DAF XF105. Manual - part 91

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Description of components

DMCI ENGINE MANAGEMENT SYSTEM

XF105 series

The most powerful changes in the magnetic field 

of the sensor take place when the tooth pattern 

(1) on the pulse wheel changes from a tooth to a 

hole and vice versa. A sine-wave alternating 

voltage (2) is generated as a result of this 

changing magnetic field. As a tooth approaches, 

the camshaft sensor signal must be at the 

maximum positive value and then drop to the 

maximum negative value as the end of the tooth 

approaches. This is determined by the sensor 

connections to the electronic unit! The electronic 

unit converts this sine-wave alternating voltage 

signal to a digital signal (3) which it uses to carry 

out calculations.

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Description of components

XF105 series

Sine-wave signals (2) can be measured using an 

oscilloscope with the engine running using the 

tooth pattern on the pulse wheel (1). Each tooth, 

and therefore pulse, corresponds to a specific 

cylinder. The additional tooth before the 

cylinder -1 tooth is the synchronisation tooth (S). 

The pulse this generates is required to realise the 

synchronisation procedure together with the 

crankshaft sensor signal.

Effect of output signal on the system:
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synchronisation during starting;

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cylinder detection;

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calculation of injection timing if crankshaft 

sensor is defective;

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registration of engine speed if crankshaft 

sensor is defective.

-

CAN message engine speed to other vehicle 

systems if the crank shaft sensor is faulty via 

V-CAN1 (AS Tronic, EAS) and V-CAN2 

(VIC-2, ZF intarder EST-42, ABS-D, EBS-2, 

DIP-4, ECAS-4, builder module)

-

output signal engine speed if crankshaft 

sensor is faulty (EMAS, cab lead-through 

connector).

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Description of components

DMCI ENGINE MANAGEMENT SYSTEM

XF105 series

2.10 WASTE GATE VALVE

The waste gate valve controls opening and 

closing of the waste gate on the turbocharger. 

The waste gate valve air supply (6) comes 

directly from the air supply unit circuit 4 (approx. 

10 bar) and is adjusted in the valve to a control 

pressure (9) for the diaphragm housing of the 

waste gate. The waste gate valve checks the 

output pressure using an internal pressure 

sensor (11). The signal issued by the internal 

pressure sensor is compared by the internal 

electronics (2) to the signal from the electronic 

unit. The internal electronics energises the coil 

(3) with a duty cycle (PWM) signal. If the required 

pressure differs from the actual pressure, the 

internal electronics modifies the duty cycle.

Rest position/bleeding
In the rest position or during bleeding, the coil (3) 

is not energised. The piston (8) and valve (5) are 

pushed up by the force of the spring. This also 

pushes up the metal core (4). The outlet (9) is 

now connected to the air bleed vent (7).

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Vent  (3)

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Air connection, waste gate (2) control 

pressure

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Accommodation

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Internal pressure sensor

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Description of components

XF105 series

Constant pressure
When the coil (3) is energised, the metal core (4) 

is pushed down. The valve (5) closes off the 

opening to the air bleed vent on the piston (8). 

The pressure present in the outlet (9) now stays 

constant.

Pressure increase
If the coil (3) remains activated for longer, the 

valve (5) will push the piston (8) further down and 

the air supply opening (6) to the outlet (9) is 

released. This increases the output pressure.

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