C0660 on Cadillac
Level Control Exhaust Valve Malfunction
C0660 on Cadillac vehicles indicates level control exhaust valve malfunction. Au7o has documented this code across 2 Cadillac models — most commonly on Escalade ESV, Seville. This chassis code indicates a malfunction in the level control (air suspension) exhaust valve circuit. On vehicles with automatic load-leveling or air suspension, the exhaust valve releases air from the suspension to lower or level the vehicle; the control module monitors the valve's electrical circuit. The code sets when that circuit is open, shorted, or otherwise out of range, so the system can no longer reliably vent air. Symptoms include a sagging, uneven, or stuck ride height and a suspension/service warning message. Typical repair costs on Cadillac range from $400 to $3,000, depending on the specific model and root cause.
Common Causes of C0660
- •Faulty level control exhaust (vent) valve
- •Open, shorted, or corroded valve wiring
- •Damaged or loose electrical connector
- •Blown fuse or relay for the suspension circuit
- •Air leak or stuck valve in the air suspension
- •Faulty suspension/level control module
- •Poor ground or low system voltage
C0660 on Cadillac by Model
Cadillac Escalade ESV(2 issues)
- Autoride Air Suspension Compressor and Shock Failure2002-2006
The Escalade ESV equipped with the Autoride electronic air suspension system experiences compressor burnout and air shock/strut failure. The compressor runs excessively trying to compensate for leaking air shocks, eventually overheating and failing. Replacement OEM air shocks are extremely expensive, and the compressor costs $800+ from the dealer. This affects the rear air shocks most commonly but front electronic struts also fail.
- Rear Air Suspension Compressor and Air Spring Failure2007-2020
The rear air ride suspension system fails frequently due to air spring leaks and compressor burnout. The air springs develop cracks in the rubber bladders, causing the rear to sag overnight. The compressor then runs continuously trying to maintain ride height, eventually burning itself out. This is extremely common after 80,000 miles.
Cadillac Seville(1 issue)
- Electronic Continuously Variable Real-Time Damping Strut Failure1998-2004
The Magneride/ECS (Electronic Controlled Suspension) struts are expensive and fail, causing a harsh ride, clunking, and "Service Ride Control" messages. The struts use magnetorheological fluid that degrades over time, losing its ability to adjust damping. Replacement OEM struts are very costly.
Looking for C0660 on a different make?
View C0660 across all makes →Frequently Asked Questions
What does C0660 mean on Cadillac?▼
C0660 stands for "Level Control Exhaust Valve Malfunction." This chassis code indicates a malfunction in the level control (air suspension) exhaust valve circuit. On vehicles with automatic load-leveling or air suspension, the exhaust valve releases air from the suspension to lower or level the vehicle; the control module monitors the valve's electrical circuit. The code sets when that circuit is open, shorted, or otherwise out of range, so the system can no longer reliably vent air. Symptoms include a sagging, uneven, or stuck ride height and a suspension/service warning message. On Cadillac specifically, this code is documented across 2 models.
What causes C0660 on Cadillac vehicles?▼
Common causes on Cadillac: Faulty level control exhaust (vent) valve, Open, shorted, or corroded valve wiring, Damaged or loose electrical connector, Blown fuse or relay for the suspension circuit, Air leak or stuck valve in the air suspension. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix C0660 on a Cadillac?▼
Repair costs on Cadillac range from $400 to $3,000, depending on the specific model and root cause.
Which Cadillac models have C0660 documented?▼
Au7o has documented C0660 on 2 Cadillac models: Escalade ESV, Seville.