Freelander System Description and Operation
ENGINE MANAGEMENT SYSTEM - SIEMENS
DESCRIPTION AND OPERATION 18-4-47
Interface ECU Harness Connector (C1959)
MFL Messages
The interface ECU outputs one of three MFL messages, RESUME, SET or OFF, on a serial link to the ECM. The
power feed from the main relay to the interface ECU drives the MFL messages. While the master switch is selected
off, only the OFF MFL message can be transmitted. When the master switch is selected on, the power feed from the
switch enables the interface ECU to send either the SET or RESUME MFL messages, depending on the inputs from
the steering wheel switches and the cruise control status message from the CAN bus. When the master switch is first
switched on, the output of the RESUME message is automatically inhibited until after the first engagement of cruise
control.
Cruise Engaged Signal
When cruise control is engaged, the interface ECU outputs battery voltage on a connection to the EAT ECU to provide
a cruise control engaged signal. The EAT ECU uses the signal to switch between normal and cruise control modes
of operation.
Warning Lamp
The warning lamp indicates the status of the cruise control system. Located in the instrument pack, the warning lamp
illuminates when cruise control is engaged, and consists of an amber CRUISE legend.
Pin No.
Description
Input/Output
1
System earth
-
2
MFL signal
Output
3
SET+ switch
Input
4
RES switch
Input
5
CAN bus low (L line)
Input/Output
6
CAN bus high (K line)
Input/Output
7
Cruise control master switch
Input
8
Ignition power supply
Input
9
Cruise control engaged signal
Output
10 to 12
Not used
-