The gas warning system in the Hydrogen 7 vehicle consists of five H2 sensors that communicate across the CAN bus (H2 CAN) with the CESG. These sensors determine the H2 concentration at their respective installation locations (occupant area, engine compartment, luggage compartment, fill coupling, secondary system capsule) and indicate this by means of CAN messages. The H2 sensors are also able to check range boundaries of H2 concentrations and to wake the CESG from the semi-sleep state if these boundaries are exceeded. (These range boundaries are sent by the CESG to each sensor so that it can be wakened in the event of changes in H2 alarm states.)
In the event of an increased H2 concentration, the CESG triggers the corresponding reactions (for example, changeover from hydrogen mode to petrol mode, closing the valves, messages in the instrument cluster).
In addition, the four LEDs in the four car doors are activated in the event of a gas alarm (H2 alarm). These LEDs flash in the event of a gas alarm!
The H2 sensors are monitored for diagnosis; the H2 warning LEDs are not monitored for diagnosis.
The Clean Energy control unit (CESG) determines the H2 concentration values of all H2 sensors via the CAN bus and sets the range boundaries for each sensor. The values for the states currently detected at each of the five measuring points are sent by the CESG to the H2 sensors. The following alarm states exist:
Within the framework of the test module for these components, the following faults are covered: