Can Bus Terminal Resistance, Checking: Function

The Engine Control Module (ECM) -J623- communicates with other CAN-Bus capable control modules.

The control modules are connected by two data bus wires referred to as CAN High and CAN Low. The CAN bus allows the exchange of information (messages) between the connected modules. Messages that are missing data on the CAN bus are recognized as a malfunction by the control module connected to the CAN bus that received the invalid data.

Trouble-free operation of the CAN Bus requires that it have a Terminal Resistance. This central Terminal Resistance is located in the Engine Control Module (ECM) -J623-.