AutoCodes – Generic – B27C4

B27C4 Code - A/C Unit Case Temperature Sensor Low

Quick Answer

The Diagnostic Trouble Code (DTC) sets when the A/C unit case temperature sensor recognition temperature is too low [less than - 42Â°C (- 44Â°F)]. Common causes include Faulty A/C Unit Case Temperature Sensor, A/C Unit Case Temperature Sensor harness is open or shorted, A/C Unit Case Temperature Sensor 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: B27C4 indicates A/C Unit Case Temperature Sensor Low.
Common causes: Common causes include Faulty A/C Unit Case Temperature Sensor, A/C Unit Case Temperature Sensor harness is open or shorted, A/C Unit Case Temperature Sensor 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 458

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 10, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B27C4 Description

The Diagnostic Trouble Code (DTC) sets when the A/C unit case temperature sensor recognition temperature is too low [less than - 42Â°C (- 44Â°F)].

OBDII Code B27C4 - A/C Unit Case Temperature Sensor Low - AutoCodes.com — B27C4 Code - A/C Unit Case Temperature Sensor Low

What does this mean?

What are the Possible Causes of the DTC B27C4?

Faulty A/C Unit Case Temperature Sensor
A/C Unit Case Temperature Sensor harness is open or shorted
A/C Unit Case Temperature Sensor circuit poor electrical connection
Faulty A/C Auto Amplifier

How to Fix the DTC B27C4?

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 B27C4 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 B27C4 code?

Need more information on how to fix the B27C4 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B27C4 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B27C4 Infiniti — A/C Unit Case Temperature Sensor Low
B27C4 Nissan — A/C Unit Case Temperature Sensor Low

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 B27C4 Code

1. What are the common symptoms of OBDII code B27C4 - A/C Unit Case Temperature Sensor Low?

- Common symptoms include poor air conditioning performance, inconsistent cooling, and potential activation of the A/C system's safety features.

2. What can cause the OBDII code B27C4 to trigger the A/C Unit Case Temperature Sensor Low error?

- This code is usually triggered by a faulty or malfunctioning A/C unit case temperature sensor, which may be sending incorrect temperature readings to the vehicle's computer.

3. How can I diagnose the A/C Unit Case Temperature Sensor Low issue associated with code B27C4?

- Diagnosing this issue typically involves using a scan tool to read the specific code, testing the A/C unit case temperature sensor for proper operation, and checking the sensor's wiring for any faults.

4. Can a dirty or blocked A/C evaporator cause the B27C4 code to appear?

- Yes, a dirty or blocked A/C evaporator can cause incorrect temperature readings and potentially trigger the A/C Unit Case Temperature Sensor Low error code.

5. What are some repair tips for fixing the OBDII code B27C4 related to the A/C Unit Case Temperature Sensor Low?

- Repair tips may include cleaning or replacing the A/C unit case temperature sensor, checking and cleaning the A/C evaporator, and ensuring all sensor wiring connections are secure.

6. Is it safe to continue driving with the OBDII code B27C4 active?

- It is generally not recommended to continue driving with this code active, as it can lead to poor A/C performance and potentially cause further damage to the cooling system.

7. Can resetting the OBDII code B27C4 resolve the A/C Unit Case Temperature Sensor Low issue?

- Resetting the code may temporarily clear the error, but it will likely reappear if the underlying issue with the A/C unit case temperature sensor is not addressed.

8. How much does it typically cost to repair the A/C Unit Case Temperature Sensor Low issue associated with code B27C4?

- The cost of repair can vary depending on the exact cause of the issue, but it may involve sensor replacement, cleaning, or wiring repairs, with costs ranging from $100 to $300 or more.

9. Are there any DIY methods to troubleshoot or fix the OBDII code B27C4 at home?

- DIY methods may include visually inspecting the sensor and its wiring, cleaning the A/C evaporator, and using a multimeter to test sensor functionality, although professional diagnosis and repair are often recommended.

10. Can a low refrigerant level in the A/C system trigger the A/C Unit Case Temperature Sensor Low code B27C4?

- While low refrigerant levels can affect A/C performance, the specific trigger for code B27C4 is usually related to issues with the A/C unit case temperature sensor rather than refrigerant levels.