What Does C1842 Mean?
The air suspension control module has detected a short to battery voltage on the disable switch circuit. The module is seeing unwanted voltage on the switch input line, which may prevent proper switch state detection. The air suspension warning light will be illuminated, and the system may enter a default operating mode.
Common Causes
35%
Disable switch circuit wire chafed against a power source or crossed with a battery-voltage wire in the harness
25%
Disable switch connector has cross-contamination or bridging between the signal pin and a nearby power pin
20%
Aftermarket accessory wiring (trunk light, amp, etc.) spliced into or contacting the disable switch circuit
10%
Water intrusion into the switch or connector creating a conductive path to a power source
10%
Control module input protection circuit has failed
Diagnostic Steps
1
Disconnect the disable switch connector and measure voltage on the module side of the harness — if battery voltage is present with the switch disconnected, the short is between the switch connector and the module.
2
With the switch disconnected and no voltage present, reconnect and recheck — if voltage now appears, the switch itself is providing an unwanted voltage path.
3
Inspect the switch circuit wiring for any aftermarket splices, taps, or modifications, particularly in the trunk area where audio amplifiers, trailer wiring, or auxiliary lights may have been installed.
4
Examine the full wiring path for areas where the disable switch wire runs alongside power distribution wires and check for chafed or melted insulation.
5
Check the switch connector for moisture, corrosion, or debris that could bridge terminals.
Estimated Repair Cost
$30 - $350
Parts + labor, varies by vehicle and location
The air suspension control module has detected a short to battery voltage on the disable switch circuit. The module is seeing unwanted voltage on the switch input line, which may prevent proper switch state detection. The air suspension warning light will be illuminated, and the system may enter a d...
The most common cause of C1842 (Air Suspension Disable Switch Circuit Short To Battery) is: Disable switch circuit wire chafed against a power source or crossed with a battery-voltage wire in the harness
Typical repair costs for C1842 range from $30 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle is safe to drive with this fault present. The air suspension system may operate normally or enter a limited mode depending on the vehicle. The short is unlikely to cause further damage but should be repaired to restore normal switch functionality.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1842 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Chassis
System
Air Suspension System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
