What causes a U0721 code?

U0721 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 U0721 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with U0721 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

U0721

Network/CAN bus communication code U0721

What it means

Tire Pressure Monitoring System (TPMS) communication fault. The network cannot connect to the receiver that reads tire sensors.

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

Log in Sign up free