Powertrain Control Module
The Powertrain Control Module (PCM) is located on the left side rear corner of the engine compartment.
The PCM receives inputs from various sensors and outputs reference voltages and signal information to other sensors for engine control.
Inputs:
- Crankshaft Position (CKP) sensor
- Camshaft Position (CMP) sensor
- Brake pedal switch
- Glow plug control module
- HVAC Control Module
- Fuel Pump Driver Module (FPDM)
- Diesel Exhaust Fluid (DEF) tank module
- DEF heater control unit
- Transmission Control Switch (TCS)
- Ambient Air Temperature (AAT) sensor
- Transmission Control Module (TCM)
- Water In Fuel (WIF) sensor
- Generator
- Starter motor
- Active grille air shutter motor
- Engine Coolant Temperature (ECT) sensor - Radiator outlet
- Heated Oxygen Sensor (HO2S)
- Variable Camshaft Timing (VCT) solenoid
- Fuel Rail Pressure (FRP) control valve
- FRP sensor
- Fuel temperature sensor
- Mass Air Flow (MAF)/Intake Air Temperature (IAT) sensor
- Electric throttle
- Cylinder head temperature sensor
- Oil pressure and temperature sensor
- Variable coolant pump - Shroud position
- Variable Geometry Turbine (VGT) vane actuator
- Exhaust gas temperature sensor - Pre catalytic converter
- Exhaust gas pressure sensor
- Manifold Absolute Pressure and Temperature (MAPT) sensor
- High Pressure (HP) Exhaust Gas Recirculation (EGR) valve
- Charge air temperature sensor - EGR cooler outlet
- Charge air cooler temperature sensor
- ECT sensor - electric thermostat housing
- Oil pressure control solenoid
- Exhaust gas temperature sensor - Post catalytic converter
- Cylinder block temperature sensor
- Post Selective Catalyst Reduction (SCR) NOx sensor module (EU6 and NAS only)
- Pre SCR NOx sensor module (NAS only)
- Low Pressure (LP) EGR pressure sensor
- Post SCR sensor module (NAS only)
- Crankcase pressure sensor (NAS only
- Brake vacuum sensor
- Interactive Control Display Module (ICDM).
Outputs:
- Heated Oxygen Sensor (HO2S)
- Variable Camshaft Timing (VCT) solenoid
- Fuel injector (4 off)
- EGR cooler bypass valve solenoid (EU4 and NAS only)
- Variable coolant pump - Shroud solenoid control
- VGT vane actuator
- Turbine Shut-Off Valve (TSOV) Electronic Vacuum Regulating Valve (EVRV) (240PS engine only)
- High Pressure (HP) Exhaust Gas Recirculation (EGR) valve
- Low Pressure (LP) EGR valve
- Fuel metering valve
- Fuel Rail Pressure (FRP) control valve
- Electric thermostat
- Glow plug control module
- Accelerator Pedal Position (APP) sensor
- HVAC Control Module
- Fuel Pump Driver Module (FPDM)
- Diesel Exhaust Fluid (DEF) tank module
- DEF heater control unit
- Generator
- Active air grille shutter motor
- Transmission Control Module (TCM)
- Electric throttle
- Electric cooling fan
- Instrument Cluster (IC).
The Powertrain Control Module (PCM) is connected to the vehicle harnesses via two connectors. The PCM contains data processors and memory microchips. The output signals to the actuators and sensors are in the form of ground paths provided by driver circuits within the PCM. The PCM driver circuits produce heat during normal operation and dissipate this heat via the ribbed casing.
The PCM is connected to other vehicles systems on the FlexRay via the Body Control Module/Gateway Module (BCM/GWM). The PCM also uses a private Controller Area Network (CAN) bus to communicate with the Diesel Exhaust Fluid (DEF) system components.
The PCM performs self-diagnostic routines and stores fault codes in its memory. These fault codes and diagnostics are accessed using an approved diagnostic equipment. If the PCM is to be replaced, the new PCM is supplied 'blank' and must be configured to the vehicle using an approved diagnostic equipment. A 'flash' electrically erasable programmable read only memory allows the PCM to be externally configured, using an approved diagnostic equipment, with market specific or new tune information. The current engine tune data is accessed and read using an approved diagnostic equipment.
When a new PCM is fitted, it must be synchronized to the Body Control Module/Gateway Module (BCM/GWM) assembly using an approved diagnostic equipment. PCMs cannot be 'swapped' between vehicles.
The PCM is connected to the engine sensors which allow it to monitor the engine operating conditions. The PCM processes these signals and determines the actions necessary to maintain optimum engine performance in terms of driveability, fuel efficiency and exhaust emissions. The memory of the PCM is programmed with instructions for how to control the engine, this known as the strategy. The memory also contains data in the form of maps which the PCM uses as a basis for fueling and emission control. By comparing the information from the sensors to the data in the maps, the PCM is able to calculate the various output requirements. The PCM contains an adaptive strategy which updates the system when components vary due to production tolerances or ageing.
Some sensors receive a regulated voltage supplied by the PCM. This avoids incorrect signals caused by voltage drop during cranking.
The PCM receives a vehicle speed signal on the FlexRay from the Anti-lock Brake System (ABS) control module. Vehicle speed is an important input to the PCM strategies. The ABS control module derives the speed signal from the ABS wheel speed sensors. The frequency of this signal changes according to road speed. The PCM uses this signal to determine the following:
- How much to reduce engine torque during gear changes from the Transmission Control Module (TCM).
- When to permit speed control operation.
- To control the operation of the speed control system.
- Implementation of the idle strategy when the vehicle is stationary.
The BCM/GWM passes the following hardwired signals to the PCM:
- Automatic transmission park and neutral switch position.
- Request to crank engine.
- Bus system 'wake-up' message.
- Ignition sense.