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BRAKES
18
10.ABS SYSTEM FAILURE WARNING LIGHT
Cause of system
Failure
System
Warning Lamp
ABS
EBD
ABS
EBD
None
Operate
Operate
OFF
OFF
1. Sensor Failure
Does not Operate
Operate
ON
OFF
2. Pump Failure
Does not Operate
Operate
ON
ON
Low voltage of battery
Does not Operate
Operate (at = 6.5 V)
ON
V>8.4 OFF
V<8.4 ON
Failure of two or more
sensors valve failure
ECU failure other
failure
Does not Operate
Does not Operate
ON
ON
In normal conditions when the ignition is switched
on the ABS and EBD lamp will come on and then
switch off after 1 - 2 seconds. During this period,
the system will perform a self-diagnostic to confirm
all inputs and outputs are working correctly.
If the ABS warning lamp remains ON after this
time, it means either:
1) The ABS system has not been connected or
2) The system has detected a failure and will need
to be diagnosed.
The EBD lamp is shared with the brake fluid level
and parking brake, hence if the EBD warning lamp
remains on after this time it means either:
1. The park brake is applied
2. The Brake fluid level is low
3. The ABS system has not been connected. or
The system has detected a failure and will need to
be diagnosed.
If the warning light does not come on, the fault
should be sought in the electrical connections (for
ignition switch, ECU), fuse or warning lamp.
If the ABS system detects any fault that may
adversely affect its performance it will switch to a
fail-safe shut down mode. When this happens the
electricity sup- ply to the solenoid valves is
deactivated, stopping control signal output, this
causes the valves to switch to their default state.
(Open for inlet valves / Closed for Outlet valves)
In this condition, the conventional hydraulic in this
condition, the conventional hydraulic brake circuit
will still function, allowing brake pressure to reach
all wheels. It should be noted that with an ABS
fault, it will be possible to lock the wheels and in
the Case of an EBD failure the brake force
proportioning between front and rear will no longer
function and hence rear wheel lock is possible
before front.