What Does C1904 Mean?
The ride control module has detected a short-to-ground in the right rear shock actuator circuit. The control wire is making contact with chassis ground, preventing the module from energizing the solenoid. The RR shock will default to its base damping setting and cannot be adjusted, resulting in asymmetric ride control.
Common Causes
40%
Actuator control wire insulation worn through from contact with rear suspension or body components
25%
Internal actuator solenoid short to the shock body/ground path
25%
Water intrusion into the actuator connector creating a ground path
10%
Pinched wire at a harness clip or body panel grounding the control circuit
Diagnostic Steps
1
Step 1: Disconnect the RR shock actuator and measure resistance from each control wire to chassis ground. Below 10k ohms confirms a ground fault in the wiring.
2
Step 2: Measure solenoid resistance from each terminal to the shock body. Low resistance indicates an internal actuator short.
3
Step 3: Trace the harness from actuator to module, looking for worn insulation contacting metal components, particularly near the shock mount and wheel well.
4
Step 4: Inspect the connector for water damage and corrosion. Dry and apply dielectric grease.
5
Step 5: Repair the short, clear codes, and verify proper actuator operation through all damping modes.
Estimated Repair Cost
$150 - $850
Parts + labor, varies by vehicle and location
The ride control module has detected a short-to-ground in the right rear shock actuator circuit. The control wire is making contact with chassis ground, preventing the module from energizing the solenoid. The RR shock will default to its base damping setting and cannot be adjusted, resulting in asym...
The most common cause of C1904 (Ride Control RR Shock Actuator Circuit Short To Ground) is: Actuator control wire insulation worn through from contact with rear suspension or body components
Typical repair costs for C1904 range from $150 to $850, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The RR shock remains in its default damping mode, creating asymmetric suspension behavior. While not immediately dangerous, handling may be unpredictable, especially on rough roads at higher speeds.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1904 to identify the root cause.
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Quick Info
Category
Chassis
System
Electronic Ride Control / Adaptive Suspension
Difficulty
Type
Manufacturer
Recommended Tools
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