Mazda 2002 6 Workshop Manual page 697

TROUBLESHOOTING (ABS/TCS/DYNAMIC STABILITY CONTROL)
Vehicle with DSC
1. The ABS warning light and/or BRAKE system warning light and/or DSC indicator light and/or TSC OFF light
illuminate even when the system is normal.
Warning lights that may
illuminate and/or flash
• ABS warning light
• BRAKE system warning
light
• DSC indicator light
• DSC OFF light
• Brake system warning
light
• DSC indicator light
• TSC OFF light
2. Precautions during servicing of DSC The DSC is composed of electrical and mechanical parts. It is necessary
to categorize malfunctions as being either electrical or hydraulic when performing troubleshooting.
(1) Malfunction in electrical system
• The control module has an on-board diagnostic function. With this function, the ABS warning light and/
or BRAKE system warning light and/or DSC indicator light and/or TSC OFF light will come on when
there is a problem in the electrical system.
Also, past and present malfunction are recorded in the control module. This function can find
malfunction that do not occur during periodic inspections. Connect the WDS or equivalent to the DLC-2.
The stored malfunction will be displayed in the order of occurrence. To find out the causes of DSC
malfunction, use these on-board diagnostic results.
• If a malfunction occurred in the past but is now normal, the cause is likely a temporary poor connection
of the harness.
The control module usually operates normally. Be careful when searching for the cause of malfunction.
• After repair, it is necessary to clear the DTC from the control module memory.
Also, if the DSC related parts have been replaced, verify that the no DTC has been displayed after
repairs.
• After repairing the ABS wheel-speed sensor or ABS sensor rotor, or after replacing the control module,
the ABS warning light may not go off even when the ignition switch is turned on. In this case, drive the
vehicle at a speed of more than 10 km/h {6.2 mph}, make sure the ABS warning light goes off, and
then clear the DTC.
• When repairing, if the DSC related connectors are disconnected and the ignition switch is turned on,
the control module will mistakenly detect a fault and record it as malfunction.
Caution
• In DSC vehicles, when any DSC HU/CM, steering angle sensor, lateral-G sensor, yaw rate sensor
are replaced. Perform the sensor standard point installation of each sensor.
• To protect the control module, make sure the ignition is off before connecting or disconnecting the
control module connector.
• To protect the terminal, use the SST (ABS/TCS: 49 G066 001, DSC: 49 G066 004) when connecting
the tester lead to the DSC HU connector.
Cases in which the light may
illuminate
Under any of the following
conditions:
• When the front wheels are
jacked up, struck, or
placed on a chassis roller,
and only the front wheel
ABS wheel speed sensors
are spun for more than 60
senconds.
Parking brake is not fully
released while driving.
Brake drag.
Sudden
acceleration/deceleration.
Left/right or front/rear tires are
different. (Size, radius, tire
pressure, or wear is other than
that listed on tire label.)
Battery voltage at DSC HU/
CM ignition terminal drops
below about 9.5 V.
Brake fluid amount is low.
Conditions in which the
light will go out
After turning ignition switch
OFF, vehicle is driven at
speed greater than 10 km/h
{6.2MPH} and normal
operation is confirmed.
Battery voltage rises above
about 9.5 V.
Brake fluid level lower than
recommended amount.
ABS, EBD, TCS and DSC
control
• ABS: Cuts control.
• EBD: Cuts control.
• TCS: Cuts control.
• DSC: Cuts control.
ABS: Operates control.
EBD: Operates control.
TCS: Operates control.
DSC: Operates control.
ABS: Operates control.
EBD: Operates control.
TCS: Cuts control.
DSC: Cuts control.
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