AutoCodes – Generic – C0665

C0665 Code - Level Control Compressor Relay Malfunction

Quick Answer

The Electronic Suspension Control (ESC) module monitors a lift/dive signal at the Powertrain Control Module (PCM). Common causes include Faulty Level Control Compressor Relay, Level Control Compressor Relay harness is open or shorted, Level Control Compressor Relay 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: C0665 indicates Level Control Compressor Relay Malfunction.
Common causes: Common causes include Faulty Level Control Compressor Relay, Level Control Compressor Relay harness is open or shorted, Level Control Compressor Relay 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 1,414

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 Jul 31, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code C0665 Description

The Electronic Suspension Control (ESC) module monitors a lift/dive signal at the Powertrain Control Module (PCM). Under normal conditions, the ESC module supplies a 5-volt reference voltage to the PCM. The PCM grounds this circuit when the vehicle is accelerating rapidly (LIFT) or braking hard (DIVE). When the lift/dive signal goes low (approximately 0-volts), the ESC module commands all four ESC dampers to a FIRM condition.

OBDII Code C0665 - Level Control Compressor Relay Malfunction - AutoCodes.com — C0665 Code - Level Control Compressor Relay Malfunction

What does this mean?

What are the Possible Causes of the DTC C0665?

Faulty Level Control Compressor Relay
Level Control Compressor Relay harness is open or shorted
Level Control Compressor Relay circuit poor electrical connection

How to Fix the DTC C0665?

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 C0665 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 C0665 code?

Need more information on how to fix the C0665 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C0665 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C0665 Buick — Level Control Compressor Relay Malfunction
C0665 Cadillac — Level Control Compressor Relay Malfunction
C0665 Chevrolet — Level Control Compressor Relay Malfunction
C0665 GMC — Level Control Compressor Relay Malfunction

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 C0665 Code

1. What are common symptoms of OBDII code C0665 (Level Control Compressor Relay Malfunction)?

- Common symptoms include issues with the vehicle's suspension system, uneven ride height, and illumination of the Service Suspension System warning light.

2. What can cause the OBDII code C0665 to trigger?

- The code C0665 is typically triggered by a malfunction in the level control compressor relay, which may be caused by a faulty relay, wiring issues, or a problem with the compressor itself.

3. How can I diagnose the cause of OBDII code C0665?

- To diagnose the cause of code C0665, it is recommended to perform a thorough inspection of the level control compressor relay, check the wiring for any damage, and test the compressor for proper functionality.

4. Is it safe to drive with OBDII code C0665 active?

- It is generally not recommended to drive with code C0665 active as it may lead to issues with the vehicle's suspension system and affect its ride quality. It is advisable to address the issue promptly.

5. How can I repair OBDII code C0665 at home?

- Repairing code C0665 may involve replacing the level control compressor relay, repairing any damaged wiring, or addressing any issues with the compressor. If you are familiar with automotive repairs, you may be able to tackle this issue at home.

6. Can a faulty level control compressor relay cause other problems in the vehicle?

- Yes, a faulty level control compressor relay can cause issues with the vehicle's suspension system, affecting ride comfort, stability, and overall driving experience.

7. Is it common for the level control compressor relay to fail?

- While failures of the level control compressor relay are not extremely common, they can occur due to factors like age, wear, or electrical issues.

8. Will resetting the OBDII code C0665 make it go away permanently?

- Resetting the code may temporarily turn off the warning light, but if the underlying issue causing code C0665 is not addressed, the code is likely to reappear.

9. Can a mechanic help diagnose and repair OBDII code C0665?

- Yes, a qualified mechanic can diagnose the cause of code C0665 using specialized tools and expertise, and perform the necessary repairs to resolve the issue effectively.

10. How important is it to fix OBDII code C0665 promptly?

- It is important to address code C0665 promptly to prevent further damage to the vehicle's suspension system and ensure optimal ride quality and safety while driving.