Starting System Description And Operation; Starting System - GMC Chevy Colorado 2023 Manual

4-12 12 V Starting and Charging
Idle Boost and Load Shed Without Current Sensor (based on battery voltage) (cont'd)
Function
Idle Boost 3 End
Load Shed 2 Start
Load Shed 2 End
Load Shed 3 Start
Load Shed 3 End
Starting System Description and
Operation
Starter Motor Operation (Without KL9)
The starter motors are non-repairable. They have pole
pieces that are arranged around the armature. Both
solenoid windings are energized. The pull-in winding
circuit is completed to the ground through the starter
motor. The windings work together magnetically to pull
and hold in the plunger. The plunger moves the shift
lever. This action causes the starter drive assembly to
rotate on the armature shaft spline as it engages with
the flywheel ring gear on the engine. Moving at the
same time, the plunger also closes the solenoid switch
contacts in the starter solenoid. Full battery voltage is
applied directly to the starter motor and it cranks the
engine.
As soon as the solenoid switch contacts close, current
stops flowing thorough the pull-in winding because
battery voltage is applied to both ends of the windings.
The hold-in winding remains energized. Its magnetic
field is strong enough to hold the plunger, shift lever,
starter drive assembly, and solenoid switch contacts in
place to continue cranking the engine. When the
engine starts, pinion overrun protects the armature from
excessive speed until the switch is opened.
When the crank signal is removed, the starter relay
opens and battery voltage is removed from the starter
solenoid S terminal. Current flows from the motor
contacts through both windings to the ground at the end
of the hold-in winding. However, the direction of the
current flow through the pull-in winding is now opposite
the direction of the current flow when the winding was
first energized.
The magnetic fields of the pull-in and hold-in windings
now oppose one another. This action of the windings,
along with the help of the return spring, causes the
starter drive assembly to disengage and the solenoid
switch contacts to open simultaneously. As soon as the
contacts open, the starter circuit is turned off.
Battery Temperature
Calculation Battery Voltage Calculation
Greater Than 12.3 V
Less Than 12.1 V
Greater Than 12.2 V
Less Than 11.9 V
Greater Than 12.0 V
Enhanced Starter Motor
Operation (KL9)
The Engine Stop/Start system in GM vehicles
automatically turns off the engine when the vehicle
comes to a stop under certain driving conditions, and
can quickly restart the engine in about 0.3 seconds
when commanded to do so.
In order to smoothly restart the engine as quickly as
possible while managing the greater number of engine
starts, the Stop/Start system uses an enhanced starter
motor that operates differently from a conventional
starter motor. It has a high performance electric motor
and a stronger pinion engagement mechanism than a
conventional starter. It also has independent control of
the pinion and motor.
The enhanced starter motor continues using the typical
pinion engagement mechanism with a starter solenoid
that drives the pinion gear to engage or disengage the
flywheel of the engine. When engaged, the starter
motor can rotate the engine flywheel and, in turn, the
crankshaft.
On the enhanced starter of a Stop/Start system the
operation is done in two separate functions inside the
solenoid, Starter Motor and Pinion Actuator. Each
function controlled individually by the ECM. There are
two separate relays to control the two separate parts of
the enhanced solenoid:
KR27 Starter Motor Relay
KR27C Starter Pinion Actuator Relay
The two individually-controlled relays allow for smooth
engagement of the pinion gear into the flywheel with
minimum noise and wear.
When the vehicle is coming to a stop, just before the
engine stops rotating (at approximately 50 RPM) during
stop/start operation, the ECM energizes the Starter
Pinion Solenoid Actuator Relay to easily push the
pinion gear into the flywheel gear without gear clash.
(Fig. 8) When the engine stops rotating during Stop/
Start operation (Auto Stop mode), the starter pinion
gear is fully engaged, ready for the starter motor to
become energized to quickly start the engine again.
Action Taken
Third level Idle boost request
cancelled
Rear Defrost, Heated Mirrors,
Heated Seats, HVAC cycled
OFF for 50% of their cycle.
The BATTERY SAVER
ACTIVE message will be
displayed on the DIC
Clear Load Shed 2
Rear Defrost, Heated Mirrors,
Heated Seats, HVAC cycled
OFF for 100% of their cycle.
The BATTERY SAVER
ACTIVE message will be
displayed on the DIC
Clear Load Shed 3
2023 - Colorado Electrical Body Builder Manual