Ford Galaxy / Ford S-MAX. Manual — part 471

Electronic Engine Controls - 1.8L
Duratorq-TDCi (74kW/100PS) -
Lynx/1.8L Duratorq-TDCi (92kW/125PS)
- Lynx - Electronic Engine Controls

S-MAX/Galaxy 2006.5 (02/2006-)

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Description and Operation

General overview

Description

Intake air temperature (IAT) sensor

Camshaft position (CMP) sensor

Engine oil pressure (EOP) sensor

Mass air flow (MAF) sensor

Powertrain control module (PCM)

Fuel rail pressure (FRP) sensor

Fuel pressure regulator

Knock sensor (KS)

Crankshaft position (CKP) sensor

Cylinder head temperature (CHT) sensor

Fuel metering valve

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Fuel temperature sensor

Components

IAT sensor

The IAT sensor is a temperature dependent resistor which has a negative temperature
coefficient, therefore its temperature changes inversely with respect to ambient
temperature. The IAT sensor is supplied with a reference voltage by the PCM. When the
intake air changes temperature, the resistance of the IAT sensor changes therefore
changing the output voltage. The output voltage is assigned to a corresponding intake air
temperature by the PCM.

The signal from the IAT sensor is used as a correction variable for calculating the fuel
injection quantity.

CMP sensor

The CMP sensor uses the Hall effect principle and is supplied with a reference voltage of 5
volts.

During starting, the CKP sensor and the CMP sensor are synchronized. If both signals are
present, the engine will be started.

If the signal from the CMP sensor fails while the engine is running, the engine continues to
run using the signals from the CKP sensor.

If the CMP signal is missing at the next starting operation, it will not be possible to start the
engine.

EOP sensor

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The EOP sensor is located in the cylinder head. The EOP is connected to the instrument
cluster and is not directly part of the electronic engine control system. The EOP sensor
registers engine oil pressure. The sensor opens when a defined oil pressure is reached and
the engine oil pressure warning light is illuminated on the instrument cluster.

MAF sensor

The MAF sensor measures the mass of air entering the intake system, the measurement
being based on the constant temperature hot wire principle. Suspended in a bypass duct
are a hot wire probe and an air temperature probe. The PCM makes sure that the hot wire
probe is always 200ºC hotter than the air temperature probe. The hot wire probe is cooled
by the air flowing through the intake system and the PCM varies the heating current to
maintain the 200ºC temperature difference. The change in heating current is measured as a
voltage drop across a precision resistor and is assigned to a corresponding mass air flow
calculation by the PCM.

PCM

The PCM is attached to the windshield washer reservoir and has 3 electrical connectors with
a total of 128 pins.

The PCM monitors and processes the signals from the sensors. The fuel injectors, the fuel
metering valve and the fuel pressure regulator are also controlled by the PCM.

The PCM can be diagnosed through the data link connector (DLC) using the Worldwide
Diagnostic System (WDS).

FRP sensor

The FRP sensor is located in the fuel rail and measures the fuel pressure within the fuel
system.

The fuel pressure sensor consists of a piezoelectric element that sends a variable voltage
signal to the PCM, as a function of fuel pressure.

The PCM uses this signal to calculate how long the fuel injectors are to be actuated for and
to regulate the fuel pressure by means of the fuel pressure regulator.

Fuel pressure regulator

The fuel pressure regulator is screwed directly onto the high-pressure outlet of the fuel
pump.

The fuel pressure regulator regulates the fuel pressure at the high-pressure outlet and
thereby the fuel pressure to the fuel rail.

In addition, the fuel pressure regulator dampens fuel pressure fluctuations which arise
when the fuel pump is supplying fuel and as a result of the fuel injection process.

KS

In conjunction with the PCM, the KS monitors the combustion process and regulates the
injection period so that predetermined volumes of fuel are injected into the cylinders at
every operating cycle.

By constantly measuring the amount of knock present and adjusting the injection period,
the emission values of the engine remain stable.

CKP sensor

The CKP sensor is an inductive pulse generator which scans 36-1 cast protrusions on the
flywheel. Minus one means that one of the cast protrusions is missing and this gap is
located at 90 degrees before top dead centre. This gap is used by the PCM as a reference
for crankshaft position.