B0420 - DTC B0420 - Understanding the Air Conditioning Temperature Sensor Range/Performance Code in Popular Cars

Quick Answer

B0420 means: B0420 indicates an issue with the air conditioning temperature sensor range or performance.

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

Can I drive with B0420? While it's not an immediate danger to drive, neglecting this code can lead to reduced A/C efficiency and higher repair costs.

Common Questions

What does B0420 mean and how does it affect my car?

The B0420 code indicates a problem with the air conditioning temperature sensor, which can lead to inefficient A/C performance. This affects your comfort while driving and can lead to higher fuel consumption if not addressed.

What are the most common causes of B0420 and how much does it cost to fix?

Common causes of B0420 include a faulty A/C temperature sensor, wiring issues, and a malfunctioning A/C control module. Repair costs typically range from $100 to $300 depending on the nature of the fix.

Can I drive my car with B0420 or should I stop immediately?

While it is safe to drive with the B0420 code, you may experience reduced A/C performance. It’s advisable to address the issue soon to avoid further complications.

How can I diagnose B0420 myself using GeekOBD APP?

Using the GeekOBD APP, you can scan for codes, view freeze frame data, and check live sensor readings to diagnose A/C issues. Look for abnormal temperature readings to identify potential problems.

What vehicles are most commonly affected by B0420?

Vehicles such as the 2010-2015 Chevrolet Equinox, 2011-2015 Ford Explorer, and 2012-2016 Honda Accord often experience the B0420 code, especially in older models.

How can I prevent B0420 from happening again?

Regular maintenance of your A/C system, including checking refrigerant levels and replacing worn sensors, can help prevent the recurrence of the B0420 code.

What is B0420?

The diagnostic trouble code (DTC) B0420 indicates a malfunction in the air conditioning (A/C) temperature sensor circuit, specifically pointing to an issue with the temperature sensor's range or performance. This code can trigger in various vehicles, particularly in models such as the 2010-2015 Chevrolet Equinox, 2011-2015 Ford Explorer, and the 2012-2016 Honda Accord. When the vehicle's onboard computer detects that the A/C temperature sensor is providing readings outside of the expected range, it sets the B0420 code. This can lead to poor A/C performance, causing the cabin to become uncomfortably hot or cold. Additionally, the check engine light may illuminate as a warning to the driver. Ignoring this issue can lead to further complications, including unnecessary strain on the A/C system and potentially costly repairs down the line. It is crucial for vehicle owners to address this code promptly to ensure optimal performance of their air conditioning system and maintain comfort within the vehicle. Regular maintenance, including checking the A/C system and ensuring the temperature sensor is functioning correctly, can help prevent the occurrence of this DTC in the future.

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

Symptoms

Common symptoms when B0420 is present:

The check engine light is illuminated, indicating a malfunction in the A/C system.
Inconsistent A/C performance, where the cabin temperature does not match the selected temperature settings.
Unusual noises from the A/C system, which may indicate that the compressor is working harder than necessary due to sensor issues.
Increased fuel consumption, as the A/C system may strain the engine if it operates inefficiently due to faulty sensors.
Frequent cycling of the A/C compressor, which can lead to premature wear and eventual failure of components.

Possible Causes

Most common causes of B0420 (ordered by frequency):

Faulty A/C temperature sensor (60% likelihood) - The most common issue is a defective temperature sensor that fails to provide accurate readings to the vehicle's computer.
Wiring issues (20% likelihood) - Damaged or corroded wiring in the sensor circuit can lead to incorrect signals being sent, triggering the B0420 code.
Faulty A/C control module (10% likelihood) - A malfunction in the A/C control module can misinterpret sensor data, affecting performance.
Refrigerant level problems (5% likelihood) - Low refrigerant levels can cause sensor readings to go awry, though this is less common.
Less common causes (5% likelihood) - Other electronic issues, such as a malfunctioning engine control unit (ECU), may also lead to this code being set.

B0420 Repair Costs

Cost Breakdown by Repair Type

A/C Temperature Sensor Replacement

Replacing the faulty A/C temperature sensor can resolve the B0420 code.

Total: $100 - $300
Success rate: 95%

Wiring Repair

Repairing damaged wiring or connectors in the A/C sensor circuit.

Total: $50 - $150
Success rate: 85%

Money-Saving Tips for B0420

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 B0420 Diagnosis Process

Follow these systematic steps to accurately diagnose B0420. 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 related to the A/C temperature sensor (5-10 minutes)

Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion related to the A/C temperature sensor (5-10 minutes).