OBD Guide

U0073

Control Module Communication Bus A Off

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$6–56 (est.)

Symptoms

  • Check Engine Light Is On
  • Disconnection or incorrect operation of various vehicle systems
  • Problems starting the engine
  • Dashboard malfunctions
  • Lost connection with diagnostic equipment

Causes

  • Broken CAN bus wires
  • Short circuit in CAN circuit
  • Corrosion or poor contact in connectors
  • Failure of one of the modules on the bus
  • Damage to CAN bus terminators

How to Fix

  1. Check the integrity of the CAN bus wires
  2. Check connections and connectors for corrosion
  3. Diagnose modules on the CAN bus one by one
  4. Check the resistance of the bus terminators
  5. Replace damaged wires or connectors

Related codes

Error U0073 by Vehicle Brand