Iveco Daily. Manual - part 391

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ELECTRIC/ELECTRONIC SYSTEM

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AILY

Base - May 2004

they inform the control unit which reduces the braking force

activating the supply solenoid valves "12" and the discharge

solenoid valves "13".

At the same time, supplying the motor "5" which drives the

pumps "4", it will be possible to recover the excess oil in the

high pressure accumulators "3".

OPERATING LAYOUT OF THE SYSTEM SHOWING THE PRESSURE REDUCTION PHASE

Figure 127

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Pressure maintenance
Once  the  optimum  braking  force  has  been  reached,  the

control  unit  is  able  to  keep  it  constant  by  no  longer

energising the discharge solenoid valves "13", the motor "5"

and the corresponding recovery pumps "4"; while the supply

solenoid valves "12" continue being energised.

OPERATING LAYOUT OF THE SYSTEM SHOWING THE PRESSURE MAINTENANCE PHASE

Figure 128

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Base - May 2004

C. Any proportioning valve distribution curve - D. EBD system distribution curve

Cutting in of the EBD device
If the sensors detect that one or both rear wheels tend to

lock in relation to the front wheels, they inform the control

unit which appropriately supplies the supply solenoid valves

"12" of the rear axle, in order to optimise the braking force.
A  fault  on  certain  system  components  causes  the  ABS

system  to  be  cut  off  (displayed  by  turning  on  the  special

warning light), still leaving the EBD system operational.

If  both  failure  warning  lights  turn  on  (ABS  and  EBD)  this

means an EBD system failure.
Under  these  conditions  the  braking  force  will  not  be

distributed between the axles, therefore rear wheel locking

may occur with the possibility of skidding.

Figure 129

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Cutting in of the ABD device
If the sensors detect that one or both rear axle wheels tend

to skid, they inform control unit which supplies the intake

solenoid valves "9" drive valves "7".
At the same time, supplying the motor "5" which drives the

pumps "4" it will be possible to generate the pressure to be

sent to the brake calipers concerned.
The braking force generated in this manner is modulated by

solenoid valves "12" and "13".

During this phase the maximum pressure is limited by the

drive solenoid valves "6" and cannot exceed 90 bar.
The driver is informed of the cutting in of this system by the

flashing  of  the  corresponding  warning  light  on  the

dashboard.
If the warning light turns on and glows steadily, there is an

ABD system failure.

ABD DEVICE OPERATING LAYOUT

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Figure 130