Chevrolet Sail 2010, Learner’S Manual

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99
Chevrolet 2010 New Sail New Technical Training
- Learner's Manual
Solenoid Valve
Ignition
Open-Circuited or
Short-Circuited against
the Ground
Connected
ConnectedConne
cted
Closed
Brake Switch Not Applicable Connected - Activated
Serial
Communication
Open-Circuited or
Short-Circuited
Connected Connected Activated
5.5 Electronic Brake Control Module
（
EBCM
）
The electronic brake control module
（
EBCM
）
carries out the following major functions to accomplish
effective braking and vehicle stability. In the DDRP
（
decoupled dynamic rear proportioning
）
system, the power of
the rear maintaining solenoid valve is supplied by the ignition circuit.
If one of the following malfunctions occurs, the red brake warning light will be illuminated.
z Wheel speed sensor input malfunction.
z Detection of wheel slip.
z Control braking system in anti-lock control mode malfunction.
z Electrical system operation malfunction.
The electronic brake control module continuously detects the rotation speed of each wheel to determine
whether there is a wheel that starts to slip. Provided that a wheel slip is detected, the electronic brake control
module will require the control valve to move to an appropriate position in order to regulate the pressure of part of
the oil circuit or the entire oil circuit so that the wheel slip is prevented and the best braking effect is obtained. The
electronic brake control module continuously controls the pressure of each oil circuit until the slip disappears. The
electronic brake control module
（
EBCM
）
also continuously monitors whether the operation of the anti-lock
braking system
（
ABS
）
is proper. If a malfunction is detected, the electronic brake control module will shut down
the functions of the anti-lock braking system and illuminate the ABS warning light on the dashboard. In diagnostic
mode, the electronic brake control module also controls the display of the fault diagnosis code of the anti-lock
braking system.
5.6 Solenoid Valve Relay
The solenoid valve relay supplies power for the pump motor and the solenoid valve. The relay switch is
normally open, and must be closed during initialization. As long as the fault diagnosis code that requires the
switch to be open is not set, then the relay switch will remain closed at all times. If the fault diagnosis code is set
to require the relay to be open, then the accumulator voltage of the pump motor and the solenoid valve will be cut
off and the anti-lock braking system
（
ABS
）
won’t function. The relay and the electronic brake control module
are incorporated together and cannot be repaired individually.
5.7 Wheel Speed Sensor and Toothed Ring
Each wheel has a wheel speed sensor, and the sensor transmits the rotation speed of the wheel to the
electronic brake control module in the form of a low AC voltage signal through an interface. This interface might
input a false wheel speed sensor signal, or a wheel speed sensor signal input that contains noise into the electronic
brake control module.