U0304 low

Software Incompatibility With Cruise Control Module

The U0304 code means the vehicle's onboard diagnostic system has detected: Software Incompatibility With Cruise Control Module. This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
moderate
Estimated cost
$100 - $400 (parts and labor)
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Common Symptoms

  • Cruise control not engaging
  • Adaptive cruise control unavailable
  • Cruise control warning light on
  • Speed limiter function not working
  • Steering wheel cruise buttons unresponsive

Probable Causes (Ranked by Likelihood)

  • Cruise control module software outdated after ECM update Very High
  • Incompatible software between cruise and braking modules High
  • Failed cruise control module software update Moderate
  • Aftermarket cruise control system conflicting Low

Step-by-Step Diagnostic Procedure

  1. Check cruise control module software version

  2. Verify brake switch signal reaches the cruise control module

  3. Look for manufacturer TSBs about cruise control software updates

  4. Reflash the cruise control module to the latest calibration

  5. Check for related ADAS or braking system codes

Frequently Asked Questions

Can I drive with code U0304?

Yes, safe to drive. Only the cruise control function is unavailable. All other driving systems work normally.

What causes U0304?

Typically caused by a software version mismatch after an ECM or body module update. The cruise control module needs a matching software update.

Is U0304 expensive to fix?

Usually $100 to $400. A software reflash at the dealer is the most common and least expensive fix.

Sources

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

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