The Duramax fuel rail system uses two separate fuel rails, one for each bank of the engine.
Control Strategy
The Duramax 6600 engine uses the following components to control the injection system. Input sensors monitor operating conditions of the engine and inputs from the driver. These inputs are sent to the engine control module (ECM), which processes sensor inputs and generates electrical output signals that get sent to the actuators that operate the engine.
Mass Air Flow (MAF) sensor: Mounted on the intake air assembly, it measures the volume of intake air for fuel delivery calculations.
Intake Air Temperature (IAT) sensor: Integral with the MAF sensor, it identifies intake air temperature for the ECM.
The early intake air heater (IAH) is a coil that is placed in the air intake while later designs used a heated grid in the airflow path.
Intake Air Temperature #2 (IAT 2) sensor ('06-and-newer applications): Located in the intake manifold, this sensor is used to measure post-turbocharger intake air temperature.
Crankshaft Position (CKP) sensor: Mounted in the front engine cover, this identifies engine speed and generates a 57X signal to the ECM.
Camshaft position (CMP) sensor: Located at the front engine cover, this one provides a 3X signal to identify piston position.
Engine Coolant Temperature (ECT) sensor: Usually located on the top front of the engine, the ECT sensor identifies engine coolant values to the ECM.
As you can see, the glow plug controller is different on the Federal-emissions equipped trucks.
Barometric sensor ('01-'05 applications): Found on the left valve cover, it identifies barometric pressure for the ECM. The air pressure reading is used to fine-tune the fuel supply.
Boost Pressure (BP) sensor: Positioned within the intake manifold, the BP sensor measures absolute pressure and functions as a manifold absolute pressure (MAP) sensor.
Fuel Rail Pressure (FRP): This is an input to the ECM to fine-tune output from the high-pressure fuel pump via the fuel rail pressure regulator.
Fuel Temperature (FT) sensor: Located on the return line, it provides a signal to the ECM to fine-tune the fuel delivery.
As you can see, the glow plug controller is different on the Federal-emissions equipped trucks.
Low Oil Level Switch: Mounted in the oil pan, it identifies when the oil level is low.
Brake Switch: This instrument provides an input to the ECM used for fuel delivery and cruise control.
Transmission Range (TR) switch: The ECM uses the transmission gear selection sensors to enhance the idle quality.
Acceleration Pedal Position (APP) sensor: Made up of three individual sensors in one housing, it is mounted on the throttle pedal assembly. Each of the three sensors has a unique range of operation so that sufficient resolution is created for accurate throttle input.
This vane position sensor tells the ECM that the requested vane position has been achieved.
Vane Position Control Solenoid: Operated by the ECM, it controls the variable geometry function of the turbocharger. This is accomplished by altering the pressure and direction of engine oil acting on either side of a hydraulic piston. The piston has a rack of teeth that engage the pinion teeth of a cam. Piston movement causes the cam to rotate and pivot the vanes in the turbocharger. The ECM monitors this action with a vane position sensor.