Ford Falcon. Manual - part 82
206-09-17
Anti Lock Control
206-09-17
DIAGNOSIS AND TESTING (Continued)
Did either of the lamps come on at all whilst driving the
Yes
vehicle?
Go to DIAGNOSTIC
PROCEDURE - PART A, Item
2.
No
Go to 5. Below
5. Select a safe, clear section of road where wheel slip can occur.
Perform an acceleration hard enough to cause wheel slip
NOTE: Perform this test only if the vehicle is equipped with TCS.
Did the TCS lamp flash during the acceleration?
Yes
Return the vehicle to the
customer.
No
Go to DIAGNOSTIC
PROCEDURE - PART A, Item
2.
magnetic fields) may interfere with the electric
Diagnosis of Peculiar ABS Operating
signals being provided to the ABS ECU.
Characteristics
Unless the ABS/TCS Technician has a thorough
Noise, Vibration, Harshness
understanding of the principles behind the operation
ABS/TCS systems make loud noise whilst in
of ABS and TCS systems, it is possible that
operation during heavy braking and TCS systems
misdiagnosis may occur and components may be
make some noise during traction control operation.
replaced unnecessarily. It is therefore recommended
The level of noise experienced in one vehicle may be
that only trained and experienced ABS/TCS
higher than in another, but this does not necessarily
Technicians perform the diagnosis of ABS/TCS
indicate a fault with the noisier vehicle. Typical
concerns.
sources of noise are
ABS/Traction Control Lamp
ABS Modulator - the modulator contains an
electric pump and electrically operated solenoids
If the ABS or traction control warning lamp comes on
that control brake fluid flow. These items all create
or stays illuminated whilst driving, refer to the
noise from the front of the vehicle. If the noise is
Diagnosis Procedure for diagnosis and repair. It is
of a metallic or grinding nature, check the security
likely that one or more DTCs will be present in the
of the brake fluid lines and their proximity to other
ABS ECU memory.
tubes or vehicle bodywork (insulate where
NOTE: The traction control indicator will flash when
necessary). Also check the ABS Modulator rubber
the traction control system is activating traction
bushings for correct installation and contamination
control. If the light flashes only under certain
with small pebbles or dirt.
circumstances, ensure that the potential for wheel
Tyres - during ABS operation the tyres are (by
spin is not the cause.
definition) at the limits of their adhesion. It is
It is possible for the ABS ECU to falsely determine a
normal for tyre squeal and slipping noises to be
fault with the ABS/TCS as a result of completely
heard.
unrelated work taking place on the vehicle. Always
The nature of ABS systems also means that a certain
check the ABS/TCS Concern Customer Questionnaire level of vibration and harshness will be felt during an
for the vehicle history prior to the ABS/TCS concern.
ABS stop. The severity is very much dependent on
Examples include:
the traction between the road surface and tyres.
New tyres fitted recently - under some
Typical instances are
circumstances this can induce a false wheel
Brake Pedal Pulsation - the brake pedal will
speed sensor fault. Perform the ABS/TCS
pulsate underfoot during an ABS stop. This is due
Diagnostic Procedure to confirm correct system
to the action of the ABS modulator in increasing
operation.
and decreasing brake fluid pressures in various
Underinflated tyres / recent puncture - can also
brake circuits.
induce a false wheel speed sensor fault. Inflate all
Whole Vehicle Vibration - an ABS stop involves
tyres to specification, clear DTCs and perform the
the violent application of braking forces to
road test procedure (ABS/TCS Diagnostic
individual wheels in order to stop a vehicle as
Procedure) to confirm correct system operation.
quickly as possible whilst maintaining directional
Electrical interference - under certain
control. It should therefore not be surprising that
circumstances some electrical or electronic
the vehicle occupants feel a high level of pulsating
accessories (or external high strength electric or
force as they are forced forward into their
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