Controller Area Network System

Controller Area Network System

The Controller area network (CAN) system is monitored by the ECM for the following conditions.

Invalid signal Error
The ECM is continually receiving data from a number of other control modules via the CAN system. If one of these control module identifies a problem within its own system that cause it to be unable to transmit valid data, it will a store DTC locally and transmit an error marker ( a specific default value of the data that indicates an error ) on to the CAN system. When the ECM identifies an error marker from another control module, it also logs a failure.

Vehicle Options Error
The car configuration file is stored in both the instrument pack and the ECM. The instrument pack transmits car configuration data to the other control modules in the vehicle using the CAN system. If the ECM recognizes that the data transmitted by the instrument pack doe not match the data stored in its own EEPROM then a failure is registered.

VIN Mismatch
The Vehicle Identification Number (VIN) is stored in several of the vehicles control modules. The number stored in the instrument pack is transmitted using the CAN system when the ignition is switched on. If the number transmitted by the instrument pack does not match the number stored in the ECMs EEPROM then the ECM registers a failure. If the failure is registered on 2 drive cycles, the MIL is illuminated.

Loss of Communications
All of the control modules on the CAN system transmit data continually. If messages from one or more of the control modules are not seen by the ECM within a predefined time, it will register a loss of communications failure.











If the above table does not include details of the following enabling conditions: - IAT, ECT, vehicle speed range, and time after engine start-up then the state of these parameters has no influence upon the execution of the monitor.