Code Definition

U0426 — Invalid Data Received From Vehicle Immobiliser Control Module

System: Network Communication  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About U0426

U0426 is a generic (obd-ii standard) network communication diagnostic trouble code. It belongs to the U-prefix family of codes, which covers inter-module network communication (CAN, LIN, FlexRay, or similar) faults.

Scanning & clearing: Network (U) codes report communication faults between modules. When diagnosing U-codes, checking the vehicle's CAN bus integrity, supply/ground at each module, and reading all modules for related faults is usually the first step.

Because U0426 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The vehicle control modules communicate over the Controller Area Network (CAN) to exchange security and authorisation data. DTC U0426 sets when one or more modules receive CAN messages from the Vehicle Immobiliser Control Module that contain invalid, implausible, or inconsistent data. This indicates the immobiliser module is transmitting data that does not match the expected security states, typically due to internal module faults, an unstable power or ground supply, or CAN integrity issues. Because the immobiliser authorises starting, symptoms can include a no start condition, a flashing secu...

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