What is an OBD2 code?

An OBD2 (On-Board Diagnostics) code is a diagnostic trouble code (DTC) generated by your vehicle's computer system when it detects a problem. These codes help identify specific issues with your vehicle's engine, transmission, emissions, or other systems.

How do I read OBD2 codes?

To read OBD2 codes, you'll need an OBD2 scanner. Plug it into your vehicle's OBD2 port (usually located under the dashboard), turn your key to the 'ON' position, and follow your scanner's instructions to retrieve the codes. Each code starts with a letter (P, B, C, or U) followed by four numbers.

What do the different types of OBD2 codes mean?

OBD2 codes are categorized by their first letter: P (Powertrain) for engine and transmission issues, B (Body) for interior systems like airbags, C (Chassis) for mechanical systems like brakes, and U (Network) for computer and module communication problems.

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Home » OBD2 Codes » C0668

Code C0668

Symptoms

• Bumpy or uncomfortable ride

• Vehicle sits unevenly

• Warning light on the dashboard

Common Causes

• Faulty level control solenoid

• Damaged wiring or connectors in the solenoid circuit

• Defective suspension control module

Glossary

Solenoid: An electromechanical device used to control a mechanism.

Suspension: The system of springs and shock absorbers that smooths out a vehicle's ride.

Related Codes

• C0660

• C0661

Laymans terms

This code means there's a problem with the car's suspension system. It's like when a bike's shock absorber isn't working right, so the ride gets bumpy.

Explanation

C0668 indicates an issue with the suspension control system, specifically related to the level control solenoid circuit.

Technical description

The C0668 code is triggered when the suspension control module detects a malfunction in the level control solenoid circuit. This solenoid is responsible for adjusting the vehicle's suspension height to maintain a smooth ride.

Diagnosis steps

• Inspect the level control solenoid and its wiring for damage.

• Test the solenoid for proper operation using a multimeter.

• Check the suspension control module for faults.

Repair procedures

• Replace the faulty level control solenoid.

• Repair or replace damaged wiring or connectors.

• Replace the suspension control module if necessary.

Tools required

• Multimeter

• OBD-II scanner

• Basic hand tools

Estimated repair cost

$150 - $500

Difficulty level

Moderate

Commonly affected vehicles

• Chevrolet Tahoe

• GMC Yukon

• Cadillac Escalade

Preventive measures

• Regularly inspect suspension components.

• Ensure wiring is intact and secure.

• Perform routine maintenance checks.

Error code type

Suspension System Issue

User experience recommendations

• Avoid driving on rough roads until repaired.

• Get the suspension checked by a professional.

• Monitor for any changes in vehicle handling.

Warranty information

Check with your vehicle manufacturer for warranty coverage on suspension components.

Historical data

C0668 has been reported in vehicles with air suspension systems, particularly in older models.

Urgency level

Moderate – It affects ride comfort and handling, but is not immediately dangerous.

Legal and safety notice

Driving with a faulty suspension can lead to handling issues and increased wear on other components.

Testing conditions

• Vehicle parked on a level surface

• Ignition in the ON position

Component location

The level control solenoid is typically located near the air suspension struts or shocks.

FAQs

Q: Can I drive with a C0668 code?
A: It's possible to drive, but it may be uncomfortable and could lead to further damage.

Q: How do I reset the C0668 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue persists, the code will return.

Last updated: Feb 7, 2026 • Source: internal database

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