Iveco Daily. Manual — part 298
Figure 6
1 - Warning light.
2 - Right level sensor.
3 - Right air spring.
4 - Chassis lifting control push button.
5 - Chassis lowering control push button.
6 - ECU.
7 - Manual chassis levelling control push button.
8 - Left air spring.
9 - Pneumatic supply unit.
10 - Left level sensor.
11 - Centralised diagnostic socket.
Legend
62354
94
REAR AIR SUSPENSIONS
D
AILY
Base - May 2004
62355
The system consists of the following:
- Pneumatic supply unit (electrocompressor, solenoid
valve unit);
- One ECU;
- Two level sensors;
- Two air springs;
- Three levelling push buttons (1, 2, 3);
- One warning light (4).
Level sensors send to ECU the signals corresponding to
chassis-road distance. The ECU processes these signals,
generates accordingly activation signals and sends them to the
electrocompressor.
Turn the ignition key to ”MAR” and depress push buttons (1,
2, 3) for lifting, lowering or activating the self-levelling function
of the chassis.
This system enables vehicle running up to 20 km/h under
whatever height and level condition. When this speed is
exceeded, chassis automatic levelling is activated.
Variation operations are indicated by warning light (4) blinking.
62356
This unit produces the compressed air required to supply the
pneumatic system and enables to bleed air from the
pneumatic system to lower the load bed.
62357
The ECU is the mastermind of the system.
It controls every logic function of suspensions under both
static and dynamic stage.
ECU receives signals from the control switches set in the cab
and lifts and lowers the load bed accordingly. It also receives
signals
from
the
level
sensors
and
controls
the
electrocompressor and the air spring to keep the vehicle in the
self-levelling condition.
ECU indicates any system failure through the dedicated
warning light set on the instrument panel.
Figure 7
Operation
MAIN SYSTEM COMPONENTS
790560
PNEUMATIC SUPPLY UNIT
Specifications and data
Type
Wabco
Lubrication
Dry operation
Max. operating pressure
12.7 bar
Operating temperature
-30 C
° to 65° C
Rated voltage
12V DC
Figure 8
Figure 9
766175
ELECTRONIC CONTROL UNIT
CHASSIS SELF-LEVELLING, LIFTING AND
LOWERING
REAR AIR SUSPENSIONS
95
D
AILY
Base - May 2004
62460
Disconnect the electrical connection (2), loosen the screw
(
⇒) and disconnect the levers. Loosen the fastening screws
and remove the level sensor (1).
62584
Operate on adjustment screws and set relay lever X value to
110 mm.
Perform ECU setting as shown in the relevant paragraphs
”ECU programming/setting”.
Figure 10
ECU programming/setting
WABCO ECU is not requiring programming since it is
supplied already programmed.
Setting can be performed by MODUS, E.A.SY. and IT2000
diagnostic systems and shall be performed when replacing the
following:
-
ECU;
-
level sensor;
-
level sensor levers.
Connect the diagnostic tool to the 38-pin socket and proceed
as follows to obtain correct setting:
-
check and adjust to 110 mm the level sensor lever length,
if required;
-
lift the chassis by depressing the proper video push
button (max. lifting);
-
Insert the special spacers provided (99346151) between
the chassis and the rear axle measuring 65 mm;
-
lower the chassis completely by depressing the proper
video push button (max.lowering);
-
set ECU by depressing the proper video push button.
62358
Level sensors inform constantly the ECU on distance changes
between chassis and road level.
Level sensors consists of a coil secured to the chassis and a
small piston.
When chassis height changes, a cam and a lever linked to the
axle make the piston move inside the coil, thus modifying its
inductance.
These changes will be used by the ECU in the different stages
of the system.
768822
LEVEL SENSOR
Figure 11
Figure 12
Level sensor replacement
Removal
Refitting
Reverse removal operations to perform refitting.
Perform level sensor and ECU setting as shown in the
relevant paragraphs ”ECU programming/setting” and
”Level sensor adjustment”.
Level sensor adjustment
Revi - February 2005
96
REAR AIR SUSPENSIONS
D
AILY
Base - May 2004
62361
Vehicles not fitted with ABS/EBS/ABD systems have been
provided with the following components to obtain brakeforce
distribution:
-
double circuit load sensing valve;
-
load sensing valve pneumatic actuator.
The load sensing valve controls automatically the braking
torque produced by brakes on the rear axle, according to the
load applied on the rear axle, measured and transferred to the
load sensing valve of the pneumatic actuator.
The following diagram shows the brakeforce distribution ratio
corresponding to 0.15 as a function of pneumatic pressure
change inside air springs.
Figure 13
Air spring is an elastic element dedicated to contain pressure
air and to change its extension irrespectively of the applied
load.
62360
Position the vehicle on level ground.
Lift the rear part of the vehicle and rest the chassis on the
proper stands.
Use the hydraulic jack to support the rear axle.
Bleed the system and disconnect the air spring (3) supply pipe
(2).
Loosen upper (1) and lower fastening nuts.
Lower the rear axle and remove the air spring (3).
Air spring replacement
Removal
Figure 14
Figure 15
Figure 16
500731
AIR SPRING
Refitting
Reverse removal operations to perform refitting.
784310
LOAD SENSING VALVE
Legend
A
Hydraulic output pressure in bar;
B
Hydraulic control pressure in bar;
C
Pneumatic control pressure in bar;
D
Characteristic curves, 0.15 ratio (without load);
E
1:1 ratio (with load);
F
Pneumatic pressure/load characteristic curves.
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62362
REAR AIR SUSPENSIONS
97
D
AILY
Base - May 2004
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