Lost Communication With Battery State of Health Module
The U0266 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Battery State of Health Module. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $300 - $1,500 (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
- Battery health status unavailable
- State of health reading showing error
- Battery warranty tracking not functioning
- Degradation data not recording
Probable Causes (Ranked by Likelihood)
- Failed battery SOH monitoring module Very High
- CAN bus communication fault High
- Battery cell sensor array failure Moderate
- Software error in SOH algorithm Low
Step-by-Step Diagnostic Procedure
-
Scan SOH module for diagnostic codes
-
Check battery cell sensor connections
-
Test CAN bus at SOH module connector
-
Verify module software version
Frequently Asked Questions
Can I drive with U0266?
Short distances. The battery still works but its health cannot be monitored.
What causes U0266?
Usually a failed SOH monitoring module or cell sensor failure.
Why is battery SOH important?
It tracks battery degradation over time, which affects range and may be needed for warranty claims.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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