What causes a U0426 code?

U0426 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a U0426 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with U0426 active.

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

Log in Sign up

OBD-II

U0426

Network/CAN bus communication code U0426

What it means

Invalid data received from Vehicle Immobilizer Control Module. The security handshake for starting the vehicle has failed.

Sign in to view symptoms, probable causes, diagnostic steps, severity, and related codes

Log in Sign up free