What Does U0139 Mean?
The control module network has lost communication with Suspension Control Module B, a secondary suspension control unit. This typically indicates a vehicle with multiple suspension control modules managing different axles or advanced suspension features.
Common Causes
35%
Suspension Control Module B internal failure or power loss
30%
Damaged or corroded wiring harness and connectors
20%
CAN bus circuit fault or network communication error
10%
Module mounting location water intrusion or environmental damage
5%
Ground circuit fault or high resistance ground connection
Diagnostic Steps
1
Step 1: Locate Suspension Control Module B and verify power supply voltage and ground integrity
2
Step 2: Inspect module and connector for physical damage, water intrusion, or corrosion
3
Step 3: Measure CAN bus voltage at module connector during key-on engine-off and engine running
4
Step 4: Test CAN High and CAN Low circuit continuity to other modules on network
5
Step 5: Compare live data from Suspension Control Module A (if present) to determine if network-wide issue
Estimated Repair Cost
$200 - $1,600
Parts + labor, varies by vehicle and location
The control module network has lost communication with Suspension Control Module B, a secondary suspension control unit. This typically indicates a vehicle with multiple suspension control modules managing different axles or advanced suspension features.
The most common cause of U0139 (Lost Communication With Suspension Control Module "B") is: Suspension Control Module B internal failure or power loss
Typical repair costs for U0139 range from $200 to $1,600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Adaptive suspension features will be disabled or operate in default mode, resulting in degraded ride quality and handling response. Vehicle remains safe to drive but comfort and stability are compromised.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0139 to identify the root cause.
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Quick Info
Category
Network
System
Active Suspension/Damping System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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