U0220 critical

Lost Communication With EV Traction Battery Module A

The U0220 code means the vehicle's onboard diagnostic system has detected: Lost Communication With EV Traction Battery Module A. This is a critical severity code.

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Keep driving?
No -- stop driving
DIY difficulty
hard
Estimated cost
$1,500 - $8,000 (parts and labor)
Diagnose CAN Bus Issues
LAUNCH CRP123X Full System Scanner

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

  • High-voltage battery fault warning
  • Vehicle will not start or move
  • Significant range reduction
  • Battery disconnect warning
  • Multiple EV system warnings

Probable Causes (Ranked by Likelihood)

  • Failed traction battery module A controller Very High
  • High-voltage connection fault High
  • Battery cell failure in module A Moderate
  • CAN bus wiring damage Low

Step-by-Step Diagnostic Procedure

  1. Check high-voltage battery connections

  2. Scan traction battery module A for fault codes

  3. Test CAN bus communication at battery module

  4. Check individual cell voltages in module A

Frequently Asked Questions

Can I drive with U0220?

No. Loss of traction battery communication is a critical failure.

What causes U0220?

Usually a failed battery module controller or high-voltage connection fault.

Is U0220 expensive?

Yes, potentially $1,500 to $8,000 for battery module repairs.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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