RAM 1500 Truck 2WD V8-5.7L VIN 2 (2006)
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The PCM monitors the O2S sensor input and adjusts air-fuel ratio by varying injector pulse width. It also adjusts engine idle speed through the idle
air control (IAC) motor.
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The PCM adjusts ignition timing by increasing and decreasing spark advance.
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The PCM operates the A/C compressor clutch through the A/C compressor clutch relay. This is done if A/C has been selected by the vehicle
operator and specified pressures are met at the high and low-pressure A/C switches. Refer to Heating and Air Conditioning.
CRUISE MODE
When the engine is at operating temperature, this is a Closed Loop mode. At cruising 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)
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Battery voltage
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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 sensor (TPS)
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Camshaft position sensor signal
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Park/neutral switch (gear indicator signal-auto. trans. only)
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Oxygen (O2S) sensors
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 adjust the injector pulse width by turning the ground
circuit to each individual injector on and off.
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The PCM monitors the O2S sensor input and adjusts air-fuel ratio. It also adjusts engine idle speed through the idle air control (IAC) motor.
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The PCM adjusts ignition timing by turning the ground path to the coil(s) on and off.
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The PCM operates the A/C compressor clutch through the clutch relay. This happens if A/C has been selected by the vehicle operator and
requested by the A/C thermostat.
ACCELERATION MODE
This is an Open Loop mode. The PCM recognizes an abrupt increase in throttle position or MAP pressure as a demand for increased engine output and
vehicle acceleration. The PCM increases injector pulse width in response to increased throttle opening.
DECELERATION MODE
When the engine is at operating temperature, this is an Open Loop mode. During hard deceleration, the PCM receives the following inputs.
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Air conditioning select signal (if equipped)
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Air conditioning request signal (if equipped)
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Battery voltage
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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 sensor (TPS)
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Camshaft position sensor signal
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Park/neutral switch (gear indicator signal-auto. trans. only)
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Vehicle speed
If the vehicle is under hard deceleration with the proper rpm and closed throttle conditions, the PCM will ignore the oxygen sensor input signal. The
PCM will enter a fuel cut-off strategy in which it will not supply a ground to the injectors. If a hard deceleration does not exist, the PCM will determine
the proper injector pulse width and continue injection.
Based on the above inputs, the PCM will adjust engine idle speed through the idle air control (IAC) motor.
The PCM adjusts ignition timing by turning the ground path to the coil on and off.
WIDE OPEN THROTTLE MODE
This is an Open Loop mode. During wide open throttle operation, the PCM receives the following inputs.
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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 sensor (TPS)
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Camshaft position sensor signal
During wide open throttle conditions, 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
