U0073 fault code: what it means

U0073: Control module communication bus A is off; a module has stopped talking on the CAN network.

Network (communication between modules) · Costly if missed

Usual causes, most likely first

damaged CAN wiring or connector
low battery voltage
faulty module on the network

U0073 by make

Subaru

CAN communication bus off: the main data network between modules has stopped. Many warning lights may come on at once.

Usual causes: weak or failing 12V battery; CAN wiring or connector fault (water, corrosion); a faulty module pulling the bus down

What the repair usually costs

Hybrid 12 V auxiliary battery (Aqua / Prius C / Axio, S34B20R)NZ$330–NZ$510 · A$310–A$500
Hybrid 12 V auxiliary battery (Prius 30 / Prius alpha / CT200h, S46B24R AGM)NZ$390–NZ$690 · A$360–A$590
Hybrid 12 V auxiliary battery (Camry / RAV4 / C-HR / Lexus, S55D23R or LN1-LN2 AGM)NZ$420–NZ$770 · A$390–A$730
EV 12 V battery replace (Nissan Leaf / e-NV200, lead-acid)NZ$200–NZ$340 · A$210–A$380

Not sure what U0073 means on your car? Ask Credov.

Before you clear it

Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.

Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.