Lost Communication With Differential Control Module
The U0278 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Differential Control Module. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $400 - $1,800 (parts and labor)
Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.
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Common Symptoms
- AWD or 4WD system warning light on
- Limited slip differential not engaging
- Torque vectoring disabled
- Differential lock indicator off
Probable Causes (Ranked by Likelihood)
- Failed differential control module Very High
- Differential actuator failure High
- CAN bus wiring to differential Moderate
- Low differential fluid Low
Step-by-Step Diagnostic Procedure
-
Check differential fluid level
-
Scan differential module for codes
-
Test differential actuator operation
-
Inspect CAN bus wiring to module
Frequently Asked Questions
Can I drive with U0278?
Short distances on paved roads. Avoid off-road or slippery conditions.
What causes U0278?
Usually a failed differential control module or actuator.
How much does U0278 cost to fix?
Between $400 and $1,800 depending on the component.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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