System Components
All engine functions are controlled by the Siemens common rail ECM.
ECM
The ECM is a high capacity processor which employs advanced software strategies that continuously control the engines operating parameters. It gathers information from a number of sensors and provides output to the actuators. The ECM also operates a port deactivation system, which closes or opens flaps in the inlet system to provide the optimum swirl and flow conditions throughout the operating range of the engine.
In addition, the ECM controls the actuation of the exhaust gas recirculation (EGR) system, the variable geometry turbochargers and the throttle, giving faster and more accurate response. A full torque-based strategy supports multiple injection control and integration with transmission and braking controllers. Transient torque and boost control enables vehicle performance to be optimized without compromising engine durability.
CKP Sensor
The CKP sensor signal is used to determine
- the quantity of fuel to be injected
- the start of fuel delivery
- the quantity of exhaust gases to be recirculated
The CKP sensor is located at the rear of the crankshaft behind the flywheel.
The CKP sensor is a Hall effect sensor which scans a magnetic disc on the crankshaft. The air gap between the magnetic disc and the CKP is predetermined by the mounting of the sensor.
CMP Sensor
The CMP is located on the cylinder head behind the left-hand camshaft timing belt pulley.
The CMP sensor is Hall effect type and is required to identify cylinder number 1. (This is to synchronize engine to camshaft timing). The sensor scans a web incorporated into the left- hand camshaft timing belt pulley. The air gap between the magnetic ring and the CMP sensor is predetermined by the mounting of the sensor.
ECT Sensor
The ECT sensor is a NTC type sensor and is fitted into the top water outlet hose. The sensor has a bayonet type fitting.
KS
The KS registers increased vibrations which occur due to increased combustion noise. The ECM uses the signal as a correction factor for calculating the quantity and timing of the fuel to be injected during the injection phase.
There are two KS fitted to each bank of the cylinder block.
MAF Sensor
The MAF sensor is used to calculate the air mass. The MAF sensor is capable of detecting the mass air flow extremely precisely.
On engines with a variable turbocharger, the MAF sensor is used solely to control the EGR and not the fuel metering. The MAF sensor also incorporates the intake air temperature (IAT) sensor.
MAP Sensor
The MAP sensor is located in the top of the throttle valve.
The MAP sensor measures the charging pressure in the intake pipe and sends the ECM an analog voltage signal.
Charge Air Temperature Sensor
The charge air temperature sensor measures the intake air or the charge air temperature and supplies the ECM with an analog signal.
The charge air temperature sensor is located in the air intake plenum chamber.
Intake Air Temperature (IAT) Sensor
The IAT sensor measures the intake air temperature and supplies the ECM with an analog signal.
There are two IAT sensors incorporated into the MAF sensor, the LH bank IAT sensor is not monitored by the ECM.
Fuel Rail Pressure (FRP) Sensor
The FRP sensor measures the instantaneous fuel pressure in the fuel rail very precisely within a very short time and supplies a voltage signal according to the pressure. The FRP is located on the fuel diverter rail and must not be removed from the diverter rail. Refer to Fuel Charging and Controls article.
Fuel Temperature Sensor
The fuel temperature sensor measures the temperature of the fuel in the low-pressure system. Air and excessive heat in the fuel system can have an adverse effect on the operation of the sensor.
The fuel temperature sensor is located in the low-pressure side return line behind the throttle body housing.
EOP Sensor
The engine oil pressure (EOP) sensor is located in the left-hand cylinder head. The EOP is connected to the instrument cluster and is not directly part of the electronic engine control system.