B0404 - Understanding the B0404 Code in 2015-2020 Chevrolet and GMC Models

Quick Answer

B0404 means: B0404 indicates a malfunction with the A/C refrigerant temperature sensor.

Fix: Check and replace faulty components Cost: $150 - $250 Time: 90-180 minutes

Can I drive with B0404? Address promptly to avoid further A/C system damage.

Common Questions

What does B0404 mean and how does it affect my car?

The B0404 code signifies that there’s a problem with the A/C refrigerant temperature sensor. This can impact your vehicle's ability to provide adequate heating or cooling, especially during extreme weather. If not addressed, it could lead to further A/C system issues and discomfort while driving.

What are the most common causes of B0404 and how much does it cost to fix?

Common causes of the B0404 code include a faulty refrigerant temperature sensor, wiring issues, and refrigerant leaks. Repair costs can range from $150 to $250 for sensor replacement, while wiring repairs may cost between $100 and $200.

Can I drive my car with B0404 or should I stop immediately?

While you can drive your vehicle with the B0404 code, it is advisable to address the issue soon. Continuing to drive may exacerbate the problem, potentially leading to costly repairs down the line.

How can I diagnose B0404 myself using GeekOBD APP?

To diagnose the B0404 code using the GeekOBD APP, connect the device to your vehicle’s OBD2 port, run a diagnostic scan, and review the codes and freeze frame data. Look for any additional codes that might indicate related issues, and check the sensor's performance using the APP's live data feature.

What vehicles are most commonly affected by B0404?

The B0404 code is commonly reported in 2015-2020 Chevrolet Silverado and GMC Sierra models, as well as other vehicles from General Motors during this period. Always check for any manufacturer recalls or technical service bulletins related to the A/C system.

How can I prevent B0404 from happening again?

Regular maintenance of your A/C system, including periodic inspections and recharging, can help prevent the B0404 code. Additionally, keep an eye on refrigerant levels and address any leaks promptly to ensure the longevity of your A/C components.

What is B0404?

The B0404 diagnostic trouble code (DTC) is a specific error code that indicates an issue within the air conditioning system, particularly related to the A/C refrigerant temperature sensor. This code can be particularly common in vehicles such as the 2015-2020 Chevrolet Silverado and GMC Sierra. When the vehicle's onboard computer detects a problem with the refrigerant temperature sensor, it triggers the check engine light, prompting the driver to investigate further. The refrigerant temperature sensor monitors the temperature of the refrigerant in the A/C system. If the sensor fails or if there are wiring issues, the system can't properly regulate the temperature, leading to inadequate cooling or heating performance. In real-world terms, this means that your vehicle’s A/C may not work efficiently, potentially leaving you uncomfortable in hot weather. Ignoring this code could lead to further damage to the A/C system and increased repair costs down the line. Therefore, understanding and addressing the B0404 code promptly is crucial for maintaining your vehicle's comfort and avoiding costly repairs.

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

Symptoms

Common symptoms when B0404 is present:

  • Check engine light stays on constantly, indicating a fault in the A/C system.
  • A/C blows warm air instead of cold, which is a direct result of the temperature sensor malfunction.
  • Erratic A/C performance, where the cooling seems inconsistent, can lead to discomfort during drives.
  • Increased fuel consumption, which can occur if the A/C system is running inefficiently.
  • Unusual noises from the A/C compressor, indicating that it may be working harder than necessary.

Possible Causes

Most common causes of B0404 (ordered by frequency):

  1. The most common cause is a faulty A/C refrigerant temperature sensor, which accounts for about 60% of B0404 instances. This sensor can fail due to age, wear, or external damage.
  2. Wiring issues, including frayed wires or poor connections in the sensor circuit, can lead to false readings and trigger the B0404 code.
  3. A refrigerant leak in the system can also impact the sensor's readings, significantly affecting A/C performance.
  4. Less common but serious causes include a failing A/C compressor, which may lead to severe system damage if not addressed.
  5. Rarely, a malfunctioning engine control module (ECM) could cause the B0404 code, leading to erroneous sensor readings.

B0404 Repair Costs

Cost Breakdown by Repair Type

A/C Refrigerant Temperature Sensor Replacement

Replacing the faulty refrigerant temperature sensor to restore proper A/C operation.

  • Total: $150 - $250
  • Success rate: 85%
Wiring Repair

Repairing or replacing damaged wiring associated with the A/C sensor.

  • Total: $100 - $200
  • Success rate: 75%
A/C System Recharge

Recharging the A/C system if a refrigerant leak was found.

  • Total: $75 - $150
  • Success rate: 70%
Money-Saving Tips for B0404
  • 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 B0404 Diagnosis Process

Follow these systematic steps to accurately diagnose B0404. 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 around the A/C components (5-10 minutes)

Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion around the A/C components (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

Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context. This will give a clearer picture of the A/C's operational status (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 to test the A/C refrigerant temperature sensor's resistance to ensure it's within specifications (20-30 minutes)

Step 3: Component testing - Use a multimeter to test the A/C refrigerant temperature sensor's resistance to ensure it's within 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: System function test - After repairs, verify proper operation of the A/C system and clear codes using the GeekOBD APP (10-15 minutes)

Step 4: System function test - After repairs, verify proper operation of the A/C system and clear codes using the GeekOBD APP (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 A/C system's performance and ensure the B0404 code does not return (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm the A/C system's performance and ensure the B0404 code does not return (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: Chevrolet Silverado 2018 A/C System Failure

Vehicle: 2018 Chevrolet Silverado 1500, 50,000 miles

Problem: Customer reported the A/C blowing warm air and the check engine light was on.

Diagnosis: Using the GeekOBD APP, retrieved a B0404 code. A visual inspection revealed a frayed wire connected to the A/C refrigerant temperature sensor.

Solution: Replaced the damaged wire and the refrigerant temperature sensor, followed by a system recharge.

Cost: $230 (sensor: $150, wiring repair: $80)

Result: A/C function restored to normal, and the check engine light was cleared.

Case Study 2: GMC Sierra 2019 A/C Performance Issues

Vehicle: 2019 GMC Sierra 1500, 30,000 miles

Problem: The customer noted inconsistent cooling from the A/C system and a persistent B0404 code.

Diagnosis: Diagnostic testing indicated a faulty A/C refrigerant temperature sensor.

Solution: Replaced the sensor; no wiring issues were found. A system recharge was performed after the replacement.

Cost: $200 (sensor: $150, recharge: $50)

Result: The A/C system was fully functional post-repair, and the customer reported satisfaction with the performance.

Diagnose B0404

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: B0404
System: Body (Airbags, Lighting, Security, Climate Control)
Severity: MEDIUM
Category: Body Codes