SRX AWD V8-4.6L VIN A (2004)
load management will execute in the load management control algorithm when there is a high discharge condition:
1. The first action requests a vehicle idle speed increase to the engine control module (ECM) in order to raise alternator output.
2. The second action requests a greater vehicle idle speed increase to the ECM in order to raise alternator output.
3. The third action, begins to shed vehicle loads in an attempt to remedy the heavy discharge condition.
4. The fourth action requests another vehicle idle speed increase to the ECM in order to raise further the alternator output.
5. The fifth action, begins to shed further vehicle loads in an attempt to remedy the heavy discharge condition.
6. If the above five corrective actions fail, the sixth action of power management further sheds loads in a final attempt to remedy the high discharge
condition.
Loads subject to reduction include the following:
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The A/C clutch
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The heated mirrors
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The heated seats
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The rear defog
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The HVAC blowers
The power mode master (PMM) calculates the battery temperature, voltage and charging rate at all times while the engine is running. The PMM
calculates the battery temperature by factoring in:
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the current intake manifold air temperature compared to the last temperature recorded when the ignition switch was turned OFF
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the current battery voltage compared to the last battery voltage recorded when the ignition switch was turned OFF
-
the length of time since the last battery temperature calculation
If the battery temperature is below set limits, the PMM institutes steps to control the load.
The PMM calculates the voltage of the battery by making constant measurements and using the measurements to calculate the true battery voltage. It
the PMM detects a low voltage, the PMM institutes steps to control the load.
The PMM calculates the discharge rate, or draw, on the battery by making constant measurements and using the measurements to calculate the
discharge rate in amp/hours. If the PMM detects a high current draw from the battery, the PMM institutes steps to control the load.
The PMM will either request an increase in the engine idle speed to the ECM or the PMM will cycle or turn off loads, called the load-shed function, in
order to preserve the vehicle electrical system operation. The criteria used by the PMM to regulate this electrical load management are outlined.
