AutoCodes – Generic – B2771

B2771 Code - PTC Heater Overheat Protect

Quick Answer

A Positive Temperature Coefficient (PTC) heater is used as the heat source for heating. Common causes include Faulty Positive Temperature Coefficient (PTC) Heater, PTC Heater harness is open or shorted, PTC Heater circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B2771 indicates PTC Heater Overheat Protect.
Common causes: Common causes include Faulty Positive Temperature Coefficient (PTC) Heater, PTC Heater harness is open or shorted, PTC Heater circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,109

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Feb 04, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B2771 Description

A Positive Temperature Coefficient (PTC) heater is used as the heat source for heating. The PTC is a ceramic material with barium titanate as the primary component. The PTC heater provides an internal control circuit and performs LIN communication with A/C Auto Amplifier. Based on the signals from A/C Auto Amplifier, the microcomputer inside PTC heater controls the heater output by PWM. When current is applied, it heats up. Upon reaching a certain temperature (Curie temperature) the resistance suddenly increases, limiting the current, and maintaining a constant amount of heating. The Diagnostic Trouble Code (DTC) sets when the PTC heater circuit board internal temperature is 115°C (239°F) or more.

OBDII Code B2771 - PTC Heater Overheat Protect - AutoCodes.com — B2771 Code - PTC Heater Overheat Protect

What does this mean?

What are the Possible Causes of the DTC B2771?

Faulty Positive Temperature Coefficient (PTC) Heater
PTC Heater harness is open or shorted
PTC Heater circuit poor electrical connection

How to Fix the DTC B2771?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B2771 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B2771 code?

Need more information on how to fix the B2771 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B2771 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B2771 Nissan — PTC Heater Overheat Protect

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B2771 Code

1. What are the common symptoms of OBDII code B2771 (PTC Heater Overheat Protect)?

The common symptoms of B2771 include the heater not functioning properly, reduced heating performance, and potential overheating of the PTC heater.

2. What are the potential causes of the PTC Heater Overheat Protect code B2771?

Common causes of B2771 include a faulty PTC heater, issues with the heater control circuit, or a malfunctioning temperature sensor.

3. How can I diagnose the PTC Heater Overheat Protect code B2771?

Diagnosing B2771 involves checking the PTC heater for proper operation, inspecting the heater control circuit for any faults, and testing the temperature sensor for accuracy.

4. Can driving with the B2771 code cause further damage to the vehicle?

Continuing to drive with the B2771 code can potentially lead to further damage to the PTC heater system and may result in overheating issues, reduced heating performance, or complete heater failure.

5. How can I repair the PTC Heater Overheat Protect code B2771?

Repairing B2771 may involve replacing the faulty PTC heater, repairing any issues in the heater control circuit, or replacing a malfunctioning temperature sensor.

6. Is it safe to clear the B2771 trouble code without addressing the underlying issue?

It is not recommended to clear the B2771 trouble code without addressing the underlying problem, as it may lead to continued heating system issues and potential safety hazards.

7. Are there any preventive maintenance tips to avoid OBDII code B2771?

Regularly inspecting and servicing the heating system, checking for any signs of overheating, and addressing any heating system issues promptly can help prevent the occurrence of B2771.

8. Can extreme weather conditions contribute to triggering the PTC Heater Overheat Protect code B2771?

Extreme weather conditions, such as extremely cold temperatures, can put additional strain on the heating system and potentially contribute to triggering the B2771 trouble code.

9. Can a DIY enthusiast fix the B2771 code, or is it recommended to seek professional help?

While some enthusiasts with experience in automotive repair may be able to diagnose and repair the B2771 code, seeking professional help from a certified mechanic is recommended for a more accurate and thorough repair.

10. How long does it typically take to repair the OBDII code B2771 (PTC Heater Overheat Protect)?

The repair time for B2771 can vary depending on the specific issue causing the code, but it may take anywhere from a few hours to a full day to diagnose, repair, and test the heating system properly.