Ford Workshop Service and Repair Manuals

The engine is controlled by the PCM (powertrain control module).

The PCM uses various sensors to calculate the optimum ignition timing, the optimum injection quantity and injection time and the position of the throttle. In addition, various corrections are carried out, including adjustment of the ignition timing using the KS (knock sensor) and adjustment of the fuel quantity by the Lambda control. Boost pressure control and fuel pressure control are also performed by the PCM.

For all work on the engine electronics, it is essential to ensure that the connectorsare seated and locked properly.

Powertrain Control Module (PCM)

The PCM communicates with all engine sensors and the other modules. Communication of the PCM with the other modules and the system diagnostics takes place via the CAN (controller area network) data bus.

The following functions are regulated or controlled by the PCM:

• Fuel supply to the engine including lambda control
• Ignition setting including knock control
• Idle speed control
• Control of optimum valve timing via the camshaft adjustment for intake and exhaust camshafts
• The refrigerant compressor is controlled by the air conditioning clutch relay and the delivery of the refrigerant compressor is controlled by a PWM (pulse width modulation) signal.
• Control of EVAP (evaporative emission) purge valve
• Boost pressure control
• Control of the cooling fan
• Charging system (Smart Charge)
• Starting system (Smart Start)

If the PCM is isolated from the vehicle electrical system or the battery is disconnected, the throttle control unit must be initialized.

The PCM is fitted in the engine compartment in the air filter housing. On right hand drive vehicles a protective metal plate is also installed to prevent the plug connector from being pulled off, or make it harder to pull off, in case of theft. The protective plate is secured with a shear bolt. The shear bolt needs to be drilled out in order to remove the protective plate.

Knock Sensor

Two KSs are fitted. They are on the cylinder block, one close to the 2nd cylinder and one close to the 4th cylinder.

When fitting, adhere strictly to the specified tightening torque, otherwise the KS will not work properly.

If the signal from one or both KS is implausible or absent, knock control is deactivated. The PCM switches to an ignition map that is further away from the knock limit. As a result, engine damage caused by combustion knock is avoided. If a fault occurs, a fault code is stored in the error memory of the PCM.

Camshaft Position (CMP) Sensor

If one or both CMP (camshaft position) sensors fail, a fault is saved in the error memory of the PCM and the camshaft adjustment and knock control are deactivated.

Crankshaft Position (CKP) sensor

The CKP (crankshaft position) sensor can be checked during starting by measuring the resistance and/or voltage with the oscilloscope.

The engine cannot work without the CKP signal. A limp-home mode is therefore not possible. The engine is switched off or the engine will not start and a fault is stored in the error memory of the PCM.

Camshaft adjuster solenoid valve

For work on the camshaft adjuster solenoids, extreme cleanliness must be ensured as even slight impurities can result in failure. The camshaft adjustment solenoids for the intake and exhaust camshafts differ only in terms of the position of the fastening point by which they are fixed to the cylinder head cover.

If a fault is detected in the camshaft adjustment solenoids, the solenoids are no longer actuated.

Manifold absolute pressure and temperature sensor

During installation of the MAPT (manifold absolute pressure and temperature) sensor, correct sealing must be ensured to ensure that no infiltrated air can penetrate into the intake manifold from outside.

If the MAP (manifold absolute pressure) sensor fails, the PCM operates with a substitute value.

Accelerator pedal position (APP) sensor

The APP (accelerator pedal position) sensor comprises two separate sensors.

If one of the two APP sensors fails, then only a proportion of the engine's power will be available when accelerating. Top speed can nevertheless be achieved.

If both of the APP sensors fail, the engine is regulated to a defined speed following a plausibility check after the BPP (brake pedal position) switch and brake light switch have been actuated once. The vehicle can then only be accelerated to a defined speed.

In either case, a fault is saved in the error memory of the PCM.

Throttle control unit

CAUTION:The throttle control unit must not be repaired or adjusted. The stop of the throttle valve must on no account be adjusted.

After disconnecting the battery or replacing the throttle control unit or the PCM, initialization is necessary.

• engine off
• Accelerator pedal not pressed
• Battery voltage 11 ... 14 V
• Ignition key in ON position
• Wait approximately 30 seconds until initialization is complete.

Engine Coolant Temperature (ECT) sensor

The ECT (engine coolant temperature) sensor is designed as an NTC (negative temperature coefficient) resistor.

If the signal from the ECT sensor fails, the cooling fan is on all the time and the A/C (air conditioning) is turned off. When the ignition is switched on, the value from the IAT (intake air temperature) sensor is read. When the engine is running, the temperature is calculated using a temperature map stored in the PCM according to how long the engine has been running. This substitute value is then used as the basis for calculating the injected fuel quantity and the ignition timing.

Ignition coil-on-plug

The resistance in the ignition coil primary circuit cannot be checked using a multimeter because the power output stage is integrated into the ignition coil.