C1870 Air Suspension Gate Solenoid Open Circuit
The C1870 code indicates an open circuit condition in the air suspension gate solenoid. The air suspension control module has detected a loss of electrical continuity in the circuit that powers the solenoid, preventing the voltage signal from reaching the component or completing the circuit properly. This fault occurs when the circuit resistance exceeds the manufacturer's maximum threshold, commonly found in luxury vehicles equipped with air suspension systems.
1. Commonly Affected Makes
2. Most Common Causes
- Damaged air suspension gate solenoid with an open internal coil
- Broken or cut wiring in the control circuit
- Corroded, bent, or misaligned pins in the electrical connector
- Blown air suspension circuit fuse
3. Symptoms You Will Notice
- Air suspension warning light illuminated on the dashboard
- Vehicle may sag or sit unevenly, especially after being parked
- Air suspension may not adjust ride height properly
- Compressor may run continuously or fail to operate
4. Step-by-Step Diagnosis
Scan for additional codes and verify C1870 is present
Visually inspect the gate solenoid connector and wiring for damage, corrosion, or loose connections
Test the solenoid resistance with a multimeter; compare to manufacturer specifications
Check for voltage at the solenoid connector with the ignition on; if no voltage, inspect the fuse and control module output
If wiring and solenoid are good, test the control module for proper output or replace if necessary
5. Frequently Asked Questions
Is it safe to drive?▼
Driving with code C1870 is not recommended for long distances. The vehicle may experience uneven ride height or loss of suspension control, which can affect handling and safety. It's best to have it diagnosed and repaired promptly.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on the root cause. A simple fuse or connector repair may be under $200, while replacing the solenoid or control module can cost $400–$800 or more.