Before test driving a brake complaint vehicle, note
whether the red BRAKE warning lamp, amber ABS
warning lamp, or both are turned on. If it is the red
BRAKE warning lamp, there is a brake hydraulic
problem that must be corrected before driving the
vehicle. Refer to the BASE BRAKE SYSTEM for
diagnosis of the red BRAKE warning lamp. If the red
brake warning lamp is illuminated, there is also a
possibility that there is an ABS problem and the
amber ABS warning lamp is not able to illuminate,
so the MIC turns on the red Brake warning lamp by
default.
If the amber ABS warning lamp is on, test drive
the vehicle as described below. While the amber ABS
warning lamp is on, the ABS is not functional. The
ability to stop the car using the base brake system
should not be affected.
If a functional problem of the ABS is determined
while test driving the vehicle, refer to the Chassis
Diagnostic Procedures manual.
(1) Turn the key to the OFF position and then
back to the ON position. Note whether the amber
ABS warning lamp continues to stay on. If it does,
refer to the diagnostic manual.
(2) If the amber ABS warning lamp goes out, shift
into gear and drive the car to a speed of 25 kph (15
mph) to complete the ABS start-up and drive-off
cycles (see ABS ELECTRONIC DIAGNOSIS). If at
this time the amber ABS warning lamp comes on,
refer to the diagnostic manual.
(3) If the amber ABS warning lamp remains out,
drive the vehicle a short distance. Accelerate the
vehicle to a speed of at least 64 kph (40 mph). Bring
the vehicle to a complete stop, braking hard enough
Fig. 10 Traction Control Hydraulic Circuit
1 – OUTLET VALVE
2 – PUMP PISTON
3 – PUMP MOTOR (ON)
4 – LOW PRESSURE ACCUMULATOR PRESSURE
5 – LOW PRESSURE ACCUMULATOR
6 – NORMALLY CLOSED VALVE (MODULATING)
7 – TO RIGHT FRONT WHEEL (SPINNING)
8 – NORMALLY OPEN VALVE (MODULATING)
9 – NORMALLY OPEN ASR VALVE ON (REGULATING)
10 – FROM MASTER CYLINDER
11 – HYDRAULIC SHUTTLE VALVE
12 – CONTROLLED WHEEL PRESSURE
13 – SUCTION VALVE
14 – PUMP INTERSTAGE PRESSURE
15 – NOISE DAMPER CHAMBER
16 – MASTER CYLINDER PRESSURE
17 – PUMP PRESSURE
LH BRAKES 5 - 65
DIAGNOSIS AND TESTING (Continued)
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