Brake Control: Other Lexus RX II рестайлинг

PRECAUTION

Note. When disconnecting the battery terminal, initialize the following systems after the terminal is reconnected.

SYSTEM NAME PAGE REFERENCE CHART

1. TROUBLESHOOTING PRECAUTIONS When there is a malfunction with terminal contact points or part installation problems, removal and installation of the suspected problem parts may return the system to the normal condition either completely or temporarily. In order to determine the malfunctioning area, be sure to check the conditions at the time the malfunction occurred, such as DTC output and the freeze frame data, and record it before disconnecting each connector or removing and installing parts. Since the system may be influenced by malfunctions in systems other than the brake control system, be sure to check for DTCs in other systems.
2. HANDLING PRECAUTIONS Do not remove or install the Electronically Controlled Brake parts such as the steering sensor, yaw rate sensor or brake pedal stroke sensor except when required, as they cannot be adjusted correctly after removal or installation. Be sure to perform preparation before work and confirmation after work is completed by following the direction in the repair manual when working on the Electronically Controlled Brake system. Be sure to remove and install the ECU, actuator, each sensor, etc. with the ignition switch off unless it is not specified in the inspection procedure. Be sure to remove the 2 main relays before removal and installation, or replacement of the Electronically Controlled Brake parts. The removal or installation of the actuator, master cylinder or stroke simulator as well as some other procedures can cause the fluid level to drop below the fluid reservoir port. If this happens when performing such work, be sure to remove the 2 motor relays until the bleeding of the air in the pipeline is completed. HINT: When the pump motor is operated with the air in the brake actuator hose, bleeding the air becomes difficult due to air in the actuator. The skid control ECU may operate the stroke simulator and drive the pump motor even when the ignition switch is off. With the ignition switch off, the skid control ECU can be operated for 2 minutes after the brake operation is finished. Removal of the main relay and motor relay. Wait for 2 minutes after turning the ignition switch off, stopping the brake pedal operation and closing the driver door before removing the 2 relays. HINT: The above situation occurs when the pump motor operates to prepare for the next operation just before the brake control system turns off. When removing and installing the ECU, actuator and each sensor, be sure to check that the normal display is output in test mode inspection and in DTC output inspection after installing all the parts.
3. DTC PRECAUTION Warnings for some DTCs cannot be cleared only by repairing the malfunctioning parts. If the warning is displayed after repair work, the DTC should be cleared after turning the ignition switch off. NOTE: The DTC for a malfunctioning part that repeats after clearing the code is stored again.
4. CHASSIS DYNAMOMETER PRECAUTION Disable TRAC and VSC control when using a chassis dynamometer. HINT: The vehicle may move unexpectedly out of the dynamometer because of TRAC and VSC operations. Pressing the traction OFF switch does not disable TRAC operation completely. The control will be returned if the vehicle is driven at the speed of 31 mph (50 km/h) or more, or if the vehicle is slipping. NOTE: Make sure that the brake control warning light is blinking (move to test mode). Secure the vehicle with the lock chain for safety.
5. CAN COMMUNICATION SYSTEM PRECAUTION The CAN communication system is used for the data communication between the skid control ECU, the steering sensor, the yaw rate sensor (deceleration sensor included) and other ECUs. If there is trouble with the CAN communication line, corresponding DTCs in the communication line are output. If the DTC in the CAN communication line is output, repair the malfunction in the communication line and troubleshoot the Electronically Controlled Brake system while data communication is normal. Since the CAN communication line has its own length and route, it cannot be repaired temporarily with the bypass wire, etc.

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ECU CONNECTOR TERMINAL REFERENCE CHART

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1. VDIM (Vehicle Dynamics Integrated Management) DESCRIPTION This vehicle is equipped with VDIM (Vehicle Dynamics Integrated Management). It is a concept of vehicle motion control that integrates brake control, drive force control and steering control. Conventional vehicles use a combination of independent functions such as ABS, TRAC, VSC and EPS. However, VDIM integrates these systems to improve "drive, turn and stop", the motion performance of the vehicle in other words. In conventional vehicles, control starts at the limit of the vehicle. However, VDIM exercises control before the limit is reached, creating a smooth vehicle response. This expands the limits of the vehicle, and increases driving pleasure. The VDIM manages all functions, such as the ABS with EBD, the brake assist, the TRAC, and the VSC. It is operated by the Electronically Controlled Brake system, which regulates a brake fluid pressure. The steering cooperative control function is also available. Thus, the VDIM is able to perform the comprehensive management. Conventional brake control systems begin to control either the braking or motive force in order to stabilize the vehicle motion when it becomes unstable due to loss of tire traction. In contrast, in order to maintain stable vehicle control, the VDIM commences controlling the brake and steering systems in accordance with changes in balance before the vehicle becomes unstable. As a result, smooth vehicle control is achieved. Conventional brake control systems manage all related functions, such as the ABS with EBD, the brake assist, the TRAC and the VSC independently, according to the vehicle dynamics. In contrast, the VDIM provides smooth control by seamlessly integrating all those functions.
2. ELECTRONICALLY CONTROLLED BRAKE SYSTEM DESCRIPTION The system detects the degree of brake pedal operation with a brake pedal stroke sensor and two master cylinder pressure sensors, and calculates the optimum hydraulic brake force. The hydraulic pressure source is adjusted based on this so that the optimum hydraulic control is independently performed on all four wheels. Meanwhile, the Electronically Controlled Brake system performs control of the normal brakes, ABS, TRAC, VSC and brake assist in accordance with the operations of the driver. There is a hydraulic backup mechanism that applies master cylinder pressure generated by human power to the wheel cylinder when the brake control stops. In addition, as a fail safe mechanism, when the brake control is malfunctioning, the system excludes the malfunctioning sections and continues to perform brake control on the normal sections. A power backup unit (brake control power supply) is also used to ensure a stable supply of power to the system.
3. FUNCTION DESCRIPTION HINT: The yaw rate sensor and acceleration sensor are combined in a single unit. This unit communicates with the skid control ECU via CAN communication. ABS (Anti-lock Brake System) The ABS helps prevent the wheels from locking when the brakes are applied suddenly and firmly or applied on a slippery surface. Operation description The skid control ECU detects wheel lock condition by receiving vehicle speed signals from each speed sensor, and sends control signals to the solenoid valve. The solenoid valve avoids wheel lock by controlling the oil pressure of each wheel cylinder. The ABS warning light comes on when the ABS system is malfunctioning. EBD (Electronic Brake force Distribution) The EBD control utilizes ABS, performing proper brake force distribution between the front and rear wheels in accordance with driving conditions. When braking while cornering, it also controls the brake forces of the right and left wheels, helping to maintain vehicle behavior. Operation description The skid control ECU receives the speed signal from each speed sensor to detect the slip condition of the wheels and sends the control signal to the solenoid. The solenoid valve controls the oil pressure of each wheel cylinder and splits the control power properly between the front and rear wheels and the right and left wheels. Both of the ABS and BRAKE warning lights come on to indicate a malfunction in the EBD system. BA (Brake Assist) The primary purpose of the brake assist system is to provide auxiliary brake force to assist the driver who cannot generate a brake force large enough during emergency braking, thus helping to maximize the vehicle's brake performance. Operation description The skid control ECU receives the brake pedal stroke sensor signal and the oil pressure signal from the master cylinder pressure sensor to determine whether brake assist is necessary or not. If brake assist is deemed necessary, the skid control ECU will send control signals to the solenoid. The solenoid valve then controls the pressure applied to each wheel cylinder. The ABS warning light comes on to indicate a malfunction in the BA system. TRAC (Traction Control) The TRAC system helps prevent the drive wheels from slipping when the driver presses down on the accelerator pedal excessively while starting off or accelerating on a slippery surface. Operation description The skid control ECU detects vehicle's slip condition by receiving signals from each speed sensor and ECM via CAN communication. The skid control ECU controls engine torque with the ECM via CAN communication and oil pressure through the pump and solenoid valve. The SLIP indicator light blinks when the system is operating. When there is a malfunction in the TRAC system, both brake control warning light and SLIP indicator light come on and DTC will appear on the multi information display. Traction OFF switch stops traction control operation. VSC (Vehicle Stability Control) The VSC system helps prevent the vehicle from slipping sideways as a result of strong front or rear wheel skid during cornering. Operation description The skid control ECU determines vehicle condition by receiving signals from the speed sensor, yaw rate and deceleration sensor and steering angle sensor. The skid control ECU controls engine torque with the ECM via CAN communication, and brake fluid pressure with the solenoid valve. The SLIP indicator light blinks and the skid control buzzer sounds when the system is operating. When there is a malfunction in the VSC system, both brake control warning light and SLIP indicator light come on and DTC will appear on the multi information display.
4. STEERING COOPERATION CONTROL The VDIM system effects coordinated control consisting of VSC and EPS (Electric Power Steering). By integrating these preventive safety functions, the VDIM system ensures higher driving stability and maneuverability performance. If the vehicle loses stability due to a slippage, this function effects brake control by applying hydraulic pressure to the wheels. At the same time, the EPS provides steering torque assist to facilitate the driver's steering maneuver.
5. DYNAMIC RADAR CRUISE CONTROL When a greater deceleration than usual is required while driving in vehicle control mode, braking force is generated by the brake hydraulic pressure control in accordance with the signal from the distance control ECU.
6. PRE-COLLISION CONTROL The pre-collision system predicts frontal collisions with other vehicles or obstructions. By winding up the seat belts prior to collision, and performing brake control and brake assist control, it lessens the impact during the collision. The extremely high frequency radar recognizes if there is a vehicle or obstruction on the road ahead, and the distance control ECU makes a judgment from the position of the object, the speed and the road surface whether a collision is unavoidable. The distance control ECU sends this information via a CAN communication to the seat belt control ECU, suspension control ECU and skid control ECU, to operate each control element of the pre-collision system.
7. FUNCTION OF COMPONENTS COMPONENTS FUNCTION CHART Components Functions Skid control ECU Processes the signals from each sensor to perform brake control for ABS, TRAC, and VSC. In addition, it communicates with the ECM to output a control signal. ABS MAIN relay (ABS No.1 relay, ABS No.2 relay) Controlled by the skid control ECU. In addition to supplying power to each solenoid, it supplies power to the skid control ECU. ABS MOTOR relay (ABS MTR1 relay, ABS MTR2 relay) Controlled by the skid control ECU. Supplies power to the pump motor. Speed sensor Detects the wheel speed and inputs the results to the skid control ECU. Stop light switch Detects the brake operating conditions and inputs the results to the skid control ECU. It supplies power to the skid control ECU. Brake pedal stroke sensor Detects the brake pedal stroke volume and inputs the results to the skid control ECU. Brake control power supply Provides the system with a supplementary power supply by discharging the electric charge of the capacitor. It happens when an electric charge is accumulated in the capacitor in the unit and the vehicle power voltage (12 V) is reduced. Skid control buzzer Sounds intermittently to inform the driver that the VSC is active. Sounds continuously to warn the driver of a reduction in accumulator hydraulic pressure in the brake actuator, an abnormality in the power supply system, or a reduction in the vehicle power voltage (12 V). HV control ECU Controls the engine output during the operation of TRAC and VSC by communicating with the skid control ECU. Yaw rate and deceleration sensor Detects the yaw rate (axial rotation) and the forward, rearward and lateral acceleration, and inputs the results to the skid control ECU. Steering angle sensor Detects the steering angle and direction, and outputs the results to the skid control ECU via CAN communication. Master cylinder Generates pressure in accordance with the force of the brake operation. Brake fluid reservoir Stores brake fluid for the master cylinder system and power supply system. Brake fluid level warning switch Detects a reduction in the level of the brake fluid in the reservoir. Stroke simulator Generates a natural pedal stroke in accordance with the pedal force of the driver during system operation (integrated with the master cylinder). Stroke simulator cut valve (SCSS) Sends brake fluid pressure generated in master cylinder to stroke simulator during system control. Brake actuator Controls the hydraulic pressure of each of the four wheel cylinders using the output signal of the skid control ECU. Pump motor Pumps up the brake fluid from the reservoir and supplies the accumulator with high hydraulic pressure. Accumulator Stores the hydraulic pressure that is generated by the pump. Accumulator pressure sensor (PACC) Built into the brake actuator to detect the accumulator hydraulic pressure. Relief valve Prevents excessive high pressure in the power supply system. It relieves the system by sending brake fluid to the reservoir when the pump has operated continuously, for example, during an accumulator hydraulic pressure sensor malfunction. Master cylinder pressure sensor (PMC1, PMC2) Built into the brake actuator to detect the pressure of the master cylinder and input the results to the skid control ECU. Wheel cylinder pressure sensor (PFR, PFL, PRR, PRL) Built into the brake actuator to detect the brake hydraulic pressure of each wheel cylinder. Switching solenoid valve (SMC1, SMC2) Switches the brake hydraulic pressure route according to whether normal brakes are used, or VDIM (ABS, TRAC and VSC) control are used. Linear solenoid valve (SLA##, SLR##) Controls the wheel cylinder hydraulic pressure during normal brake operation, and VDIM (ABS, TRAC and VSC) control. SLA## are solenoids for controlling pressure increases, while SLR## are solenoids for controlling pressure decreases. ABS warning light Comes on to inform the driver that a malfunction in the ABS or BA has occurred. Blinks to output DTC. BRAKE warning light Comes on to inform the driver that the parking brake is on when the system is normal or the brake fluid has decreased. Brake control warning light Comes on to inform the driver that a malfunction in the Electronically Controlled Brake system has occurred. SLIP indicator light Blinks to inform the driver that TRAC and VSC are operating. Comes on when the traction OFF switch is off to inform the driver of the traction control prohibited state or malfunction in the TRAC and VSC system occurred. Multi information display Comes on to inform the driver that a malfunction in the VSC system has occurred. Display to output DTC.
8. FAIL SAFE When a failure occurs in the ABS with BA & TRAC & VSC systems, the ABS warning light and the brake control warning light come on and ABS with BA & TRAC & VSC operations will be prohibited. In addition to this, when there is a failure that disables the EBD operation, the BRAKE warning light also comes on and the EBD operation is prohibited. If control is prohibited due to a malfunction during operation, control will be disabled gradually. This is to avoid sudden vehicle instability.
9. SERVICE MODE VSC operation can be disabled by operating the intelligent tester. HINT: Refer to the intelligent tester operator's manual for further details.

FREEZE FRAME DATA

1. FREEZE FRAME DATA Whenever a DTC is detected or the ABS operates, the skid control ECU stores the current vehicle (sensor) state as freeze frame data. The skid control ECU stores the number of times (maximum: 31) the ignition switch has been turned from off to the ON position since the last time the ABS was activated. HINT: However, if the vehicle is stopped or at low speed (4.3 mph (7 km/h) or less), or if a DTC is detected, the skid control ECU will stop counting the number since then. Freeze frame data at the time the ABS operates: The skid control ECU stores and updates data whenever the ABS system operates. When the ECU stores data at the time a DTC is detected, the data stored during ABS operation is erased. Freeze frame data at the time a DTC is detected: When the skid control ECU stores data at the time a DTC is detected, no updates will be performed until the data is cleared. Connect the intelligent tester to the DLC3. Turn the ignition switch on. From the display on the tester, select the FREEZE FRAME DATA. FREEZE FRAME DATA REFERENCE VALUE CHART Tester Display Measurement Item Reference Value VEHICLE SPD Vehicle speed reading Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) STOP LAMP SW Stop light switch signal Stop light switch ON: ON, OFF: OFF #IG ON Number of operations of ignition switch on after storing freeze frame data 0 to 31 MAS CYL PRESS 1 Master cylinder pressure sensor reading Brake pedal released: 0.3 to 0.9 V Brake pedal depressed: 0.8 to 4.5 V M/C PRESS GRADE Master cylinder pressure sensor change Min.: -30 MPa/s, Max.: 255 MPa/s YAW RATE Yaw rate sensor reading Min.: -128 deg/s, Max.: 127 deg/s STEERING SEN Steering angle sensor reading Left turn: Increase Right turn: Drop FORWARD & REA G Forward and rearward G Min.: -25.11 m/s 2 , Max.: 24.91 m/s 2 TROUBLE CODE Freeze frame DTC 0 to 65535 BUZZER Skid control buzzer signal Skid control buzzer ON: ON, OFF: OFF PARKING BRAKE SW Parking brake switch signal Parking brake switch ON: ON, OFF: OFF FR WHEEL SPD FR wheel speed reading Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) FL WHEEL SPD FL wheel speed reading Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) RR WHEEL SPD RR wheel speed reading Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) RL WHEEL SPD RL wheel speed reading Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h). LATERAL G Lateral G Min.: -25.11 m/s 2 , Max.: 24.91 m/s 2 GEAR POSITION Gear position information FAIL 1st 2nd 3rd 4th 5th 6th P, N R NOT R LEVER POSITION Shift lever position information FAIL 1st 2nd 3rd 4th 5th 6th/B D/M P, N R TRAC / VSC OFF SW Traction control switch signal Traction control switch ON: ON, OFF: OFF OPERATED SYSTEM Operated system status ABS activated: ABS VSC activated: VSC TRAC activated: TRAC BA activated: BA HAB activated: HAB PBA activated: PBA PB activated: PB Fail safe mode activated: FAIL No system activated: SYS FREEZE TIME Elapsed time after freeze trigger Min.: 0 ms, Max.: 500 ms PEDAL STROKE Stroke sensor reading Min.: 0 V, Max.: 5 V PEDAL STROKE 2 Stroke sensor 2 reading Min.: 0 V, Max.: 5 V FRW/CSENS FR wheel cylinder pressure sensor reading Min.: 0 V, Max.: 5 V FL W/C SENS FL wheel cylinder pressure sensor reading Min.: 0 V, Max.: 5 V RR W/C SENS RR wheel cylinder pressure sensor reading Min.: 0 V, Max.: 5 V RL W/C SENS RL wheel cylinder pressure sensor reading Min.: 0 V, Max.: 5 V ACC PRESS SENS Accumulator pressure sensor reading Min.: 0 V, Max.: 5 V MAS CYL PRESS 2 Master cylinder pressure sensor reading Min.: 0 V, Max.: 5 V MTR VOLTAGE Motor relay voltage value Min.: 0V, Max.: 20 V SLAFR CUR SLAFR solenoid current Min.: 0 A, Max.: 1.5 A SLAFL CUR SLAFL solenoid current Min.: 0 A, Max.: 1.5 A SLARR CUR SLARR solenoid current Min.: 0 A, Max.: 1.5 A SLARL CUR SLARL solenoid current Min.: 0 A, Max.: 1.5 A SLRFR CUR SLRFR solenoid current Min.: 0 A, Max.: 1.5 A SLRFL CUR SLRFL solenoid current Min.: 0 A, Max.: 1.5 A SLRRR CUR SLRRR solenoid current Min.: 0 A, Max.: 1.5 A SLRRL CUR SLRRL solenoid current Min.: 0 A, Max.: 1.5 A FR TARGET OIL FR wheel target oil pressure reading Min.: 0 MPa, Max.: 20 MPa FL TARGET OIL FL wheel target oil pressure reading Min.: 0 MPa, Max.: 20 MPa RR TARGET OIL RR wheel target oil pressure reading Min.: 0 MPa, Max.: 20 MPa RL TARGET OIL RL wheel target oil pressure reading Min.: 0 MPa, Max.: 20 MPa DETAILED CODE Detailed code for freeze frame DTC Min.: 0, Max.: 65535 IG1 VOLTAGE IG1 voltage value Min.: 0 V, Max.: 20 V IG2 VOLTAGE IG2 voltage value Min.: 0 V, Max.: 20 V BS1 VOLTAGE BS1 voltage value Min.: 0 V, Max.: 20 V BS2 VOLTAGE BS2 voltage value Min.: 0 V, Max.: 20 V VM1 VOLTAGE VM1 voltage value Min.: 0 V, Max.: 20 V VM2 VOLTAGE VM2 voltage value Min.: 0 V, Max.: 20 V +B1 VOLTAGE +B1 voltage value Min.: 0 V, Max.: 20 V +B2 VOLTAGE +B2 voltage value Min.: 0 V, Max.: 20 V ELAPSED TIME Elapsed time after ignition switch on Min.: 0 sec, Max.: 100661.76 sec. CAPA MODE Capacitor mode Capacitor mode ON: ON, OFF: OFF SCSS Stroke simulator solenoid (SCSS) signal Stroke simulator solenoid (SCSS) ON: ON, OFF: OFF SMC1 Master cut solenoid (SMC1) signal Master cut solenoid (SMC1) ON: ON, OFF: OFF SMC2 Master cut solenoid (SMC2) signal Master cut solenoid (SMC2) ON: ON, OFF: OFF ECB (1) RELAY ABS main relay signal ABS main relay ON: ON, OFF: OFF ECB (1) RELAY2 ABS main relay 2 signal ABS main relay 2 ON: ON, OFF: OFF ECB (1) MTR RELAY ABS motor relay signal ABS motor relay ON: ON, OFF: OFF ECB (1) MTR RELAY 2 ABS motor relay 2 signal ABS motor relay 2 ON: ON, OFF: OFF RESERVOIR SW Brake fluid level warning switch signal Brake fluid level warning switch ON: ON, OFF: OFF (1) Electronically Controlled Brake

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1. FAIL-SAFE FUNCTION If a malfunction occurs in the skid control ECU, sensor signal, or actuator, rest normally operating parts will maintain brake control. If the brake control is stopped under such conditions as when trouble occurs with a hydraulic pressure source, the pressure generated in the master cylinder by the driver is applied to the wheel cylinder to ensure braking force. A power back-up unit is built in as an additional power source to supply stable power to the system. If the regenerative brake alone does not operate under such conditions as a communication error with the HV ECU, control is switched so that all braking force is generated with the hydraulic pressure brake. TROUBLE AREA REFERENCE CHART Trouble Area Generated braking force Skid control ECU Normally operating parts will control brake and generate braking force Hydraulic pressure controlling parts Normally operating parts will control brake and generate braking force Hydraulic pressure source Braking force generated by the driver