U0490 low

Invalid Data Received From Rain/Light Sensor Module

The U0490 code means the vehicle's onboard diagnostic system has detected: Invalid Data Received From Rain/Light Sensor Module. This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
easy
Estimated cost
$100 - $400 (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

  • Auto headlights not responding to light changes
  • Auto wipers too sensitive or not sensitive enough
  • Lights staying on in daylight
  • Tunnel detection not working

Probable Causes (Ranked by Likelihood)

  • Rain/light sensor contaminated Very High
  • Sensor module failure High
  • CAN bus data error Moderate
  • Windshield tint affecting sensor Low

Step-by-Step Diagnostic Procedure

  1. Clean sensor area on windshield

  2. Check sensor after windshield replacement

  3. Scan sensor module for codes

  4. Verify sensor position behind mirror

Frequently Asked Questions

Can I drive with U0490?

Yes. Use manual headlight and wiper controls.

What causes U0490?

Often contamination on the sensor or improper reinstallation after windshield replacement.

How much to fix?

Typically $100 to $400.

Sources

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

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