OBD2 Code C1798: Rear Right Air Spring Solenoid Short to Ground
The C1798 code indicates a short-to-ground fault in the output circuit of the rear right air spring solenoid in an air suspension system. The suspension control module detects an abnormally low voltage or excessive current draw to ground on the solenoid drive circuit, preventing proper control of air spring pressure. When the module commands the solenoid to actuate, the return voltage does not change as expected, confirming a current leak to chassis ground. This causes the system to disable height adjustment for that wheel to protect the control circuit, potentially leading to vehicle lean and illumination of the suspension warning light.
1. Commonly Affected Makes
2. Most Common Causes
- Short to ground in the rear right solenoid wiring
- Damaged rear right air spring solenoid with shorted coils
- Corroded, bent, or damaged terminals in the solenoid electrical connector
- Control circuit wiring rubbing against body or chassis
- Internal failure in the air suspension control module (RAS module)
3. Symptoms You Will Notice
- Vehicle leaning to one side, especially the rear right
- Suspension warning light illuminated on the dashboard
4. Step-by-Step Diagnosis
Scan for codes and verify C1798 is present
Visually inspect the rear right solenoid wiring and connector for damage, corrosion, or chafing
Measure resistance between solenoid control circuit and ground; a low reading indicates a short
Disconnect the solenoid and check for continuity to ground on the harness side; if short persists, repair wiring; if not, replace solenoid
If wiring and solenoid are good, test the suspension control module output; replace module if faulty
5. Frequently Asked Questions
Is it safe to drive?▼
Driving is not recommended because the fault can cause unstable handling and further damage to the suspension system. Have it repaired as soon as possible.
How much does it cost to fix?▼
Repair costs typically range from $200 to $800, depending on whether the issue is a wiring repair (lower end) or solenoid/module replacement (higher end).