focus on the steering angle sensor's data to check for inconsistencies.

What vehicles are most commonly affected by C0477?

This code is commonly seen in GM vehicles, such as the Chevrolet Silverado (2014-2019), GMC Sierra (2014-2019), and Cadillac Escalade (2015-2020).

How can I prevent C0477 from happening again?

Regular maintenance, including inspections of the steering system and electrical components, can help prevent C0477. Keeping the vehicle's software updated is also essential.

What is C0477?

The diagnostic trouble code (DTC) C0477 indicates that there is a problem with the steering angle sensor's range or performance, particularly in vehicles such as the Chevrolet Silverado (2014-2019), GMC Sierra (2014-2019), and Cadillac Escalade (2015-2020). This sensor is crucial for various systems in your vehicle, including stability control and collision avoidance systems. When the sensor malfunctions or provides incorrect readings, it can lead to erratic steering behavior, which may compromise safety. This issue typically surfaces when the vehicle's onboard diagnostics detect a discrepancy in the sensor's output compared to expected values. Real-world implications include the potential for reduced steering responsiveness and a higher risk of losing control of the vehicle in adverse conditions. It's important to address this code promptly, as failure to do so can lead to further complications within the vehicle's electronic systems, potentially increasing repair costs and safety hazards. Drivers may notice symptoms such as the illumination of the 'Service Stabilitrak' or 'Service ESC' warning lights on the dashboard, which indicates that the electronic stability control system is disabled due to sensor-related issues. Regular maintenance and inspections can help prevent this problem from occurring.

System: C - Chassis (ABS, Steering, Suspension)

Symptoms

Common symptoms when C0477 is present:

  • The 'Service Stabilitrak' warning light illuminates on the dashboard, indicating a problem with the stability control system.
  • 'Check Engine' light remains on continuously, often accompanied by other warning lights.
  • Steering feels unresponsive or overly sensitive, making the vehicle difficult to control, especially during sharp turns.
  • The vehicle may exhibit erratic steering behavior, where it feels like the car is pulling to one side.
  • Increased tire wear may occur due to improper alignment or steering response.

Possible Causes

Most common causes of C0477 (ordered by frequency):

  1. The most common cause is a faulty steering angle sensor, which occurs in about 60% of cases. This can stem from wear and tear or electrical issues.
  2. Corroded or damaged wiring leading to the sensor can cause inaccurate readings, making up about 20% of cases. Inspect wiring harnesses for signs of wear.
  3. A misaligned or improperly calibrated steering angle sensor can also trigger C0477; this can be prevented by regular maintenance checks.
  4. Less common but serious causes include failure in the power steering control module, which may require extensive diagnostics.
  5. Rarely, software glitches in the vehicle's computer systems can lead to erroneous readings, requiring a software update or reprogramming.

C0477 Repair Costs

Cost Breakdown by Repair Type

Steering Angle Sensor Replacement

Replacing the faulty steering angle sensor to restore proper function.

  • Total: $150 - $600
  • Success rate: 85%
Wiring Repair

Repairing or replacing damaged wiring that affects sensor performance.

  • Total: $100 - $300
  • Success rate: 75%
Software Update

Updating the vehicle's control module software to fix glitches.

  • Total: $50 - $150
  • Success rate: 70%
Money-Saving Tips for C0477
  • 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 C0477 Diagnosis Process

Follow these systematic steps to accurately diagnose C0477. 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).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
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).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the steering angle sensor and related wiring (20-30 minutes)

Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the steering angle sensor and related wiring (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes, ensuring all systems communicate correctly (10-15 minutes)

Step 4: System function test - Verify proper operation after repairs and clear codes, ensuring all systems communicate correctly (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure no warning lights remain illuminated (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure no warning lights remain illuminated (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

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 Angle Sensor Replacement in a 2017 Chevrolet Silverado

Vehicle: 2017 Chevrolet Silverado, 45,000 miles

Problem: Customer reported that the 'Service Stabilitrak' light was illuminated and steering felt unresponsive.

Diagnosis: OBD2 scan revealed code C0477. Visual inspection showed the steering angle sensor was faulty.

Solution: Replaced the steering angle sensor and recalibrated the system.

Cost: $450 (sensor $300, labor $150)

Result: Post-repair, the warning light was cleared, and the customer reported improved steering responsiveness.

Case Study 2: Wiring Repair on a 2018 GMC Sierra

Vehicle: 2018 GMC Sierra, 30,000 miles

Problem: Customer experienced erratic steering and multiple warning lights on the dashboard.

Diagnosis: Diagnostic testing revealed C0477 due to damaged wiring harness connecting to the steering angle sensor.

Solution: Repaired wiring and replaced connectors as needed.

Cost: $200 (wiring repair $100, labor $100)

Result: Vehicle operated normally post-repair, with no further issues reported.

Diagnose C0477

Use GeekOBD APP for professional diagnosis!

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Code Information

Code: C0477
System: Chassis (ABS, Steering, Suspension)
Severity: HIGH
Category: Chassis Codes