Rear Left Shock Actuator Circuit Malfunction
The C1905 code indicates that the suspension control module has detected an electrical fault in the circuit for the left rear shock absorber actuator. This actuator is part of the ride control system and adjusts the damping or stiffness of the left rear shock based on driving conditions. The fault may be caused by abnormal solenoid resistance, an open circuit, or a short circuit in the wiring, preventing the module from properly controlling the shock's valve or solenoid.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty left rear shock actuator or actuator resistance out of specification
- Open circuit, short to ground, or short to voltage in the left rear actuator circuit
- Corroded, disconnected, or damaged pins at the actuator connector
- Intermittent suspension control module failure (less common)
3. Symptoms You Will Notice
- Illuminated Check Engine Light or suspension warning light
- Reduced ride quality or uneven damping, especially on the left rear
4. Step-by-Step Diagnosis
Scan for codes and verify C1905 is present
Inspect the left rear actuator connector for corrosion, damage, or loose connection
Measure resistance of the actuator solenoid; compare to manufacturer specifications
Check for open or short circuits in the wiring between the module and actuator
If wiring and actuator are good, test the suspension control module for proper output
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but you may notice reduced ride quality. The vehicle remains drivable, but have it diagnosed soon to prevent further issues.
How much does it cost to fix?▼
Typically $200 to $600, depending on whether the actuator or wiring needs replacement and labor rates.