BRC-10
< SERVICE INFORMATION >[VDC/TCS/ABS]
SYSTEM DESCRIPTION
SYSTEM DESCRIPTION
SchematicINFOID:0000000001327660
FunctionsINFOID:0000000001327661
VDC
In addition to the TCS/ABS function, the driver
steering amount and brake operation amount are detected
from steering angle sensor and pressure sensor, and the vehicle's driving status (amount of under steering /
over steering) is determined from information from G s ensor, wheel sensor, etc., and this information is used
to improve vehicle stability by controlling the braking and engine power to all four wheels.
SLIP indicator lamp flashes to inform the driver of VDC operation.
During VDC operation, body and brake pedal lightly vibrate and mechanical noises may be heard. This is
normal.
ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp might turn on when vehicle is subject
to strong shaking or large vibration, such as when vehi cle is on a turn table, a ship or a steep slope such as
bank while engine is running. In this case, restart engine on a normal road, and if ABS warning lamp, VDC
OFF indicator lamp, and SLIP indicator lamp turn off, there is no malfunction.
TCS
The wheel spin of the drive wheels is detected by ABS actuator and electric unit (control unit) from the wheel
speed signals from four wheels, so if wheel spin occurs , drive wheel right and left brake fluid pressure con-
trol and engine fuel cut are performed while throttle value is restricted to reduce the engi\
ne torque and
decrease the amount of wheel spin. In addition, the degree throttle is opened is controlled to achieve the
optimum engine torque.
Depending on road circumstances, the driver may have a sluggish feel. This is normal, because the opti-
mum traction has the highest priority under TCS operation.
TCS may be activated any time vehicle suddenly accelerates, suddenly down/upshifts, or is driven on a road with a varying surface friction coefficient.
During TCS operation, it informs a driver of sy stem operation by flashing SLIP indicator lamp.
ABS
The Anti-Lock Braking System is a function that detec ts wheel revolution while braking, and it improves han-
dling stability during sudden braking by electrically prev enting 4 wheel lock. Maneuverability is also improved
for avoiding obstacles.
If the electrical system malfunc tions, then the fail-safe function star ts, the ABS becomes inoperative, and
ABS warning lamp turns on.
Electrical system diagnosis by CONSULT-III is available.
During ABS operation, brake pedal lightly vibrates and a mechanical noise may be heard. This is normal.
When starting engine, or just after starting vehicle, brake pedal may vibrate or motor operating noises may be heard from engine compartment. This is a normal status of operation check.
SFIA1160E
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BRC-32
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Basic Inspection
INFOID:0000000001327676
BRAKE FLUID AMOUNT, LEAKS, AND BRAKE PADS INSPECTION
1. Check fluid level in the brake reservoir tank. If fluid level is low, refill brake fluid.
2. Check brake piping and around ABS actuator and electric uni t (control unit) for leaks. If there is leaking or
oozing fluid, check the following items.
If ABS actuator and electric unit (control unit) connec tion is loose, tighten piping to the specified torque
and re-perform the leak inspection to make sure there are no leaks.
If there is damage to the connection flare nut or AB S actuator and electric unit (control unit) screw,
replace the damaged part and re-perform the leak inspection to make sure there are no leaks.
When there is fluid leaking or oozing from a part other than ABS actuator and electric unit (control unit)
connection, if fluid is just oozing out, use a clean cl oth to wipe off the oozing fluid and re-check for leaks.
If fluid is still oozing out, replace the damaged part.
When there is fluid leaking or oozing at ABS actuator and electric unit (control unit), if fluid is just oozing
out, use a clean cloth to wipe off oozing fluid and re-che ck for leaks. If fluid is still oozing out, replace
ABS actuator and electric unit (control unit) body.
CAUTION:
ABS actuator and electric unit (contr ol unit) body can not be disassembled.
3. Check brake pad degree of wear. Refer to BR-18, "
On-Vehicle Inspection" in “Front Disc Brake” and BR-
24, "On-Vehicle Inspection" in “Rear Disc Brake”
POWER SYSTEM TERMINAL LOOSENESS AND BATTERY INSPECTION
Make sure battery positive cable, negative cabl e and ground connection are not loose. If looseness is
detected, tighten the cables. In additi on, check the battery voltage to make sure it has not dropped and alter-
nator is normal.
ABS WARNING LAMP, VDC OFF INDICATOR LAMP, SLIP INDICATOR LAMP AND BRAKE WARN-
ING LAMP INSPECTION
Symptom Symptom description Result
Motor operation noise This is noise of motor in
side ABS actuator and electr ic unit (control unit).
Slight noise may occur during VDC, TCS, and ABS operation.
Normal
When the vehicle speed goes over 20 km/h (12.5 MPH), motor and valves
operating noise may be heard. It happens only once after ignition switch is
ON. This is a normal status of the system operation check.
System operation check noise When engine starts, slight “click” noise may be heard from engine room.
This is normal and is part of system operation check. Normal
VDC/TCS operation
(SLIP indicator lamp blinking) TCS may activate momentarily if wheel speed changes when driving over
location where friction coefficient varies, when up/downshifting, or when ful-
ly depressing accelerator pedal.
Normal
Cancel the VDC/TCS
function for the inspec-
tion on a chassis dyna-
mometer.
For inspection of speedometer or other instruments, press VDC OFF switch
to turn VDC/TCS function off.
When accelerator pedal is depressed on a chassis dynamometer (fixed
front-wheel type), vehicle speed will not increase. This is not normal. It is re-
sult of TCS being activated by stationary front wheels. Warning lamp may
also illuminate to indicate “sensor system error”. This is also normal, and is
the result of the stationary front wheels being detected. To be certain, restart
engine, and drive vehicle at 30 km/h (19 MPH) or more. Make sure warning
lamp does not illuminate.
ABS operation
(Longer stopping distance) On roads with low friction coefficients, such as snowy roads or gravel roads,
vehicles with ABS may require a longer stopping distance. Therefore, when
driving on such roads, avoid overconfidence and keep speed sufficiently
low.
Normal
Insufficient feeling of accelera-
tion Depending on road conditions, driver may feel that feeling of acceleration is
insufficient. This is because traction control, which controls engine and
brakes to achieve optimal traction, has the highest priority (for safety). As a
result, there may be times when acceleration is slightly less than usual for
the same accelerator pedal operation.
Normal
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