U0406 moderate

Invalid Data Received From Fuel Injector Control Module

The U0406 code means the vehicle's onboard diagnostic system has detected: Invalid Data Received From Fuel Injector Control Module. This is a moderate severity code.

My Garage →
Keep driving?
Yes, but fix soon
DIY difficulty
hard
Estimated cost
Varies — depends on the specific component this manufacturer-specific code points to on your vehicle. Diagnose before buying parts.
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.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

  • Check Engine or a related warning light on
  • Exact symptoms depend on the specific system this code covers for your make
  • A make-specific scan reveals which subsystem and circuit is involved

Probable Causes (Ranked by Likelihood)

  • A fault in the specific component or circuit this code monitors (the exact part varies by manufacturer) High
  • Damaged wiring, a corroded connector, or a poor ground in that circuit Moderate
  • A related sensor or control module reporting or causing the fault Moderate

Step-by-Step Diagnostic Procedure

  1. Confirm your exact make, model, and year first — U0406 is manufacturer-specific and can mean different things across brands.

  2. Read U0406 with an enhanced/make-specific scan tool and check your manufacturer's official service information for the precise definition and procedure.

  3. Inspect the wiring, connectors, and grounds for the indicated circuit before replacing any part.

Frequently Asked Questions

Does U0406 mean the same thing on every vehicle?

No. U0406 is a manufacturer-specific diagnostic trouble code, so its exact meaning varies by make, model, and year. Always confirm it against your vehicle manufacturer's service information before diagnosing or replacing parts.

What does U0406 most likely indicate?

Invalid Data Received From Fuel Injector Control Module. Treat this as a general guide and verify the specifics for your vehicle.

Sources

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

Explore More

Search codes Vehicle-specific fixes Guides By make

Was this helpful?

Share carcodefinder.com with a friend who needs to decode their check engine light.

Browse by symptom → Read repair guides → Fixes by vehicle →