TIAGO

BRAKES

6.9.4 ABS SYSTEM FAILURE WARNING LIGHT

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 diagnostics 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.

Cause of system failure

System

Warning Lamp

ABS

EBD

ABS

EBD

None

Operate

OFF

1. Sensor failure

Does not operate

Operate

OFF

2. Pump failure

Does not operate

Operate

3. Low voltage of battery

Does not operate

Operate (at = 6.5V)

V>8.4 OFF

V<8.4 ON

4. Failure of 2 or more

sensors Valve failure ECU

failure Other failure

Does not operate