Warning Lamp

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.

CAN System

The following CAN messages are used for control of the cruise control system: l Cruise control status, from the ECM. To advise the interface ECU if the ECM cruise control mode is active or inactive. Also used by the instrument pack to operate the cruise control warning lamp. l Road speed, produced by the ABS modulator from ABS sensor inputs. Used by the ECM for monitoring vehicle speed. l Accelerator pedal position, from the ECM. Used by the EAT ECU for gear change control. l Gear lever position, from the EAT ECU. Used by the ECM to ensure the vehicle is in drive for cruise control operation.

Brake Pedal Sensor

Outputs from the brake pedal sensor are supplied to the ECM to enable the system to detect when the brakes are applied. The brake pedal sensor is a Hall effect sensor that produces two outputs. Both outputs should be 0 to 2 volts while the brake pedal is released. When the brake pedal is pressed, the Brake Lamp Switch (BLS) output increases to between 6 and battery volts, the Brake Test Switch (BTS) output increases to between 10 and battery volts.

ECM

The ECM incorporates a software module and associated components to enable cruise control operation by direct control of the electric throttle. In addition to controlling the throttle, the software module monitors hardwired and CAN bus inputs to the ECM and prevents or suspends cruise control operation when the vehicle is not in the correct driving configuration.