DAF XF105. Manual - part 104

1

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 200528

3-35

Control functions

DMCI ENGINE MANAGEMENT SYSTEM

XF105 series

While the cruise control function is active, the 

speed can still be changed by operating the 

"SET+" (C907 - 4 / C916 - 5) and "SET-" (C907 -

3 / C916 - 6) switches. By briefly operating these 

switches, the speed is adjusted by 0.5 km/h. If 

the "SET+" (C907 - 4 / C916 -5) switch is 

operated for a longer period, the speed 

increases at a specific rate if that is physically 

possible at that moment (gradients, load, etc.). If 

the "SET-" (C907 - 3 / C916 - 6) switch is 

operated for a longer period, the speed 

decreases at a specific rate if that is physically 

possible at that moment (gradients, load, etc.). 

When the cruise control function is active, the 

speed can be increased above the cruise control 

speed using the accelerator pedal. If the 

accelerator pedal is then no longer operated and 

the vehicle speed falls to the cruise control 

speed, the cruise control speed will again be 

maintained.

Conditions for activation
Cruise control can only be activated if:

-

The "OFF" switch is not operated and

-

speed is 

 30 km/h (depending on the 

programmed "v max" setting for special 

applications) and

-

there are no errors in the vehicle speed 

signal and

-

no brake function (service brake, parking 

brake, engine brake and intarder) is active 

and

-

the clutch is not operated and

-

variable vehicle speed limiting is not active 

and

-

no errors have been detected in the steering 

column / steering wheel switch and

-

vehicle speed limiting for special applications 

is not active.

Note:

During the "Downhill Speed Control" function 

the cruise control function will not switch off.

Steering wheel switches C916

K102021

1

3

5

2

4

6

1

DMCI ENGINE MANAGEMENT SYSTEM

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©

 200528

Control functions

XF105 series

Conditions for deactivation
Cruise control is switched off when:

-

The "OFF" switch is operated or

-

the vehicle deceleration is >2 m/s

2

or

-

the vehicle speed becomes lower than 

25 km/h (depending on the programmed 

"v max" setting for special applications) or

-

an error is present in the vehicle speed 

signal or

-

one of the brake functions (service brake, 

parking brake, engine brake and intarder) is 

active or

-

the clutch is operated or

-

variable vehicle speed limiting is switched on 

or

-

an error occurs in the "SET+/SET-" switch or

-

vehicle speed limiting for special applications 

is switched on or

-

the ASR control becomes active or

-

the VSC control becomes active.

Relevant components

-

Stop light relay/brake signal relay (G469)

-

Clutch proximity switch (E575)

-

Accelerator pedal sensor (F672)

-

Injectors (B421 to B426)

-

Pump units (B131 to B136)

-

EBS-2 (D977 via V-CAN2)

-

ABS-D (D850 via V-CAN2)

-

ZF intarder EST-42 (D902 via V-CAN2)

-

VIC-2 (D310 via V-CAN1 and V-CAN2)

-

Steering column switch (C907 via 

V-CAN1)

-

Steering wheel switches (C916 via 

V-CAN1)

-

Parking brake switch (F000 via 

V-CAN1)

-

Engine brake switch (E564 via V-CAN2)

-

BBM (D993 via V-CAN2)

-

Application connector engine speed 

control (A068 via V-CAN2)

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Control functions

DMCI ENGINE MANAGEMENT SYSTEM

XF105 series

3.16 DOWNHILL SPEED CONTROL

The Downhill Speed Control is a speed control 

which ensures that it is possible to drive downhill 

at a constant speed. The vehicle must be 

equipped with steering wheel switches (C916) 

and the combination DEB (DAF Engine Brake) 

with an AS Tronic gearbox. If the vehicle is 

equipped with an intarder then only the intarder is 

used for this function, see"System and 

components information ZF intarder EST42".

By operating the switch (5) "SET" a CAN 

message is sent to VIC-2 which then sends a 

CAN message to DMCI. The speed of the vehicle 

at that moment is stored in DMCI as the desired 

Downhill Speed Control speed. DMCI will first 

control the exhaust brake valve (B192). If the 

speed then decreases then the DEB valves 

(B411 to B416) will also be controlled to maintain 

the desired Downhill Speed Control speed. A 

CAN message will also be sent to AS Tronic to 

select the right gear for the optimum speed range 

for the engine brake operation.

i401015

D965

1 2

high-side

low-side

Cyl.6

B416

1 2

high-side

low-side

Cyl.5

B415

1 2

high-side

low-side

Cyl.4

B414

1 2

high-side

low-side

Cyl.3

B413

1 2

high-side

low-side

Cyl.2

B412

1 2

high-side

low-side

DEB valves

Cyl.1

B411

shield

B192

valve

exh. brake

2

signal

1

supply

supply

supply

C60

C61

C62

Accelerator

Pedal  Sensor

Vehicle

CAN2

low

Vehicle
CAN2
high

E184
(10A)

N

2 1

signal

return

3

F552

speed

crankshaft

A38

C28

A49

A50

A60

A44

A43

A56

A55

A40

A39

A48

A47

A35

A52

A51

ground

signal

supply 5V

ground

signal

CAN2 low

CAN2 high

B A

C D F

F672

B37

B33

B34

B38

B41

B53

B45

Vehicle

CAN1

low

Vehicle
CAN1
high

CAN1 low

CAN1 high

B35

B27

Steering wheel switches C916

K102020

1

3

5

2

4

6

1

DMCI ENGINE MANAGEMENT SYSTEM

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©

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Control functions

XF105 series

If the cruise control is also active then the 

Downhill Speed Control speed will be 

≥ 3km/hour 

higher than the cruise control speed. The function 

can only be activated if the vehicle speed is 

higher than a certain value.

If the speed decreases then DMCI will first 

deactivate the DEB valves to maintain the 

desired Downhill Speed Control speed. If the 

speed decreases further then the exhaust brake 

valve will also be deactivated.

If Downhill Speed Control is active then it is 

possible to brake with the service brake without 

the Downhill Speed Control being deactivated. 

The exhaust brake valve and possibly the DEB 

valves then stay active until the speed falls under 

the Downhill Speed Control speed. If the speed 

then increases above the Downhill Speed Control 

speed then the exhaust brake valve is then first 

activated and the DEB valves if the speed 

continues to increase.

Conditions for activation
Downhill Speed Control can only be activated if:

-

the "OFF" switch (6) is not operated and

-

the speed is 

 30 km/h (depending on the 

programmed "v max" setting for special 

applications) and

-

there are no errors in the vehicle speed 

signal and

-

the clutch is not operated and

-

no errors have been detected in the steering 

wheel switch and

Note:

During the "Downhill Speed Control" function 

the cruise control function will not switch off.