What Does U0518 Mean?
The vehicle network is receiving invalid data from door switch module 'C', usually the left rear door. Communication data from this module contains errors or values outside normal operating parameters.
Common Causes
35%
Failed rear door control module or switch assembly
30%
Corroded or broken wiring in rear door harness, particularly at hinge area
20%
Water intrusion into rear door module from window or seal leak
10%
Defective door ajar switch or lock mechanism causing erratic signals
5%
Ground circuit fault or CAN bus termination issue affecting rear doors
Diagnostic Steps
1
Step 1: Access rear door module data using scan tool and operate door switches, locks, and windows while monitoring for corrupt data
2
Step 2: Inspect rear door harness at hinge points for wire damage from repeated door cycles or accident damage
3
Step 3: Remove rear door trim panel and examine module connector for water damage, corrosion, or loose connections
4
Step 4: Test child safety lock switch if equipped, as this can send invalid data when failing
5
Step 5: Check ground circuit continuity and CAN bus signal integrity at rear door module connector
Estimated Repair Cost
$150 - $700
Parts + labor, varies by vehicle and location
The vehicle network is receiving invalid data from door switch module 'C', usually the left rear door. Communication data from this module contains errors or values outside normal operating parameters.
The most common cause of U0518 (Invalid Data Received From "Door Switch C") is: Failed rear door control module or switch assembly
Typical repair costs for U0518 range from $150 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Rear door functions including child locks, power locks, windows, and ajar detection may fail. Generally does not affect driving safety but may compromise passenger security.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0518 to identify the root cause.
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Quick Info
Category
Network
System
Body Control Network
Difficulty
Type
Generic (SAE)
Recommended Tools
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