Suzuki 2007 XL7, Service Manual

Page: 3059 / 3159

Cruise Control System: 10A-1
Cruise Control System
General Description
Cruise Control Description and Operation
Cruise control is a speed control system that maintains a
desired vehicle speed under normal driving conditions at
vehicle speeds above 40 km/h (25 mph). Steep grades
may cause variations in the selected vehicle speeds.
The following are the main components of the cruise
control system:
• The accelerator pedal
• The brake pedal position (BPP) sensor
• The body control module (BCM)
• The engine control module (ECM)
• The on/off switch
• The cancel switch
• The + RES switch, equivalent to resume/accel switch
• The - SET switch, equivalent to set/coast switch
• The throttle actuator control (TAC) motor
• The vehicle speed sensor
The body control module (BCM) monitors the signal
circuit of the cruise control switches, which are located
on the steering wheel. The BCM relays the cruise control
switch status to the engine control module (ECM) via the
GMLAN serial data circuit. The ECM uses the status of
the cruise control switch to determine when to capture
and maintain the vehicle speed. The ECM monitors the
vehicle speed signal circuit in order to determine the
desired vehicle speed. The ECM uses the TAC motor in
order to maintain the vehicle speed. For further
information on the TAC system, refer to “Throttle
Actuator Control (TAC) System Description: ”.
Voltage is supplied to the cruise control switch via the
steering wheel control switch reference voltage circuit
supplied by the BCM. The cruise control function
switches are arranged in a resistive ladder design, with
each cruise control function switch having a different
resistance value. The BCM detects a specific voltage
value that is associated with the cruise control function
switch being activated. When the normally open cruise
control on/off switch is turned ON, the switch closes and
the BCM supplies a ground to the cruise control switch
ON indicator circuit as it becomes illuminated. The BCM
sends a GMLAN serial data message to the ECM
indicating that the on/off switch is active. Similarly, when
the normally open + RES switch or the normally open
−
SET switch are pressed, the switch closes and the BCM
detects the predetermined voltage signal on the cruise
control resume/accel and set/coast switch signal circuit.
The BCM sends a GMLAN serial data message to the
ECM indicating that the + RES switch or the
−
SET
switch is active. The + RES switch or the
−
SET switch
will remain inactive when the BCM has not received the
predetermined voltage signal from the on/off switch.
Cruise Control Engaged
The cruise control system will engage and adjust vehicle
speeds, based on the activation of the following cruise
control switches, which are located on the steering
wheel:
• On/off
• + RES
•
−
SET
To engage the cruise control system, ensure that the
vehicle speed is above 40.2 km/h (25 mph), turn the
cruise On/Off switch ON and momentarily press the
−
SET switch. The ECM will engage the cruise control
system and record the vehicle speed. The ECM sends a
GMLAN serial data message to the instrument panel
cluster (IPC) in order to illuminate the Cruise Engaged
indicator in the IPC.
Pressing the accelerator pedal while the cruise control
system is engaged, allows the driver to override the
cruise control system in order to accelerate the vehicle
beyond the current set vehicle speed. When the
accelerator pedal is released, the vehicle will decelerate
and resume the current set vehicle speed. The driver
can also override the current set vehicle speed via the
−
SET switch and the + RES switch. When the cruise
control system is engaged, pressing and holding the
−
SET switch will allow the vehicle to decelerate from the
current set vehicle speed without deactivating the cruise
control system. When the
−
SET switch is released, the
ECM will record the vehicle speed and maintain the
vehicle speed as the new set vehicle speed. When the
cruise control system is engaged, momentarily pressing
the
−
SET switch will allow the vehicle to decelerate at
1.6 km/h (1 mph) increments for each time that the
−
SET is momentarily pressed, with a minimum vehicle
speed of 37 km/h (23 mph).
Pressing and holding the + RES switch, when the cruise
control system is engaged, will allow the vehicle to
accelerate to a greater vehicle speed than the current
set vehicle speed. When the + RES switch is released,
the ECM will record the vehicle speed and maintain the
vehicle speed as the new set vehicle speed. When the
cruise control system is engaged, momentarily pressing
the + RES switch will allow the vehicle to accelerate at
1.6 km/h (1 mph) increments for each time that the +
RES switch is momentarily pressed, with the maximum
acceleration total of 16 km/h (10 mph) over the current
set vehicle speed. Momentarily activating the + RES
switch will recall the previous vehicle speed, after the
cruise control system is disengaged by pressing the
brake pedal or by activating the CANCEL switch.