Introduction:
The C0660 diagnostic trouble code (DTC) indicates a malfunction within the level control exhaust valve circuit of a vehicle's suspension system. This system, often found in vehicles equipped with air suspension, is responsible for maintaining proper ride height and stability. A malfunctioning exhaust valve can lead to issues with ride quality, handling, and even damage to other suspension components.
Table: C0660 - Level Control Exhaust Valve Circuit Malfunction
| Category | Description | Possible Causes |
|---|---|---|
| Code Definition | C0660 - Level Control Exhaust Valve Circuit Malfunction | Electrical fault in the exhaust valve circuit |
| System Affected | Level Control/Air Suspension System | Vehicle's ride height adjustment system |
| Symptoms | Vehicle sitting too low or unevenly Air compressor running constantly Suspension warning light illuminated Rough or bouncy ride Inability to adjust ride height Possible hissing sound near the exhaust valve | |
| Possible Causes | Faulty level control exhaust valve Open or shorted wiring in the exhaust valve circuit Poor electrical connection at the exhaust valve connector Corroded wiring or connectors Faulty suspension control module (SCM) Blown fuse or faulty relay in the air suspension system Air leak in the exhaust valve assembly Internal valve failure (mechanical) | |
| Diagnostic Steps | Visual inspection of the exhaust valve and wiring Checking for air leaks around the valve Testing the exhaust valve for proper operation (resistance, voltage) Checking the wiring harness for continuity and shorts Scanning the SCM for other related DTCs Testing the SCM output signal to the exhaust valve Inspecting the fuse and relay associated with the air suspension system Using a scan tool to monitor exhaust valve operation | |
| Common Parts to Check/Replace | Level control exhaust valve Wiring harness connector Air suspension fuse Air suspension relay * Suspension Control Module (SCM) (less common) | |
| Severity | Moderate to High | Can lead to further suspension damage if not addressed |
| Related Codes | C0615 - Level Control Compressor Circuit Malfunction C0620 - Level Control Vent Solenoid Circuit Malfunction C0635 - Level Control Front Height Sensor Circuit Malfunction C0640 - Level Control Rear Height Sensor Circuit Malfunction * C0690 - Level Control System Performance | |
| Tools Needed | Scan tool with ABS/Suspension diagnostics Multimeter Wiring diagram Basic hand tools (sockets, wrenches, screwdrivers) * Air leak detector (optional) | |
| Estimated Repair Cost | Varies widely depending on the failed component. Exhaust valve replacement can range from $200-$800, while SCM replacement can be significantly higher. Labor costs will also vary. | |
| Preventative Measures | Regularly inspect the air suspension system for leaks Avoid overloading the vehicle Address any suspension issues promptly Protect wiring harnesses from damage |
Detailed Explanations:
Code Definition: C0660 - Level Control Exhaust Valve Circuit Malfunction indicates an electrical problem in the circuit that controls the exhaust valve for the vehicle's level control system. This means the system has detected an unexpected voltage or resistance reading in the circuit.
System Affected: The Level Control/Air Suspension System is responsible for automatically adjusting the vehicle's ride height to maintain a level and comfortable ride, regardless of load. It uses sensors, a compressor, air springs, and valves to achieve this.
Symptoms: The symptoms of a C0660 code can vary, but common signs include the vehicle sitting too low, especially on one side, the air compressor running excessively, illumination of the suspension warning light on the dashboard, a rough ride, inability to adjust ride height, and a possible hissing sound from an air leak near the exhaust valve.
Possible Causes: A faulty level control exhaust valve is a primary suspect. Other causes include open or shorted wiring in the circuit, poor electrical connections due to corrosion or damage, a faulty suspension control module (SCM), a blown fuse or relay, an air leak in the exhaust valve assembly, or a mechanical failure within the valve itself.
Diagnostic Steps: Start with a thorough visual inspection of the exhaust valve and its wiring. Check for air leaks around the valve using soapy water or an electronic leak detector. Test the valve's resistance and voltage using a multimeter. Inspect the wiring harness for continuity and shorts. Scan the SCM for other related DTCs. Test the SCM's output signal to the valve. Check the fuse and relay associated with the air suspension system. Finally, use a scan tool to monitor the valve's operation in real-time.
Common Parts to Check/Replace: The most common part to replace is the level control exhaust valve itself. Other parts to inspect and potentially replace include the wiring harness connector, the air suspension fuse and relay, and, in rare cases, the suspension control module (SCM).
Severity: The severity of a C0660 code is moderate to high. While the vehicle may still be drivable, the compromised suspension can lead to further damage to other suspension components, affecting handling and safety.
Related Codes: Related codes can provide valuable clues for diagnosing the problem. C0615 indicates a compressor circuit malfunction, C0620 points to a vent solenoid circuit issue, C0635 and C0640 relate to front and rear height sensor circuit problems, and C0690 signals a general level control system performance issue.
Tools Needed: To diagnose and repair a C0660 code, you'll need a scan tool with ABS/Suspension diagnostics capabilities, a multimeter for electrical testing, wiring diagrams for the vehicle, basic hand tools, and optionally, an air leak detector.
Estimated Repair Cost: The repair cost can vary widely depending on the failed component and the labor rate of the repair shop. Replacing the exhaust valve can range from $200 to $800, while replacing the SCM can be significantly more expensive.
Preventative Measures: Regularly inspect the air suspension system for leaks, especially around the air springs and valve assemblies. Avoid overloading the vehicle, as this puts extra strain on the suspension system. Address any suspension issues promptly to prevent further damage. Protect wiring harnesses from damage by ensuring they are properly secured and shielded.
Frequently Asked Questions:
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What does the C0660 code mean? It indicates a malfunction in the electrical circuit controlling the level control exhaust valve.
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Can I drive my car with a C0660 code? While you might be able to drive, it's not recommended as it can lead to further suspension damage and compromise safety.
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Is the exhaust valve the same as the compressor? No, the exhaust valve releases air from the system, while the compressor pumps air into it.
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How do I check for air leaks in the suspension system? You can use soapy water or an electronic leak detector to identify leaks around air springs, valves, and fittings.
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Can a blown fuse cause the C0660 code? Yes, a blown fuse in the air suspension system circuit can prevent the exhaust valve from operating correctly.
Conclusion:
The C0660 code signifies a problem within the level control exhaust valve circuit, impacting the vehicle's air suspension system. Thorough diagnosis and repair are crucial to restore proper ride height and handling, preventing further damage and ensuring a safe driving experience. Always consult a qualified technician if you are unsure about any aspect of the diagnosis or repair process.