What Does C0662 Mean?
This code indicates the suspension control module has detected an abnormally low voltage or resistance in the level control exhaust valve circuit, which is part of an automatic leveling suspension system. The exhaust valve releases air pressure from the air springs to lower the vehicle or maintain proper ride height. The module detected voltage below the expected threshold, indicating a short to ground, open circuit, or failed valve coil.
Common Causes
40%
Damaged wiring harness or connector with short to ground in the exhaust valve circuit
35%
Failed level control exhaust valve solenoid with internal short or open coil
15%
Corroded or damaged connector pins at exhaust valve causing poor contact or intermittent short
10%
Faulty suspension control module with internal driver circuit failure
Diagnostic Steps
1
Step 1: Perform visual inspection of the exhaust valve wiring harness and connector for chafing, pinching, corrosion, or damage. Check for water intrusion and verify connector is fully seated with intact locking tabs.
2
Step 2: Disconnect the exhaust valve connector and measure resistance across the valve solenoid terminals using a multimeter. Typical specification is 3-8 ohms; infinite resistance indicates an open coil, near-zero indicates a short.
3
Step 3: With valve disconnected, measure voltage on the control wire from the module at the harness side connector using a multimeter while commanding valve activation through scan tool active test. Should see battery voltage when commanded on, 0V when off.
4
Step 4: Check for short to ground by measuring resistance between each control wire terminal at the harness connector and vehicle ground with valve disconnected and ignition off. Should read infinite resistance; low resistance confirms short to ground in harness.
5
Step 5: If wiring and valve test good, inspect compressor assembly and air lines for proper exhaust valve mounting and air leaks. Verify valve operates mechanically by applying direct battery voltage momentarily and listening for valve actuation click.
6
Step 6: Clear codes, cycle ignition, command exhaust valve operation through active tests, and monitor live data for proper voltage readings. Verify repair by road testing vehicle through full suspension travel and confirming no code return.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
This code indicates the suspension control module has detected an abnormally low voltage or resistance in the level control exhaust valve circuit, which is part of an automatic leveling suspension system. The exhaust valve releases air pressure from the air springs to lower the vehicle or maintain p...
The most common cause of C0662 (Level Control Exhaust Valve Circuit Low) is: Damaged wiring harness or connector with short to ground in the exhaust valve circuit
Typical repair costs for C0662 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive but may experience improper ride height, sagging rear end when loaded, or inability to self-level. Extended driving with this condition may cause uneven tire wear and reduced handling stability, especially when loaded. Repair within 1-2 weeks recommended.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C0662 to identify the root cause.
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Quick Info
Category
Chassis
System
Suspension System - Active Level Control
Difficulty
Type
Generic (SAE)
Recommended Tools
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