G 2500 3/4 Ton Van V8-350 5.7L VIN K TBI (1995)
EGR Valve Connector
DESCRIPTION
The linear EGR valve is operated exclusively by control module command. The control module monitors various engine parameters:
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Throttle Position (TP) sensor.
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Manifold Absolute Pressure (MAP).
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Engine Coolant Temperature (ECT) sensor.
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Pintle position sensor.
Output messages are then sent to the EGR system indicating the proper amount of exhaust gas recirculation necessary to lower combustion
temperatures. This electronic metering of exhaust gas is ten times faster than vacuum-operated models and offers improved diagnostic capabilities
as well.
CONNECTOR
Positioned at the top of the linear EGR assembly are 5 terminals:
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"A" is the pulse width modulated negative signal from the control module.
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"E" is the positive from ignition.
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"B", "C" and "D" are terminals from the control module for the integral pintle position sensor.
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"B" is sensor ground.
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"C" is sensor output.
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"D" is +5 volts supply.
OPERATION
The solenoid (bobbin and coil) assembly is energized by 12 volt current which enters the valve through an electrical connector (terminal "E"), then
flows through the solenoid assembly to the control module and creates an electromagnetic field. This field causes the armature assembly to be
pulled upward, lifting the pintle a variable amount off the base.
The exhaust gas then flows from the exhaust manifold (through the orifice) to the intake manifold. The height of the pintle is read by the pintle
position sensor, and the control module closes the loop on desired position versus actual position read, changing the pulse width modulated
command to the solenoid accordingly, until the actual pintle position equals the desired pintle position.
This results in improved flow accuracy. In most EGR designs, the flow is "Open Loop," in which the system has no feedback mechanism to
