Iveco Daily. Manual — part 391

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ELECTRIC/ELECTRONIC SYSTEM

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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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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