This specification applies to Hydraulic and Electronic Control Unit (HECU) of the Anti lock Braking System(ABS) and
Traction Control System(TCS).
This HECU has the functions as follows:
The HECU shall be put into operation by switching on the operating voltage (IGN).
On completion of the initialization phase, the HECU shall be ready for operation.
In the operating condition, the HECU shall be ready, within the specified limits (voltage and temperature), to process the
signals offered by the various sensors and switches in accordance with the control algorithm defined by the software and to
control the hydraulic and electrical actuators.
The HECU shall receive wheel speed signal from the four inductive wheel sensors.
The wheel signals are converted to square wave by the signal conditioning circuit and given as input to the
µ
- processor.
The sensor connections shall be monitored for short-circuit and inter-ruption and then in the event of 2 sensor failures, the
HECU shall shut down the system.
When one side of the valve coil is connected to the positive voltage that is provided through the valve relay and the other
side is connected to the ground by the MOSFET, the solenoid valve goes into operation.
The electrical function of the valves are always monitored by the valve test pulse under normal operation conditions.
When overvoltage is detected(above 16V), the HECU switches off the valve relay and shuts down the system. When
voltage is returned to operating range, the system goes back to the normal condition after the initialization phase.
In the event of undervoltage(below 10V), ABS control shall be inhibited and the warning lamp shall be turned on.
When voltage is returned to operating range, the warning lamp is switched off and the HECU returns to normal operating
mode.
The pump motor operates when the ABS is functioning.
The HECU performs a pump motor test at a speed of 20km/h once after turned the Ignition switch on. You may hear the
motor operate at this time, but it is normal.
Malfunctions or failures detected by the HECU are encoded on the HECU, stored in a EEPROM and read out by diagnostic
equipment (hi-scan pro) when the ignition switch is turned on.
TIBURON(GK) > 2003 > G 2.7 V6 DOHC > Brake System > ABS(Anti-Lock Brake System) > Description and
Operation, TIBURON(GK) > 2003 > G 2.7 V6 DOHC > Brake System > ABS(Anti-Lock Brake System) > Description
and Operation
DESCRIPTION
- Input of signal from the wheel speed sensors attached to each wheel.
- Control of braking force and traction force
- Failsafe function
- Self diagnosis function
- Interface with the external diagnosis tester
Operation
Warning lamp control
1. ABS warning lamp module
The ABS warning lamp module indicates the operating condition of the ABS.
The ABS warning lamp is turned on under the following conditions.
A. During the initialization phase after ignition switch ON (3 seconds).
B. In the event of inhibition of ABS functions by failure.
C. When the system ECU is shut down even though ignition power is applied.
D. During diagnostic mode.
E. When the HECU connector is disconnected.
2. EBD warning lamp module
The EBD warning lamp module indicates the operating condition of the EBD. However, in case the parking brake switch
is turned on, the EBD warning lamp is always turned on regardless of EBD functions.
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