B0377 - Seat Heater Circuit Short to Ground - Common in 2015-2020 Chevrolet and GMC Models

Quick Answer

B0377 means: B0377 indicates a short to ground in the seat heater circuit.

Fix: Check and replace faulty components Cost: $100 - $300 Time: 90-180 minutes

Can I drive with B0377? It is advisable to diagnose and repair this issue promptly to avoid further electrical problems.

Common Questions

What does B0377 mean and how does it affect my car?

The B0377 code indicates a short to ground in the seat heater circuit, which may result in malfunctioning heated seats. This can lead to discomfort during winter months and may pose a risk of electrical issues if left unaddressed.

What are the most common causes of B0377 and how much does it cost to fix?

The common causes include damaged wiring (60%), faulty seat heater elements (25%), and corrosion (10%). Repair costs range from $100 for wiring repairs to $500 for element replacements.

Can I drive my car with B0377 or should I stop immediately?

While it is generally safe to drive with this code, it's advisable to get it diagnosed quickly to avoid potential electrical fires or further damage.

How can I diagnose B0377 myself using GeekOBD APP?

Using the GeekOBD APP, connect to your vehicle's OBD2 port, scan for error codes, and review freeze frame data to understand the circumstances under which the B0377 code was triggered.

What vehicles are most commonly affected by B0377?

Commonly affected vehicles include the 2015-2020 Chevrolet Silverado, GMC Sierra, and various Cadillac models. Be sure to check for any recalls or technical service bulletins related to the seat heater system.

How can I prevent B0377 from happening again?

Regularly inspect seat wiring for signs of wear, ensure moisture does not accumulate around the seat area, and conduct routine maintenance on your vehicle's electrical system.

What is B0377?

The diagnostic trouble code (DTC) B0377 indicates a problem with the seat heater circuit. Specifically, it signals that there is a short to ground in the wiring or components associated with the seat heater system. This code is typically found in various Chevrolet and GMC vehicles manufactured between 2015 and 2020. When the vehicle’s onboard diagnostic system detects abnormal resistance or a direct short in the seat heater circuit, it triggers the B0377 code, causing the check engine light to illuminate. This can affect the functionality of the heated seats, leading to them not heating properly or not functioning at all. In some cases, if the short is severe enough, it could potentially result in damage to the seat heater components or the vehicle's electrical system. Ignoring this DTC can lead to further complications, including increased repair costs and safety issues if the wiring short leads to overheating. Therefore, it's essential to address this code promptly to ensure the safe and comfortable operation of your vehicle's heating system.

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

Symptoms

Common symptoms when B0377 is present:

  • The check engine light remains illuminated, indicating a fault in the vehicle's system.
  • The heated seats fail to operate, leading to discomfort during cold weather driving conditions.
  • There may be an unusual smell or odor, possibly indicating overheating wiring.
  • Fuses related to the heated seat system may blow frequently, interrupting functionality.
  • In some cases, the driver may notice that the seat heater activates intermittently or not at all.

Possible Causes

Most common causes of B0377 (ordered by frequency):

  1. The most common cause is damaged wiring or connectors leading to a short circuit, which can occur in about 60% of cases. This is often due to wear and tear or improper installation during repairs.
  2. A malfunctioning seat heater element itself can cause a short to ground, accounting for approximately 25% of B0377 occurrences. This may require replacement of the seat cushion or backrest.
  3. Corrosion or poor connections in the electrical system can lead to intermittent faults, making up about 10% of cases. Regular inspections can help prevent this.
  4. Less common but serious causes include issues with the climate control module, which can affect multiple components if not addressed.
  5. Rarely, a faulty body control module (BCM) may misinterpret signals, leading to false B0377 codes.

B0377 Repair Costs

Cost Breakdown by Repair Type

Wiring Repair

Repair or replacement of damaged wiring and connectors related to the seat heater circuit.

  • Total: $100 - $300
  • Success rate: 85%
Seat Heater Element Replacement

Replacement of a faulty seat heater element, which may require disassembly of the seat.

  • Total: $200 - $500
  • Success rate: 90%
Body Control Module (BCM) Repair

Repair or reprogramming of the BCM if it is misinterpreting signals.

  • Total: $300 - $800
  • Success rate: 70%
Money-Saving Tips for B0377
  • 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 B0377 Diagnosis Process

Follow these systematic steps to accurately diagnose B0377. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Step 1: Initial visual inspection - Perform a quick check for damaged wiring, loose connections, or corrosion, which can take about 5-10 minutes

Step 1: Initial visual inspection - Perform a quick check for damaged wiring, loose connections, or corrosion, which can take about 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 - Connect the app to your vehicle to retrieve all codes and freeze frame data, understanding the full context of the fault (10-15 minutes)

Step 2: OBD2 scan with GeekOBD APP - Connect the app to your vehicle to retrieve all codes and freeze frame data, understanding the full context of the fault (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 - Utilize a multimeter or specialized seat heater diagnostic tool to test the wiring and seat heater elements for continuity (20-30 minutes)

Step 3: Component testing - Utilize a multimeter or specialized seat heater diagnostic tool to test the wiring and seat heater elements for continuity (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 - After repairs, verify the operation of the seat heater and clear any fault codes to ensure the issue is resolved (10-15 minutes)

Step 4: System function test - After repairs, verify the operation of the seat heater and clear any fault codes to ensure the issue is resolved (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 the success of the repair and ensure the seat heater operates correctly (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm the success of the repair and ensure the seat heater operates correctly (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 Heater Repair on 2018 Chevrolet Silverado

Vehicle: 2018 Chevrolet Silverado, 45,000 miles

Problem: Customer reported that the driver’s side heated seat was not functioning.

Diagnosis: Diagnosed using the GeekOBD APP, revealing a B0377 code. Visual inspection showed frayed wiring under the seat.

Solution: Repaired the damaged wiring harness and reconnected loose terminals.

Cost: $150 for wiring repair.

Result: Heated seat functionality restored, and no further issues noted during follow-up.

Case Study 2: Faulty Seat Heater Element in 2019 GMC Sierra

Vehicle: 2019 GMC Sierra, 30,000 miles

Problem: Customer noticed that the passenger seat heater was intermittent.

Diagnosis: Used the GeekOBD APP to identify the B0377 code and tested the seat heater element, finding it was shorted.

Solution: Replaced the seat heater element and tested for proper operation.

Cost: $400 for seat heater element replacement.

Result: Passenger seat heater now works consistently, customer satisfied with the repair.

Diagnose B0377

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: B0377
System: Body (Airbags, Lighting, Security, Climate Control)
Severity: MEDIUM
Category: Body Codes