GMC Chevy Colorado 2023 Manual page 100

4-14 12 V Starting and Charging
When the Stop/Start System has shut down the engine,
and the ambient temperature is below 15°C (59°F), the
ECM will activate the Stop/Start auxiliary relay which
controls the electric engine coolant pump motor to
continually circulate the engine coolant through the
engine while the engine is off. This is to ensure the
engine and passenger compartment temperature is
maintained while off. Once the Stop/Start System has
restarted the engine, the ECM will turn off the electric
coolant pump motor, thus allowing the engines internal
coolant pump to circulate the engine coolant. The Stop/
Start System is automatically activated each time the
ignition switch is turned on.
Through the climate control system, the vehicle can be
cycled between off, comfort, and eco air conditioning
modes (if equipped). In comfort mode, the priority for
Stop/Start operation is on customer comfort.
Depending on ambient temp, humidity, cabin
temperature and cabin temperature setpoint, the least
amount of autostops occur in this mode. In eco mode,
the priority is on fuel economy. There are more frequent
autostops with some sacrificing of cabin temperature
control. With the HVAC turned off, the maximum
autostops occur since there will be no A/C compressor
requests.
Autostop Enable Ambient and Engine Coolant Temperature Table
Ambient Temperature
10°C (14°F)
0°C (32°F)
6°C (43°F)
12°C (54°F)
20°C (68°F)
30°C (86°F)
Autostart Criteria
The ECM will send an Autostart state message to the
BCM. If all of the following conditions are true the ECM
and BCM will restart the vehicle.
Driver Enabled Conditions that will engage Autostart:
Driver removes pressure from the brake or
depresses the accelerator pedal while the vehicle
is in the forward Drive gear
System Enabled Conditions that will engage Autostart
Note: If one or more of the following conditions occur,
the system will force the engine to restart.
Brake booster vacuum is less than 40 kPa (6 PSI)
A/C compressor request from HVAC (A/C or
Defrost modes)
Battery voltage less than 11 V,
Autostop Criteria
The ECM will send an Autostop state message to the
body control module (BCM) and shut down the engine
when all of the following criteria is met. The BCM will
transmit the Autostop state message to the instrument
cluster which will display the Autostop indicator in the
tachometer display.
Initial minimum vehicle speed during drive cycle
must be 19 km/h (12 MPH) or greater. Subsequent
autostop minimum speed may vary from
2-10 km/h (1-6 MPH), depending on vehicle
Ambient and engine coolant temperature
correlation meets specified values.
Ambient and transmission fluid temperature
correlation meets specified values.
Hood switch status is closed
Driver door status is closed
Driver seat belt status is buckled
Brake booster vacuum is greater than
45 kPa (7 PSI)
Transmission gear selector is in the Drive position
Vehicle speed is less than 5 km/h (3 MPH)
Engine speed is below 1,500 RPM
Engine coolant temperature is less than 120°
C (248°F)
Ambient temperature is greater than 10°C (14°F)
No A/C compressor request from HVAC (A/C or
Defrost modes)
Battery voltage greater than 12 V
Battery state of charge greater than 75% (changes
with state of health)
inimum Coolant Temperature
60°C (140°F)
50°C (122°F)
40°C (104°F)
30°C (86°F)
18°C (64°F)
18°C (64°F)
Battery state of charge is less than 73% (changes
with state of health)
Driver door status changes to open and driver seat
belt status changes to unbuckled (not applicable
to vehicles in North America)
Hood switch status changes to open
Autostop time exceeded 2 min
If the crank time exceeds 2 s, a manual ignition switch
restart will be necessary.
System Components
Engine Control Module (ECM)
The ECM monitors the inputs from the Engine Coolant
Temperature (ECT) sensor, Vehicle Speed
Sensor (VSS), Battery Sensor Module, hood ajar
switch, brake booster vacuum sensor, and engine
Autostop Enable
Yes
Yes
Yes
Yes
Yes
Yes
2023 - Colorado Electrical Body Builder Manual