RAM 2500 Truck 2WD L6-359 5.9L DSL Turbo VIN D FI (1997)
Powertrain Control Module: Description and Operation
System Operation
Diesel fuel injection system components, except for the intake manifold air heater elements, are not directly regulated by the PCM.
Components not operated or regulated by the PCM:
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Fuel tank
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Fuel tank module
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Low and high-pressure fuel supply lines
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Low-pressure, mechanical, fuel transfer pump (fuel lift pump)
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High-pressure fuel injection pump
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Fuel filter/water separator
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Fuel heater
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Fuel heater relay
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Fuel shutdown solenoid
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Fuel shutdown solenoid relay
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High-pressure fuel injectors
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Fuel return line
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Fuel filter (strainer)
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Fuel drain manifold
The powertrain control module (PCM) is located in the right-rear side of the engine compartment (Fig. 1). It is mounted to the dash panel cowl
with three bolts. The PCM was formerly referred to as the SBEC or engine controller. Except for operation of the intake manifold air heater
elements, the PCM does not regulate or control fuel system operation on the diesel engine.
The PCM is a pre-programmed, dual micro-processor digital computer. Although it does not regulate or control the fuel system on the diesel
powered engine, it does operate or regulate the:
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Speed control system
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Charging system
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Certain warning lamps
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Transmission overdrive solenoid
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Torque convertor engagement
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Certain transmission shift features
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ASD relay
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Air conditioning operation
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Tachometer
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Intake manifold air heater
The PCM can adapt its programming to meet changing operating conditions.
The PCM receives input signals from various switches and sensors. Based on these inputs, the PCM regulates various engine and vehicle
operations through different system components. These components are referred to as PCM Outputs. The sensors and switches that provide inputs
to the PCM are considered PCM Inputs.
PCM inputs:
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A/C request (if equipped with factory A/C)
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A/C select (if equipped with factory A/C)
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Auto shutdown (ASD) sense
