MoTeC MDC - Manual (Page 7)

MoTeC MDC 5 Functionality
Note: if the MDC is powered up with the steering at full lock it will read +/-360deg when the wheels are straight.
This is a characteristic of the steering sensor which will be automatically corrected when the vehicle starts moving,
through analysis of steering angle, vehicle speed and lateral G force.
Hydraulic Pressure Pump Control
The MDC reads the hydraulic pressure sensor and controls the pump to maintain hydraulic pressure for the ACD.
The MDC implements the following strategies to protect the pump from being overrun and burnt out:
• If the pressure sensor is faulty or missing then the pump is turned off and remains off until the pressure
sensor reads a valid reading.
• If the pump has run for more than 20 seconds without achieving at least the low pressure threshold, the
pump is turned off for 20 seconds and a fault is indicated by a flashing mode indicator light.
• The pump will never run when the 0% lock mode has been selected
Hydraulic Pressure Pump Priming Mode
The hydraulic pressure pump priming mode allows the pump to be run manually by a technician during priming of
the hydraulic system.
To enter the pump priming mode, the ACD button should be pressed while turning on the ignition, and then remain
held pressed for five seconds. The SNOW and TARMAC lights on the dash will toggle when the priming mode is
active.
When priming mode is active, the diff lock is set at 50% and the hydraulic pump is run while the throttle pedal is
pressed down.
To exit the pump priming mode, the ignition should be turned off.
NOTE: The pump prime mode should be used with care by experienced technicians only. The MDC does NOT
restrict pump run time or hydraulic pressure during pump prime mode.
Communications
User CAN Bus
The MDC can communicate with a MoTeC ADL or a PC over the 1Mbit/sec User CAN bus. The MDC is connected
to a CAN bus using a separate communications connector. This cable also provides the power required if the
MoTeC CAN cable is used to interface with a PC.
The MDC transmits CAN messages at 50Hz containing information about all input and output functions, such as
speed readings, diff currents etc.
The MDC transmits CAN messages at 25Hz containing diagnostic information such as fault flags, firmware
versions etc.
To configure an ADL to receive MDC messages, use the ‘MDC’ and ‘MDC Diagnostics’ communications templates
included with Dash Manager.
The transmission of CAN messages can be disabled. This feature may be used to prevent reverse engineering of
user control modes.
The CAN bus is also used for communication with a PC for configuration and upgrading firmware using the
MoTeC UTC (USB To CAN) adaptor or the MoTeC CAN cable.
See Appendix C – CAN Wiring Practices for recommended CAN wiring practices
ECU Comms Bus
The MDC can communicate with a MoTeC EVO89 or EVO48 OEM ECU over a half-duplex RS232 link using the
factory wiring loom.