Multifunction steering wheel w LIN bus

LIN/CAN bus compact training system for controlling a multifunction steering wheel with fault switches

The system consists of two networked original control units and a simulated control unit:

• Steering column electronics
• Control unit for multifunction steering wheel
• Vehicle electrical system control unit

As a “subbus” to the CAN data bus, the LIN (= Local Interconnect Network) bus is a single-wire bus that provides sensor data or triggers actuator events at the request of the CAN bus master.

There are essentially two LIN bus controls available:

1. Control of the brightness of the button illumination and
2. Control of the steering wheel temperature.

The brightness control for the button illumination reads the desired value via the vehicle electrical system control unit, transmits it via the CAN bus to the steering column electronics and on via the LIN bus and cascaded PWM to the button panels.

The temperature control has a constant but changeable setpoint. If the steering wheel heating is switched on, it heats until the setpoint temperature is reached (two-point control).

MobileCASSY (524005W2) is used to record the measured values at the 4 mm measuring sockets and evaluate the data telegrams. The data telegrams can be recorded and interpreted using an oscilloscope. For further protocol analysis, the CAN bus multi adapter (773961) or the LIN bus PC adapter USB (7395881) can be used.

The lockable fault switch box can be used to activate 12 CAN or LIN faults, such as:

• Ground fault
• Positive fault
• Fault between CAN H and CAN L
• Transition resistances
• Interruptions

The training system includes:

• CAN bus-compatible vehicle electrical system control unit simulation
• CAN and LIN bus-compatible steering column electronics
• LIN bus-compatible control unit for multifunction steering wheel
• LIN bus-compatible keypad on the right
• PWM-controlled keypad on the left
• Fault switch box (CAN and LIN faults)

The system is capable of self-diagnosis via the diagnostic interface. Important diagnostic options can be run through using a corresponding diagnostic tester, the Automotive Diagnostic Adapter CAN+USB (7379803).