What Does C1885 Mean?
The air suspension control module has detected a general circuit failure in the right rear height sensor. The RR sensor provides ride height feedback for the rear axle, and this fault indicates the module cannot obtain a valid height reading from that corner. The system may disable rear leveling or enter full fault mode, particularly impacting load-leveling capability when carrying cargo or towing.
Common Causes
35%
Failed RR height sensor with worn potentiometer or damaged Hall-effect element producing no valid signal output
30%
Corroded or damaged wiring in the RR height sensor circuit, commonly from road salt and moisture exposure in the rear undercarriage
25%
Disconnected or broken height sensor link arm at the RR corner preventing mechanical input to the sensor
10%
Air suspension control module internal circuit failure on the RR height sensor input channel
Diagnostic Steps
1
Step 1: Locate the RR height sensor (typically mounted on the rear axle or trailing arm with a link to the body). Check for physical damage, missing link arm, or loose mounting.
2
Step 2: Backprobe the sensor signal wire with ignition on and manually cycle the rear suspension. Voltage should sweep smoothly between 0.5V and 4.5V. No change or erratic output indicates sensor failure.
3
Step 3: Verify 5V reference and ground are present at the sensor connector. Missing reference voltage points to a wiring issue or module fault.
4
Step 4: Check connector and wiring for corrosion, especially at the rear where exposure to road spray is highest. Measure continuity of all three sensor wires back to the module.
5
Step 5: Compare RR height sensor live data to the LR sensor value. Both should read within specification at normal ride height. If RR is absent or wildly different, replace the sensor.
Estimated Repair Cost
$120 - $550
Parts + labor, varies by vehicle and location
The air suspension control module has detected a general circuit failure in the right rear height sensor. The RR sensor provides ride height feedback for the rear axle, and this fault indicates the module cannot obtain a valid height reading from that corner. The system may disable rear leveling or ...
The most common cause of C1885 (Air Suspension RR Height Sensor Circuit Failure) is: Failed RR height sensor with worn potentiometer or damaged Hall-effect element producing no valid signal output
Typical repair costs for C1885 range from $120 to $550, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Loss of the RR height sensor disables accurate rear ride height management, which is especially problematic when the vehicle is loaded or towing. Uneven rear height can cause poor handling and headlight misaim.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1885 to identify the root cause.
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Quick Info
Category
Chassis
System
Air Suspension System
Difficulty
Type
Manufacturer
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