DTC P0440 Mini

Description

Key on or engine running; system voltage supplied to the module is in the normal operating voltage range, vehicle power mode requires serial data communication to occur, and the ECM did no detect any valid messages on the Class 2 circuit, or the voltage condition detected on the Class 2 circuit was low for 3 seconds. Modules connected to the Class 2 circuit check for data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. Each module transmits Node Alive messages on the Class 2 data circuit once every 2 seconds. When the module detects a low voltage condition on the Class 2 serial data circuit for approximately 3 seconds, it sets U1300 or U1305 if it cannot identify the problem. Note: This code is set by loss of communication. Look in All of the modules for this trouble code - the one without it has a problem