U0409 moderate

Invalid Data Received From Park Brake Control Module

The U0409 code means the vehicle's onboard diagnostic system has detected: Invalid Data Received From Park Brake Control Module. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$200 - $800 (parts and labor)
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Common Symptoms

  • Electronic parking brake warning light on
  • Parking brake applies or releases unexpectedly
  • Parking brake status indicator incorrect
  • Hill hold assist malfunction
  • Auto hold feature not working correctly

Probable Causes (Ranked by Likelihood)

  • Park brake module sending invalid position data Very High
  • Park brake actuator motor position sensor fault High
  • Wiring issue to park brake actuator Moderate
  • Park brake switch sending incorrect signals Low

Step-by-Step Diagnostic Procedure

  1. Check park brake actuator motor operation with a scan tool

  2. Monitor park brake position sensor data for invalid readings

  3. Inspect wiring to the rear brake calipers with electronic actuators

  4. Verify the park brake switch on the console is functioning

  5. Check for related brake system codes

Frequently Asked Questions

Can I drive with code U0409?

Drive short distances only. The electronic parking brake may behave unpredictably. Park on flat surfaces and use wheel chocks until repaired.

What causes U0409?

Typically a failing park brake actuator position sensor or the park brake module itself. These components are at the rear brakes and exposed to the elements.

Is U0409 expensive to fix?

Expect $200 to $800. Park brake actuator replacement at the calipers is the most common fix. Module replacement with programming costs more.

Sources

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

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