Magnum V8-5.7L (2008)
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Intake manifold air temperature sensor input is monitored.
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Throttle position sensors (TPS) and pedal value sensors are monitored.
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The auto shutdown (ASD) relay is energized by the PCM for approximately three seconds.
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The fuel pump is energized through the fuel pump relay by the PCM. The fuel pump will operate for approximately three seconds unless the
engine is operating or the starter motor is engaged.
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The O2S sensor heater element is energized via the O2S heater drivers (solid state devices) internal to the PCM. These drivers provide a PWM
0-12V signal to heat the O2S heater elements to optimize the O2S sensor signal output. The O2S sensor input is not used by the PCM to calibrate
air-fuel ratio during this mode of operation.
ENGINE START-UP MODE
This is an Open Loop mode. The following actions occur when the starter motor is engaged.
The PCM receives inputs from:
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Direct Battery voltage
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Pedal Value Sensors (PVS)
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Engine coolant temperature sensor
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Crankshaft position sensor
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Intake manifold air temperature sensor
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Manifold absolute pressure (MAP) sensor
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Throttle position sensors (TPS)
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Camshaft position sensor signal
The PCM monitors the crankshaft position sensor. If the PCM does not receive a crankshaft position sensor signal within approximately 3 seconds of
cranking the engine, it will shut down the fuel injection system.
The fuel pump is activated by the PCM through the fuel pump relay located in the IPM.
Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width by
actuating ground circuit to each individual injector on and off.
The PCM determines the proper ignition timing according to input received from the crankshaft position sensor.
ENGINE WARM-UP MODE
This is an Open Loop mode. During engine warm-up, the PCM receives inputs from:
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Direct Battery voltage
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Crankshaft position sensor
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Engine coolant temperature sensor
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Intake manifold air temperature sensor
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Manifold absolute pressure (MAP) sensor
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Throttle position sensors (TPS)
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Camshaft position sensor signal
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Park/neutral switch (gear indicator signal)
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Pedal Value Sensors (PVS)
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Air conditioning select signal (if equipped)
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Air conditioning request signal (if equipped)
Based on these inputs the following occurs:
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Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width
by turning the ground circuit to each individual injector on and off.
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The PCM adjusts engine idle speed through the electronic throttle control (ETC) motor and adjusts ignition timing accordingly.
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The PCM operates the A/C compressor clutch through the clutch relay. This is done if A/C has been selected by the vehicle operator and requested
by the A/C thermostat.
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When engine has reached operating temperature, the PCM will begin monitoring O2S sensor to control the air/fuel ratio. The system will then
leave the warm-up mode and go into closed loop operation.
IDLE MODE
When the engine is at operating temperature, this is a Closed Loop mode. At idle speed, the PCM receives inputs from:
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Air conditioning select signal (if equipped)
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Air conditioning request signal (if equipped)
