Page 201 - Workshop Manual - Aumark (BJ1051)

04-57
Diagnose- ABS system

ABS Can Not Work Effectively

Description
1. Symptom determination

(a) Generally, you can judge if the ABS works normally by observing ABS malfunction
indicator light and emergency brake application with vehicle speed greater than 40km/h.

(b) Operation of ABS malfunction indicator light is shown in the table below:
ABS malfunction indicator light
Ignition switch status Description
status
The light shines for an instant
(approx. 3 seconds) and then goes ABS is normal.
out.
If the light goes out when vehicle speed is greater
than 7km/h, it indicates ABS is normal.
Shines all the time. If the light does not go out when vehicle speed is
Ignition switch: ON greater than 7km/h, it indicates an ABS
malfunction or indicator light line failure.
04
Indicator light line failure or ABS control unit
Does not come on.
malfunction

Tip:

• The ABS indicator light must not go out until vehicle speed is greater than 7km/h (if the
system is OK) after the vehicle is started for the first time or the system has been diagnosed.
Conditions after ignition switch is turned on for the second time are shown in above table.
• If ABS malfunction indicator light shines all the time, you should read DTC first and then
diagnose according to corresponding DTC.
• If no DTC exists, conduct an emergency brake test.

(c) Apply emergency brake on a broad and flat road with vehicle speed greater than 40km/h, and
then observe braking trace. If no braking drag marks exist, it indicates that the ABS works;
if drag marks are seen on all wheels or one wheel and, at the same time, the ABS indicator
light is always lighted up, it indicates that the ABS does not work or the ABS unit on the

wheel does not work. Follow the steps below to perform troubleshooting.
Notice:

The emergency brake test must be carried out in a no man's land in good road conditions.

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