i am posting this from GM's service information, with a messed up hand so if there is spelling issue, sorry
alot of information is carry over but i felt like posting some highlights to answer some questions if some have them.
we have all waited for this, cant wait till we all drive one
i will add to this if i find anything else
L5P Fuel System Diagram
(1) Secondary Fuel Tank (with N2N)
(2) Fuel Filter with Water in Fuel Sensor
(3) Fuel Heater
(4) Fuel Temperature Sensor
(5) Fuel Pressure Sensor
(6) Exhaust Aftertreatment Fuel Injector
(7) Dual Fuel Rail Pressure Sensor (Contains Fuel Rail Pressure Sensor 1 and Fuel Rail Pressure Sensor 2)
(8) Fuel Rail Assembly
(9) Fuel Rail Pressure Regulator 2
(10) Fuel Pressure Regulator 1 (Located in Fuel Injection Pump)
(11) Fuel Injection Pump
(12) Fuel Injectors
(13) Primary Fuel Tank
(14) Electric 3–Phase Fuel Pump
(15) Fuel Transfer Pump (with N2N)
(16) Fuel Pump Driver Control Module
The primary fuel tank and secondary fuel tank (if equipped) stores the fuel supply. A fuel transfer pump is located in secondary fuel tank to transfer fuel to the primary tank, the primary fuel tank contains a 3–phase electric fuel pump that is controlled by the fuel pump driver control module and engine control module. Fuel is pumped from the primary fuel tank through the fuel feed line to the fuel filter assembly. The fuel filter assembly consists of a fuel filter/water separator, fuel heater, fuel temperature sensor, and a water in fuel sensor. Fuel flows out of the fuel filter assembly through the rear fuel feed pipe to the exhaust aftertreatment fuel injector and past the fuel pressure sensor to the fuel injection pump. High pressure fuel is supplied through the high pressure fuel line to the fuel rails and then through the fuel injector lines to the fuel injectors. High pressure fuel is controlled by the ECM, fuel pressure regulator 1 and fuel pressure regulator 2). Excess fuel returns to the fuel tank through the fuel return pipes.
Fuel Tank Fuel Pump Module
The fuel tank fuel pump module is located inside of the fuel tank. The fuel tank module consists of the following major components:
•The fuel level sensor
•The fuel pump and reservoir assembly
•The fuel strainer
Fuel Level Sensor
The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor card. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor which changes resistance in correspondence with the amount of fuel in the fuel tank. The engine control module (ECM) sends the fuel level information to the instrument panel cluster (IPC). This information is used for the instrument panel (I/P) fuel gauge and the low fuel warning indicator. The ECM also monitors the fuel level input for various diagnostics.
The fuel pump is mounted in the primary fuel tank module reservoir. The engine control module (ECM) supplies voltage to the fuel pump driver control module for 30 s when the ignition is turned on and continuously when the engine is running. While this voltage is being received, the fuel pump driver control module sends a serial data signal to the ECM containing the desired fuel pump speed. The fuel pump driver control module actuates the brushless fuel pump by means of a high power three phase signal.
The fuel strainer attaches to the lower end of the fuel tank fuel pump module. The fuel strainer is made of woven plastic. The functions of the fuel strainer are to filter contaminants and to wick fuel. The fuel strainer is self-cleaning and normally requires no maintenance. Fuel stoppage at this point indicates that the fuel tank contains an abnormal amount of sediment.
Variable Vane Turbocharger Overview
(1) Turbine Housing
(2) Lower Vane Ring
(3) Vane Ring Assembly Spacer
(4) Upper Vane Ring Assembly
(5) Adjusting Ring Assembly
(6) V-Band Nut
(8) Compressor Housing Bolt
(9) Core Assembly
(10) Linkage Assembly
(11) Linkage Assembly Nut
(12) Compressor Housing O-Ring
(13) Actuator Nut
(14) Compressor Housing
The turbocharger increases engine power by pumping compressed air into the combustion chambers, allowing a greater quantity of fuel to combust at the optimal air/fuel ratio. The turbine spins as exhaust gas flows out of the engine and over the turbine blades, and turns the compressor wheel at the other end of the turbine shaft, pumping more air into the intake system. This is a Borg Warner single stage, water cooled, variable geometry turbocharger (VGT) capable of producing 220 kPa (31 psi) boost pressure.
The ECM communicates with the turbocharger vane position actuator via the controller area network (CAN) bus to control the turbocharger vanes. The smart actuator incorporates a brushless motor and is mounted on top of the turbocharger. It is connected to the vanes by a linkage rod. The vanes are used to vary the amount of boost pressure and can control the boost pressure independent of engine speed. The vanes mount to a unison ring which is rotated to change the vane angle. The ECM will vary the vane angle which adjusts the boost dependent upon the load requirements of the engine.
When the actuator arm is in the vertical top rest position the turbocharger vanes are fully open. When the actuator arm is in the horizontal bottom of travel position the turbocharger vanes are fully closed.
The turbocharger vanes are normally open when the engine is not under load. However, the ECM will often close the turbocharger vanes to create back pressure to drive exhaust gas through the Exhaust Gas Recirculation (EGR) valve as required. At extreme cold temperatures, the ECM may close the vanes at low load conditions in order to accelerate engine coolant heating.
The turbocharger is also utilized as a component of the exhaust brake system, if equipped. Under certain conditions, the ECM will automatically close the turbocharger vanes to build back pressure in the exhaust, which reduces engine speed and slows the vehicle without applying the brakes.
During regeneration, the ECM will vary the turbocharger vanes to assist with the exhaust system warm-up, and to maintain proper engine exhaust temperatures needed to properly regenerate the Diesel Exhaust Particulate Filter (DPF).
Each time the ignition is turned off the turbocharger vane position actuator performs a learn procedure. The actuator arm sweeps the turbocharger vanes from fully open to fully closed to obtain a count value. This value is compared to the previous value to ensure proper vane position. Following the learn sweep the actuator sweeps the vanes two more times to clean off combustion soot.
The diesel exhaust aftertreatment system is designed to reduce the levels of hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), and particulate matter remaining in the vehicle’s exhaust gases. Reducing these pollutants to acceptable levels is achieved through a 4 stage process:
1. A close coupled diesel oxidation catalyst (DOC) stage
2. A selective catalyst reduction (SCR) stage
3. A diesel oxidation catalyst (DOC) stage
4. A diesel particulate filter (DPF) stage
In stage 1, the close coupled DOC removes exhaust HC and CO through an oxidation process. After stage 1, reductant, also known as diesel exhaust fluid (DEF) or urea, is injected into the exhaust gases prior to entering the SCR stage. Within the SCR, NOx is converted to nitrogen (N2), carbon dioxide (CO2) , and water vapor (H20) through a catalytic reduction fueled by the injected reductant. The exhaust then enters a second DOC. In the final or stage 4 process, particulate matter consisting of extremely small particles of carbon remaining after combustion are removed from the exhaust gas by the large surface area of the DPF
Close Coupled Diesel Oxidation Catalyst (DOC) Operation
The DOC functions much like the catalytic converter used with gasoline fueled engines. As with all catalytic converters, the DOC must be hot in order to effectively convert the exhaust HC and CO into CO2 and H20. On cold starts, the exhaust gases are not hot enough to create temperatures within the DOC high enough to support full HC and CO conversion. The temperature at which full conversion occurs is known as light-off.
Proper DOC function requires the use of ultra-low sulfur diesel (ULSD) fuel containing less than 15 parts-per-million (ppm) sulfur. Levels above 15 ppm will reduce catalyst efficiency and eventually result in poor driveability and one or more DTCs being set.