B0639 - Seat Position Sensor Circuit Range/Performance Problem in Popular Vehicles

Quick Answer

B0639 means: B0639 indicates a problem with the seat position sensor circuit, affecting seat adjustments and potentially airbag deployment.

Fix: Check and replace faulty components Cost: $150 - $300 Time: 90-180 minutes

Can I drive with B0639? Immediate attention recommended to ensure safety and comfort.

Common Questions

What does B0639 mean and how does it affect my car?

The B0639 code indicates a problem with the seat position sensor circuit. This can affect your ability to adjust the seat properly, which not only leads to discomfort but can also compromise your safety by affecting airbag deployment. Addressing this issue promptly is crucial for both comfort and safety.

What are the most common causes of B0639 and how much does it cost to fix?

The most common cause of B0639 is a faulty seat position sensor, which can cost between $150-$300 to replace. Other potential causes include damaged wiring and control module issues, which can vary in cost. It's advisable to diagnose the specific issue to understand repair costs accurately.

Can I drive my car with B0639 or should I stop immediately?

While you can technically drive your vehicle with the B0639 code, it is not recommended. Ignoring this code may lead to safety issues, particularly with airbag deployment. It's best to address the problem as soon as possible to ensure your safety.

How can I diagnose B0639 myself using GeekOBD APP?

To diagnose the B0639 code using the GeekOBD APP, first, connect the app to your vehicle's OBD2 port. Run a complete scan to retrieve the code and any related codes. Follow the app's guidance to check the seat position sensor's functionality and monitor for any abnormal readings.

What vehicles are most commonly affected by B0639?

The B0639 code is commonly found in vehicles like the 2007-2011 Chevrolet Malibu, 2008-2014 Buick LaCrosse, and 2010-2015 Chevrolet Equinox. If you own one of these models, be vigilant about any symptoms associated with this code.

How can I prevent B0639 from happening again?

To prevent the B0639 code from recurring, regularly inspect your seat adjustment mechanisms and wiring for signs of wear or damage. Keeping the interior clean and free from moisture can also help protect the electrical components from corrosion.

What is B0639?

The B0639 diagnostic trouble code (DTC) indicates that there is a performance issue or range problem with the seat position sensor circuit, which is crucial for vehicles equipped with power seats. This code is commonly found in vehicles such as the 2007-2011 Chevrolet Malibu, 2008-2014 Buick LaCrosse, and 2010-2015 Chevrolet Equinox. The seat position sensor is responsible for sending data regarding the position of the seat to the vehicle's computer, which can affect airbag deployment and other safety features. If this sensor malfunctions, not only can it lead to discomfort for the driver, but it can also trigger the airbag warning light, indicating a potential safety concern. Ignoring this code can lead to further complications, such as faulty airbag deployment during an accident or a failure to adjust the seat properly. In some cases, the vehicle may enter a reduced power mode, limiting performance until the issue is resolved. Addressing the B0639 code promptly is essential for maintaining optimal vehicle safety and comfort.

System: B - Body (Airbags, Lighting, Security, Climate Control)

Symptoms

Common symptoms when B0639 is present:

  • The seat adjustment does not respond to controls, making it difficult to find a comfortable driving position.
  • The airbag warning light illuminates on the dashboard, indicating a potential safety issue that may affect airbag deployment during an accident.
  • Increased discomfort due to improper seat positioning, leading to difficulty in reaching pedals or visibility issues.
  • The vehicle may exhibit reduced power or performance issues as a precautionary measure by the onboard computer.
  • Unusual noises may occur during seat adjustment attempts, indicating a mechanical failure in the seat adjustment system.

Possible Causes

Most common causes of B0639 (ordered by frequency):

  1. A faulty seat position sensor is the most common cause, occurring in about 60% of cases. This sensor can wear out or malfunction due to electrical issues.
  2. Wiring problems, such as damaged or corroded wires in the seat adjustment circuit, can lead to signal loss and trigger the B0639 code.
  3. A bad connection at the sensor or within the harness can cause intermittent signals, making it difficult to diagnose. Regular maintenance checks can help prevent this.
  4. Less common but serious issues include a malfunctioning body control module, which may need reprogramming or replacement if it fails to communicate with the sensor.
  5. Rarely, a complete failure of the seat adjustment motor may lead to the B0639 code, which requires replacement of the entire seat assembly.

B0639 Repair Costs

Cost Breakdown by Repair Type

Seat Position Sensor Replacement

Replacing the faulty seat position sensor is often necessary to resolve the B0639 code.

  • Total: $150 - $300
  • Success rate: 85%
Wiring Repair

Repairing or replacing damaged wiring can resolve connectivity issues between the sensor and the control module.

  • Total: $100 - $200
  • Success rate: 75%
Body Control Module Reprogramming

In rare cases, the body control module may need reprogramming to recognize the seat position sensor.

  • Total: $200 - $400
  • Success rate: 70%
Money-Saving Tips for B0639
  • 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 B0639 Diagnosis Process

Follow these systematic steps to accurately diagnose B0639. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Perform a visual inspection of the seat position sensor and wiring for any visible damage, corrosion, or loose connections (5-10 minutes)

Step 1: Perform a visual inspection of the seat position sensor and wiring for any visible damage, corrosion, or loose connections (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: Use an OBD2 scanner, such as the GeekOBD APP, to retrieve the B0639 code and any accompanying codes that may provide additional context (10-15 minutes)

Step 2: Use an OBD2 scanner, such as the GeekOBD APP, to retrieve the B0639 code and any accompanying codes that may provide additional 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: Test the seat position sensor with a multimeter to check for proper voltage and resistance, ensuring it meets the manufacturer's specifications (20-30 minutes)

Step 3: Test the seat position sensor with a multimeter to check for proper voltage and resistance, ensuring it meets the manufacturer's specifications (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: If the sensor is functioning, test the wiring harness and connectors for continuity and secure connections (15-20 minutes)

Step 4: If the sensor is functioning, test the wiring harness and connectors for continuity and secure connections (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.
Step 5: Step 5: After repairs, clear the codes using the GeekOBD APP and conduct a road test to confirm that the seat functions and the warning light remains off (15-20 minutes)

Step 5: After repairs, clear the codes using the GeekOBD APP and conduct a road test to confirm that the seat functions and the warning light remains off (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: Seat Position Sensor Replacement in 2010 Chevrolet Equinox

Vehicle: 2010 Chevrolet Equinox, 85,000 miles

Problem: The driver reported that the seat would not adjust, and the airbag warning light was illuminated.

Diagnosis: After scanning with the GeekOBD APP, the B0639 code was confirmed. A visual inspection revealed a damaged seat position sensor.

Solution: The faulty seat position sensor was replaced, and the system was recalibrated.

Cost: $225 (sensor $150, labor $75)

Result: The seat adjustments returned to normal, and the airbag warning light was cleared successfully.

Case Study 2: Wiring Repair for B0639 in 2009 Buick LaCrosse

Vehicle: 2009 Buick LaCrosse, 92,000 miles

Problem: The seat adjustment was erratic, and the airbag light was on intermittently.

Diagnosis: Using the GeekOBD APP, the B0639 code was retrieved, and a wiring inspection showed corrosion in the connectors.

Solution: Corroded connectors were replaced, and the wiring was repaired.

Cost: $180 (wiring and connectors $100, labor $80)

Result: The seat adjustment worked flawlessly after repairs, and the warning light remained off.

Diagnose B0639

Use GeekOBD APP for professional diagnosis!

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  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: B0639
System: Body (Airbags, Lighting, Security, Climate Control)
Severity: HIGH
Category: Body Codes