U0491 low

Invalid Data Received From Compass Module

The U0491 code means the vehicle's onboard diagnostic system has detected: Invalid Data Received From Compass Module. This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
easy
Estimated cost
$50 - $300 (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

  • Compass showing wrong direction
  • Compass reading stuck
  • Compass not calibrating
  • Compass display blank

Probable Causes (Ranked by Likelihood)

  • Compass module failure Very High
  • Magnetic interference near sensor High
  • CAN bus data error Moderate
  • Compass calibration lost Low

Step-by-Step Diagnostic Procedure

  1. Recalibrate compass by driving in circles

  2. Check for magnetic interference

  3. Scan compass module

  4. Reset module and recalibrate

Frequently Asked Questions

Can I drive with U0491?

Yes. Use your phone for navigation direction.

What causes U0491?

Often magnetic interference from aftermarket accessories or a compass needing recalibration.

How much to fix?

Typically $50 to $300. Recalibration is often free.

Sources

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

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