AutoCodes – Generic – B1231

B1231 Code - Open In The Evaporator Temperature Sensor Circuit

Quick Answer

The Climate Control Unit monitors the Evaporator Temperature Sensor. Common causes include Faulty Evaporator Temperature Sensor, Evaporator Temperature Sensor harness is open or shorted, Evaporator Temperature Sensor circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: B1231 indicates Open In The Evaporator Temperature Sensor Circuit.
Common causes: Common causes include Faulty Evaporator Temperature Sensor, Evaporator Temperature Sensor harness is open or shorted, Evaporator Temperature Sensor circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 31,196

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 19, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1231 Description

The Climate Control Unit monitors the Evaporator Temperature Sensor. The Climate Control Unit sets the OBDII code when the Evaporator Temperature Sensor is not to factory specifications.

OBDII Code B1231 - Open In The Evaporator Temperature Sensor Circuit - AutoCodes.com — B1231 Code - Open In The Evaporator Temperature Sensor Circuit

What does this mean?

What are the Possible Causes of the DTC B1231?

Faulty Evaporator Temperature Sensor
Evaporator Temperature Sensor harness is open or shorted
Evaporator Temperature Sensor circuit poor electrical connection
Faulty Climate Control Unit

How to Fix the DTC B1231?

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 B1231 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 B1231 code?

Need more information on how to fix the B1231 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1231 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B1231 Acura — Open In The Evaporator Temperature Sensor Circuit
B1231 Chrysler — PTS Sensor 8 Circuit Low
B1231 Dodge — PTS Sensor 8 Circuit Low
B1231 Honda — Open In The Evaporator Temperature Sensor Circuit
B1231 Jeep — PTS Sensor 8 Circuit Low
B1231 RAM — PTS Sensor 8 Circuit 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 B1231 Code

1. What are the common symptoms of OBDII code B1231 (Open In The Evaporator Temperature Sensor Circuit)?

- Common symptoms include inconsistent air conditioning performance, failure of the AC system to cool properly, and the AC compressor not engaging.

2. What are some possible causes of the B1231 code?

- Possible causes include a faulty evaporator temperature sensor, damaged wiring or connectors in the sensor circuit, or a problem with the AC control module.

3. How can I diagnose the issue causing the B1231 code?

- To diagnose the issue, you can use a multimeter to test the resistance of the evaporator temperature sensor, check for continuity in the sensor circuit, and inspect the wiring and connectors for any damage.

4. Can I repair the B1231 code issue myself?

- Depending on your skill level and access to tools, you may be able to repair the issue yourself by replacing the evaporator temperature sensor, repairing damaged wiring or connectors, or resetting the AC control module.

5. Is it safe to continue driving with the B1231 code present?

- It is generally not recommended to continue driving with the B1231 code present, as it can lead to further damage to the AC system and compromise your comfort while driving.

6. How much does it typically cost to repair the B1231 code?

- The cost of repairing the B1231 code can vary depending on the specific cause of the issue, but it may range from $100 to $300 for parts and labor.

7. Can the B1231 code be triggered by other issues unrelated to the evaporator temperature sensor?

- While the B1231 code is specifically related to an open circuit in the evaporator temperature sensor, other underlying issues in the AC system can potentially trigger this code as well.

8. Will resetting the OBDII system clear the B1231 code?

- Resetting the OBDII system may temporarily clear the B1231 code, but if the underlying issue is not addressed, the code is likely to reappear once the problem is detected again.

9. How important is it to address the B1231 code promptly?

- It is important to address the B1231 code promptly to ensure proper functioning of the AC system, maintain comfort while driving, and prevent potential damage to other components in the system.

10. Can a mechanic use a scan tool to diagnose the B1231 code?

- Yes, a mechanic can use a scan tool to read the B1231 code, retrieve additional diagnostic information, and help pinpoint the exact cause of the issue in the evaporator temperature sensor circuit.