U0477 moderate

Invalid Data Received From Coolant Pump Module

The U0477 code means the vehicle's onboard diagnostic system has detected: Invalid Data Received From Coolant Pump Module. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$300 - $1,200 (parts and labor)
Diagnose CAN Bus Issues
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Common Symptoms

  • Engine overheating warning
  • Electric coolant pump not running
  • Coolant temperature erratic
  • Reduced power due to overheating

Probable Causes (Ranked by Likelihood)

  • Failed electric coolant pump module Very High
  • Coolant pump motor failure High
  • CAN bus data error Moderate
  • Low coolant level affecting pump Low

Step-by-Step Diagnostic Procedure

  1. Check coolant level

  2. Test coolant pump operation

  3. Scan coolant pump module

  4. Verify CAN bus at pump module

Frequently Asked Questions

Can I drive with U0477?

Only very short distances. Monitor temperature gauge closely and stop if overheating.

What causes U0477?

Usually a failed electric coolant pump or low coolant level.

How much to fix?

Between $300 and $1,200.

Sources

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

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