What Does C1918 Mean?
The air suspension module has detected a circuit failure in the ride height select switch. This switch allows the driver to choose between normal and raised (off-road) ride height settings. The module cannot read the switch position, so it defaults to the last known or normal ride height setting, preventing the driver from commanding a ride height change.
Common Causes
35%
Failed ride height select switch with worn internal contacts or broken detent mechanism
30%
Open or damaged wiring between the switch and the air suspension module
25%
Corroded or loose connector at the switch or module due to dashboard moisture or drink spills
10%
Air suspension module internal switch input circuit failure
Diagnostic Steps
1
Step 1: Operate the ride height select switch and listen/feel for the normal detent click. A mushy or non-clicking switch suggests mechanical failure.
2
Step 2: Measure the switch circuit voltage at the module connector while toggling the switch. The voltage should change between distinct levels (e.g., 0V, 2.5V, 5V) for each position.
3
Step 3: Check the switch connector behind the instrument panel for loose pins, corrosion, or disconnection.
4
Step 4: Measure continuity from the switch connector to the air suspension module connector to verify wiring integrity.
5
Step 5: If wiring and switch test good, substitute a known-good switch to confirm the fault. Replace and clear codes.
Estimated Repair Cost
$50 - $300
Parts + labor, varies by vehicle and location
The air suspension module has detected a circuit failure in the ride height select switch. This switch allows the driver to choose between normal and raised (off-road) ride height settings. The module cannot read the switch position, so it defaults to the last known or normal ride height setting, pr...
The most common cause of C1918 (Air Suspension Ride Height Select Switch Circuit Failure) is: Failed ride height select switch with worn internal contacts or broken detent mechanism
Typical repair costs for C1918 range from $50 to $300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is a convenience feature fault. The vehicle will operate at its default ride height. There is no immediate safety concern, but the inability to raise ride height for off-road conditions could lead to underbody damage on rough terrain.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1918 to identify the root cause.
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Quick Info
Category
Chassis
System
Air Suspension System
Difficulty
Type
Manufacturer
Recommended Tools
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