Description And Operation: 2.9L
The Powertrain Control Module (PCM) monitors and manages all engine parameters to optimize performance and fuel consumption by use of real-time responses to different operating conditions.
The PCM management of the 2.9 V6 engine is very complex because of the two separate air feed systems which may operate in different manner independently in some conditions (deactivation of one cylinder row), which requires the use of two PCMs.
The two PCMs (Primary/2 and Secondary/1) manage the various engine systems through sensors and actuators.
Certain components are present on both the right and the left cylinder banks and for this reason there are many duplicate sensors installed to both cylinder banks. There are other sensors which reply to the primary PCM only and other which reply to the secondary PCM only. The two PCMs interface and exchange data on a private Controller Area Network (CAN)-C network data bus.
The primary PCM manages operation of the right cylinder bank, while the secondary PCM manages operation of the left cylinder bank.
In addition, a specific Ignition Control Module (ICM) manages the operation of the certain ignition components such as ignition spark and the coils.
This dual PCM system is designed:
- to achieve the performance goal in terms of power, torque profile and fuel efficiency
- to comply with the emission limits expected in each market.
Depending on the signals received from numerous sensors, the PCM manages the injectors connected to it, handling the following systems:
- direct fuel injection with fuel demand control via a high-pressure pump solenoid valve and high-pressure injection into the combustion chamber;
- right cylinder bank deactivation system (Fuel Saver Mode);
- exhaust emission control by means of one oxygen sensor upstream of each catalyst and one oxygen sensor downstream of each catalyst;
- two turbochargers with supercharge pressure control via Wastegate valve with pneumatic actuator.
In addition to the traditional (high temperature) system which cools the engine coolant, a second system (low temperature) cools the coolant used by the intercoolers by using a specific electronic pump. Finally, the transmission fluid is appropriately cooled by a specific pump.
A specific electronic device arranged on the rear underbody on driver's side governs and controls the operation of the fuel pump which responds to management requests from the PCM. The pump submerged in the tank is brushless (three-phase) and is controlled by the fuel pump module which in turn receives a Pulse-Width Modulated (PWM) signal from the PCM.
The system is also controlled by dedicated relay switches in the engine compartment Power Distribution Center (PDC). Wiring circuits supplying the control unit and various system components (sensors and actuators) are protected by dedicated fuses that are also located in the engine compartment PDC.
Below is a list of sensors and actuators that only respond to PCM Primary and PCM Secondary:
PRIMARY
- RPM sensor
- Engine oil temperature sensor
- Gearbox input shaft revolution sensor
- Turbocharger pressure sensor (right bank)
- Clutch pedal position sensor
- Reversing switch
- Hood switch (where provided)
- HT cooling temperature sensor (where provided)
- Transmission fluid temperature sensor
- Gearbox neutral position sensor
- HT cooling system expansion tank level switch
- Accelerator pedal position sensor
- On/Off lambda sensor downstream of catalytic converter (right bank)
- Broadband planar lambda sensor upstream of catalytic converter (right bank)
- Canister solenoid valve (right bank)
- Dump solenoid valve (right bank)
- CLT cooling circuit electric pump
- PEM module
- Electric fan activation module
- Fuel supply system high-pressure pump flow regulator (right bank)
- Variable displacement oil pump solenoid valve
- Wastegate solenoid valve (right bank)
- Cylinder deactivation solenoid valve (right bank)
- Turbocharger lubrication deactivation solenoid valve (right bank)
- Intake side phase transformer solenoid valve (right bank)
- Exhaust side phase transformer solenoid valve (right bank)
- Injectors (right bank)
- Filter input oil pressure sensor
- Oil pressure sensor of cylinder deactivation circuit (right bank)
- Oil pressure sensor of turbocharger lubrication circuit (right bank)
- Rail fuel high-pressure sensor (right bank)
- Intake air pressure and temperature sensor (right bank)
- Low-pressure system fuel pressure and temperature sensor
- Inlet side timing sensor (right bank)
- Exhaust side timing sensor (right bank)
- Motorized throttle body (right bank)
- Coolant temperature sensor
- Knock sensor (right bank)
- Right bank coils (via Ignition Control Module)
SECONDARY
- Canister diagnostics air pump (where provided)
- turbocharger pressure sensor (left bank)
- Climate control system linear pressure sensor
- Lambda sensor downstream of catalytic converter (left bank)
- Lambda sensor upstream of catalytic converter (left bank)
- Blow-by system diagnostics (where provided)
- Engine oil level and temperature sensor
- Rail fuel high-pressure sensor (left bank)
- Intake air pressure and temperature sensor (left bank)
- Inlet side timing sensor (left bank)
- Exhaust side timing sensor (left bank)
- Motorized throttle body (left bank)
- Knock sensor (left bank)
- Climate control system compressor relay
- Fuel high-pressure pump flow regulator (left bank)
- Wastegate solenoid valve (left bank)
- Intake side phase transformer solenoid valve (left bank)
- Exhaust side phase transformer solenoid valve (left bank)
- Injectors (left bank)
- Left bank coils (via Ignition Control Module)