PREVOST X3-45 Multiplex, Maintenance Manual

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11
REVISED 5/31/05
To Maximize The Effectiveness Of ESP:
• Loads must be properly secured at all times.
• Drivers need to exercise extreme caution at all times,
and avoid sharp turns, sudden steering inputs or abrupt
lane changes at high speeds, particularly if:
› the vehicle hauls loads that could shift,
› the vehicle or load has a high or off-set center of
gravity (CG) when loaded, or
› the vehicle tows doubles or triples.
Truck Chassis Modifications
If the vehicle’s chassis components are altered (for example,
a wheel base extension or reduction, tag axle addition or
removal, a major body change such as conversion of a
tractor into a truck, or an axle, suspension, or steering system
component modification) the Bendix
®
ESP
®
system must be
disabled. Have a qualified mechanic replace the Advanced
EC-60 ECU with a Premium EC-60 ECU and secure the
X4 connector which will no longer be used. The ATC/ESP
indicator lamp would continue to function as an ATC indicator
lamp, and should be designated as ATC only.
WARNING: If a modified vehicle does not have
the ESP system disabled, serious vehicle braking
and performance issues could result, including
unnecessary ESP system interventions. This can lead
to a loss of control of the vehicle. In addition, remove
all cab signage (e.g. visor labels, etc.) used to show
that Bendix ESP was installed and make any necessary
notations in the vehicle manual(s), so that drivers do
not misunderstand which ABS options are installed
on the vehicle.
Sensor Location Modifications
The location and orientation of the Steering Angle Sensor
and Yaw Rate Sensor must not be altered. When servicing,
an identical component must be used in the same
orientation (using OEM brackets & torque requirements).
During installation follow the OEM leveling guidelines.
Steering Angle Sensor Re-Calibration
Whenever maintenance or repair work is performed to the
steering mechanism, linkage, steering gear, adjustment of
the wheel track, or if the steering angle sensor is replaced,
a recalibration of the Steering Angle Sensor must be
performed.
WARNING! If the Steering Angle Sensor is not
recalibrated, the yaw control system may not function
properly, which can result in incidents leading to loss
of vehicle control. See page 14 of this document for
more details on this procedure.
Dynamometer Test Mode
CAUTION: ATC and ESP must be disabled prior to
conducting any dynamometer testing. When the
Dynamometer Test Mode is engaged, ATC brake control
and engine control along with drag torque control and ESP
are turned off. This test mode is used to avoid torque
reduction or torque increase and brake control activation
when the vehicle is operated on a dynamometer for testing
purpose.
The Dynamometer Test Mode may be activated by pressing
and releasing the diagnostic blink code switch five times or
by using a hand-held or PC-based diagnostic tool.
Advanced EC-60
™
Contollers will remain engaged in the
Dynamometer Test Mode even if power to the ECU is
removed and re-applied. To exit the test mode, press and
release the blink code switch three times, or use a hand-
held or PC-based diagnostic tool.
Automatic Tire Size Calibration
The ECU requires a precise rolling circumference ratio
between steer axle and drive axle tires in order for ABS,
ATC, and ESP to perform in an optimal manner. For this
reason, a continuously monitoring process takes place
in which the precise ratio is calculated. This calculated
value is stored in the ECU memory provided the following
conditions are met:
1. Rolling-circumference ratio is within the permissible
range.
2. Vehicle speed is greater than approximately 12 MPH.
3. No acceleration or deceleration is taking place.
4. There are no active speed sensor diagnostic trouble
codes.
The ECU is provided with a ratio value of 1.00 as a default
setting. If the automatic tire size alignment calculates a
different value, this is used to overwrite the original figure
in the memory. This process adapts the ABS and ATC
function to the vehicle.
Acceptable Tire Sizes
The speed calculation for an exciter ring with 100 teeth is
based on a default tire size of 510 revolutions per mile.
This figure is based on the actual rolling circumference of
the tires, which varies with tire size, tire wear, tire pressure,
vehicle loading, etc.
The ABS response sensitivity is reduced when the actual
rolling circumference is excessive on all wheels. For a 100
tooth exciter ring, the minimum number of tire revolutions
per mile is 426, and the maximum is 567. The ECU will
set diagnostic trouble codes if the number of revolutions
is out of this range.
In addition, the size of the steer axle tires compared to
the drive axle tires also has to be within the ABS system
design. To avoid diagnostic trouble codes, the ratio of the
effective rolling circumference of the steer axle, divided by
the effective rolling circumference of the drive axle, must
be between 0.85 to 1.15.
CAUTION: The ESP system effectiveness relies on the
accuracy of vehicle speed. If a major change on the
tire sizes occurs such that odometer setting needs to
be changed, the Advanced ABS controller's setting of
tire sizes must be reprogrammed to new values at the
same time by a certified mechanic.