What U0405 means

Invalid Data Received From Cruise Control Module

How to diagnose

  1. Read freeze frame data. When U0405 set, your ECU snapshotted every sensor at that moment. This tells you what the car was doing when the fault triggered — RPM, load, coolant temp, throttle position, fuel trims. Almost always enough info to figure out the cause without further testing.
  2. Check for related codes. If you have U0405 plus other codes, fix the earliest one in the chain first — a single root cause often triggers multiple codes.
  3. Cheap fixes first. For most codes, the order is: inspect connectors + wiring (free), check for vacuum leaks (cheap), replace sensor (moderate), replace mechanical part (expensive). Follow that ladder before dropping money on parts.

Manufacturer-specific descriptions

Different manufacturers use U0405 for slightly different failure modes:

BMWInvalid Data Received From Cruise Control Module
GMInvalid Data Received From Cruise Control Module Invalid Data; Invalid Data Received From Cruise Control Module Message Counter Incorrect; Invalid Data Received From Cruise Control Module Bus Signal Checksum Error
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Related codes

U0400 · U0401 · U0402 · U0403 · U0404 · U0406

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