EngineLoad Shed System Description and Operation
Load Shed System Description and Operation
Electrical Power Management
The electrical power management is used to monitor and control
the charging system and alert the driver of possible problems
within the charging system. The electrical power management system
makes the most efficient use of the generator output, improves the
battery state-of-charge, extends battery life, and manages system
electrical loads.
The load shed operation is a means of reducing electrical loads
during a low voltage or low battery state-of-charge condition.
The idle boost operation is a means of improving generator
performance during a low voltage or low battery state-of-charge
condition.
Each electrical power management function, either idle boost or
load shed, is discrete. No two functions are active at the same
time. Idle boost is activated in incremental steps, idle boost 1
must be active before idle boost 2 can be active. The criteria used
by the body control module (BCM) to regulate electrical power
management are outlined below:
Function
|
Battery Temperature Calculation
|
Battery Voltage Calculation
|
Amp-Hour Calculation
|
Action Taken
|
Idle Boost 1 Start
|
Less Than -15°C (5°F)
|
Less Than 13 V
|
-
|
First level Idle boost requested
|
Idle Boost 1 Start
|
-
|
-
|
Battery has a net loss greater than 0.6 AH
|
First level Idle boost requested
|
Idle Boost 1 Start
|
-
|
Less Than 10.9 V
|
-
|
First level Idle boost requested
|
Idle Boost 1 End
|
Greater Than -15°C (5°F)
|
Greater Than -12 V
|
Battery has a net loss less than 0.2 AH
|
First level Idle boost request cancelled
|
Load Shed 1 Start
|
-
|
-
|
Battery has a net loss of 4 AH
|
Rear Defrost, Heated Mirrors, Heated Seats cycled OFF for 20% of
their cycle
|
Load Shed 1 Start
|
-
|
Less Than 10.9 V
|
-
|
Rear Defrost, Heated Mirrors, Heated Seats cycled OFF for 20% of
their cycle
|
Load Shed 1 End
|
-
|
Greater Than 12 V
|
Battery has a net loss of less than 2 AH
|
Clear Load Shed 1
|
Idle Boost 2 Start
|
-
|
-
|
Battery has a net loss greater than 1.6 AH
|
Second level Idle boost requested
|
Idle Boost 2 Start
|
-
|
Less Than 10.9 V
|
-
|
Second level Idle boost requested
|
Idle Boost 2 End
|
-
|
Greater Than 12 V
|
Battery has a net loss less than 0.8 AH
|
Second level Idle boost request cancelled
|
Idle Boost 3 Start
|
-
|
-
|
Battery has a net loss of 10.0 AH
|
Third level Idle boost requested
|
Idle Boost 3 Start
|
-
|
Less Than 10.9 V
|
-
|
Third level Idle boost requested
|
Idle Boost 3 End
|
-
|
Greater Than 12 V
|
Battery has a net loss of less than 6.0 AH
|
Third level Idle boost request cancelled
|
Load Shed 2 Start
|
-
|
Less Than 10.9 V
|
Battery has a net loss greater than 12 AH
|
Rear Defrost, Heated Mirrors, Heated Seats cycled OFF for 50% of
their cycle. The BATTERY SAVER ACTIVE message will be displayed on
the DIC
|
Load Shed 2 Start
|
-
|
Less Than 10.9 V
|
-
|
Rear Defrost, Heated Mirrors, Heated Seats cycled OFF for 50% of
their cycle. The BATTERY SAVER ACTIVE message will be displayed on
the DIC
|
Load Shed 2 End
|
-
|
Greater Than 12.6 V
|
Battery has a net loss of less than 10.5 AH
|
Clear Load Shed 2
|
Load Shed 3 Start
|
-
|
Less Than 11.9 V
|
Battery has a net loss greater than 20 AH
|
Rear Defrost, Heated Mirrors, Heated Seats cycled OFF for 100% of
their cycle. The BATTERY SAVER ACTIVE message will be displayed on
the DIC
|
Load Shed 3 End
|
-
|
Greater Than 12.6 V
|
Battery has a net loss of less than 15 AH
|
Clear Load Shed 3
|
|
| |
|
|
11 Engine
