AutoCodes – Generic – C1780

C1780 Code - Temperature Select Switch Failure

Quick Answer

The Engine Control Module (ECM) monitors the Temperature Select Switch. Common causes include Faulty Temperature Select Switch, Temperature Select Switch harness is open or shorted, Temperature Select Switch 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: C1780 indicates Temperature Select Switch Failure.
Common causes: Common causes include Faulty Temperature Select Switch, Temperature Select Switch harness is open or shorted, Temperature Select Switch 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 4,048

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 Nov 26, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C1780 Description

The Engine Control Module (ECM) monitors the Temperature Select Switch. The ECM sets the OBDII code when the Temperature Select Switch is not to factory specifications.

OBDII Code C1780 - Temperature Select Switch Failure - AutoCodes.com — C1780 Code - Temperature Select Switch Failure

What does this mean?

What are the Possible Causes of the DTC C1780?

Faulty Temperature Select Switch
Temperature Select Switch harness is open or shorted
Temperature Select Switch circuit poor electrical connection

How to Fix the DTC C1780?

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 C1780 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 C1780 code?

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Need Help with the Code?

Get the C1780 code diagnosed by a professional: Find a repair shop in your area

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 C1780 Code

1. What are the common symptoms of OBDII code C1780 (Temperature Select Switch Failure)?

The common symptoms of OBDII code C1780 include issues with the heating or cooling system not responding to temperature adjustments, inconsistent temperature output, or the HVAC system failing to switch between hot and cold air.

2. What are the possible causes of OBDII code C1780?

The possible causes of OBDII code C1780 (Temperature Select Switch Failure) include a faulty temperature select switch, wiring issues, a malfunctioning HVAC control module, or a problem with the blend door actuator.

3. How can I diagnose OBDII code C1780 at home?

To diagnose OBDII code C1780 at home, you can start by checking the temperature select switch for any visible damage or loose connections. You can also use an OBDII scanner to retrieve the specific error code and further troubleshoot the HVAC system.

4. What are the repair options for OBDII code C1780?

Repair options for OBDII code C1780 may include replacing the temperature select switch, repairing any damaged wiring, recalibrating the HVAC control module, or replacing the blend door actuator if necessary.

5. Can OBDII code C1780 be reset without fixing the underlying issue?

Resetting OBDII code C1780 without fixing the underlying issue is not recommended, as the problem will likely persist and may lead to further issues with the HVAC system. It is best to diagnose and repair the root cause of the code to ensure proper functionality.

6. Will driving with OBDII code C1780 cause any damage to the vehicle?

Continuing to drive with OBDII code C1780 may not cause immediate damage to the vehicle, but it can lead to discomfort due to improper temperature control and may impact the overall performance of the HVAC system. It is advisable to address the issue promptly.

7. How much does it typically cost to repair OBDII code C1780?

The cost of repairing OBDII code C1780 can vary depending on the root cause of the issue, the extent of the repair needed, and the labor rates of the auto repair shop. It is recommended to obtain quotes from different service providers for an accurate estimate.

8. Can a DIY enthusiast fix OBDII code C1780 at home?

A DIY enthusiast with knowledge of automotive repairs may be able to fix OBDII code C1780 at home, especially if the issue is related to a simple fix like replacing the temperature select switch. However, more complex issues may require professional assistance.

9. Are there any preventive maintenance tips to avoid OBDII code C1780 in the future?

To prevent OBDII code C1780 in the future, it is recommended to regularly inspect the HVAC system, address any temperature control issues promptly, and follow the manufacturer's maintenance schedule for the heating and cooling components.

10. How urgent is it to address OBDII code C1780?

While OBDII code C1780 may not pose an immediate safety risk, addressing it in a timely manner is important to ensure the proper functioning of the HVAC system and to avoid potential discomfort while driving. It is advisable to address the issue at the earliest convenience.