Lost Communication With Battery Cooling Fan Module
The U0271 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Battery Cooling Fan Module. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $300 - $1,200 (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 pack running hot
- Charging speed limited due to temperature
- Fan not running when battery is warm
- Battery temperature warning light on
Probable Causes (Ranked by Likelihood)
- Failed battery cooling fan motor Very High
- Fan control module failure High
- CAN bus wiring fault Moderate
- Clogged cooling fan intake Low
Step-by-Step Diagnostic Procedure
-
Check cooling fan operation manually
-
Inspect fan intake for debris
-
Scan fan module for codes
-
Test fan motor with direct power
Frequently Asked Questions
Can I drive with U0271?
Short distances only. Monitor battery temperature and stop if warnings appear.
What causes U0271?
Usually a failed fan motor or clogged intake. Module failure is also possible.
Why is battery cooling important?
Excessive heat accelerates battery degradation and can be a safety risk.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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