ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Description
After replacing the ABS actuator and electric unit (control unit), perform the following procedures
- Neutral position adjustment for the steering angle sensor
- Calibration of the decel G sensor
ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION : Description
Refer to the table below to determine if adjustment of steering angle sensor neutral position is required.
| X: Required -: Not required | |
|---|---|
| Situation | Adjustment of steering angle sensor neutral position |
| Removing/Installing ABS actuator and electric unit (control unit) | |
| Replacing ABS actuator and electric unit (control unit) | X |
| Removing/Installing steering angle sensor | X |
| Replacing steering angle sensor | X |
| Removing/Installing steering components | X |
| Replacing steering components | X |
| Removing/Installing suspension components | X |
| Replacing suspension components | X |
| Change tires to new ones | |
| Tire rotation | |
| Adjusting wheel alignment | X |
| Battery disconnection | X |
STEERING ANGLE SENSOR NEUTRAL POSITION CHART
CALIBRATION OF DECEL G SENSOR : Description
Refer to the table below to determine if calibration of the decel G sensor is required.
| X: Required -: Not required | |
|---|---|
| Situation | Calibration of decel G sensor |
| Removing/Installing ABS actuator and electric unit (control unit) | |
| Replacing ABS actuator and electric unit (control unit) | X |
| Removing/Installing steering angle sensor | X |
| Replacing steering angle sensor | X |
| Removing/Installing steering components | X |
| Replacing steering components | X |
| Removing/Installing suspension components | X |
| Replacing suspension components | X |
| Change tires to new ones | |
| Tire rotation | |
| Adjusting wheel alignment | X |
DECEL G SENSOR CALIBRATION CHART
System Description
- Vehicle Dynamics Control system detects driver's steering operation amount and brake pedal travel from steering angle sensor and pressure sensors. Using information from yaw rate/side/decel G sensor and wheel sensor, VDC judges driving condition (conditions of under steer and over steer) to improve vehicle driving stability by controlling brake application to 4 wheels and engine output.
- During VDC operation, it informs driver of system operation by flashing SLIP indicator lamp.
- Electrical system diagnosis by CONSULT-III is available.
Scheme 1
Component Description
| Component parts | Reference | |
|---|---|---|
| ABS actuator and electric unit (control unit) | Pump | " DESCRIPTION " |
| Motor | ||
| Actuator relay | " DESCRIPTION " | |
| Solenoid valve | " DESCRIPTION " | |
| VDC switch over valve (CV1, CV2, SV1, SV2) | " DESCRIPTION " | |
| Wheel sensor | " DESCRIPTION " | |
| Yaw rate/side/decel G sensor | " DESCRIPTION " | |
| Steering angle sensor | " DESCRIPTION " | |
| VDC OFF switch | " DESCRIPTION " | |
| ABS warning lamp | " DESCRIPTION " | |
| Brake warning lamp | " DESCRIPTION " | |
| VDC OFF indicator lamp | " DESCRIPTION " | |
| SLIP indicator lamp | " DESCRIPTION " | |
| Front pressure sensor | " DESCRIPTION " | |
| Rear pressure sensor | ||
| Active booster | " DESCRIPTION " | |
| Delta stroke sensor | " DESCRIPTION " | |
COMPONENT DESCRIPTION
- Traction Control System is a function that electronically controls engine torque, brake fluid pressure and A/T gear position to ensure the optimum slippage ratio at drive wheels by computing wheel speed signals from 4 wheel sensors. When ABS actuator and electric unit (control unit) detects a spin at drive wheels (rear wheels), it compares wheel speed signals from all 4 wheels. At this time, LH and RH rear brake fluid pressure are controlled, while fuel being cut to engine and throttle valve being closed to reduce engine torque by the control unit. Further more, throttle position is continuously controlled to ensure the optimum engine torque at all times.
- During TCS operation, it informs driver of system operation by flashing SLIP indicator lamp.
- Electrical system diagnosis by CONSULT-III is available.
Scheme 2
| Component parts | Reference | |
|---|---|---|
| ABS actuator and electric unit (control unit) | Pump | " DESCRIPTION " |
| Motor | ||
| Actuator relay | " DESCRIPTION " | |
| Solenoid valve | " DESCRIPTION " | |
| VDC switch over valve (CV1, CV2, SV1, SV2) | " DESCRIPTION " | |
| Wheel sensor | " DESCRIPTION " | |
| Yaw rate/side/decel G sensor | " DESCRIPTION " | |
| Steering angle sensor | " DESCRIPTION " | |
| VDC OFF switch | " DESCRIPTION " | |
| ABS warning lamp | " DESCRIPTION " | |
| Brake warning lamp | " DESCRIPTION " | |
| VDC OFF indicator lamp | " DESCRIPTION " | |
| SLIP indicator lamp | " DESCRIPTION " | |
| Front pressure sensor | " DESCRIPTION " | |
| Rear pressure sensor | ||
| Active booster | " DESCRIPTION " | |
| Delta stroke sensor | " DESCRIPTION " | |
COMPONENT DESCRIPTION
Scheme 3
- Anti-Lock Braking System is a function that detects wheel revolution while braking, electronically controls braking force, and prevents wheel locking during sudden braking. It improves handling stability and maneuverability for avoiding obstacles.
- Electrical system diagnosis by CONSULT-III is available.
Scheme 4
| Component parts | Reference | |
|---|---|---|
| ABS actuator and electric unit (control unit) | Pump | " DESCRIPTION " |
| Motor | ||
| Actuator relay | " DESCRIPTION " | |
| Solenoid valve | " DESCRIPTION " | |
| Wheel sensor | " DESCRIPTION " | |
| ABS warning lamp | " DESCRIPTION " | |
| Brake warning lamp | " DESCRIPTION " | |
| VDC OFF indicator lamp | " DESCRIPTION " | |
| SLIP indicator lamp | " DESCRIPTION " | |
COMPONENT DESCRIPTION
- Electric Brake force Distribution is a following function. ABS actuator and electric unit (control unit) detects subtle slippages between the front and rear wheels during braking. Then it electronically controls the rear braking force (brake fluid pressure) to reduce rear wheel slippage. Accordingly, it improves vehicle stability.
- Electrical system diagnosis by CONSULT-III is available.
Scheme 5
| Component parts | Reference | |
|---|---|---|
| ABS actuator and electric unit (control unit) | Pump | " DESCRIPTION " |
| Motor | ||
| Actuator relay | " DESCRIPTION " | |
| Solenoid valve | " DESCRIPTION " | |
| Wheel sensor | " DESCRIPTION " | |
| ABS warning lamp | " DESCRIPTION " | |
| Brake warning lamp | " DESCRIPTION " | |
| VDC OFF indicator lamp | " DESCRIPTION " | |
| SLIP indicator lamp | " DESCRIPTION " | |
COMPONENT DESCRIPTION
Operation Procedure
- Before performing the self-diagnosis, start engine and drive vehicle at 30 km/h (19 MPH) or more for approximately 1 minute.
Description
When the sensor rotor rotates, the magnetic field changes. It converts the magnetic field changes to current signals (rectangular wave) and transmits them to the ABS actuator and electric unit (control unit).
When the sensor rotor rotates, the magnetic field changes. It converts the magnetic field changes to current signals (rectangular wave) and transmits them to the ABS actuator and electric unit (control unit).
Supplies electric power to the ABS actuator and electric unit (control unit).
The yaw rate/side/decel G sensor detects the yaw rate/side/decel G affecting the vehicle, and transmits the data to the ABS actuator and electric unit (control unit) as an analog voltage signal.
When the sensor rotor rotates, the magnetic field changes. It converts the magnetic field changes to current signals (rectangular wave) and transmits them to the ABS actuator and electric unit (control unit).
The stop lamp switch transmits the stop lamp switch signal (ON/OFF) to the ABS actuator and electric unit (control unit).
The solenoid valve increases, holds or decreases the fluid pressure of each brake caliper according to the signals transmitted by the ABS actuator and electric unit (control unit).
The solenoid valve increases, holds or decreases the fluid pressure of each brake caliper according to the signals transmitted by the ABS actuator and electric unit (control unit).
ABS actuator and electric unit (control unit) and ECM exchange the engine signal with CAN communication line.
Activates or deactivates each solenoid valve according to the signals transmitted by the ABS actuator and electric unit (control unit).
The front and rear pressure sensors convert the brake fluid pressure to an electric signal and transmit it to the ABS actuator and electric unit (control unit).
The steering angle sensor detects the rotation amount, angular velocity and direction of the steering wheel, and transmits the data to the ABS actuator and electric unit (control unit) via CAN communication.
The brake fluid level switch converts the brake fluid level to an electric signal and transmits it to the ABS actuator and electric unit (control unit).
The steering angle sensor is connected to the ABS actuator and electric unit (control unit) in addition to CAN lines. CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.
The yaw rate/side/decel G sensor detects the yaw rate/side/decel G affecting the vehicle, and transmits the data to the ABS actuator and electric unit (control unit) as an analog voltage signal.
The steering angle sensor detects the rotation amount, angular velocity and direction of the steering wheel, and transmits the data to the ABS actuator and electric unit (control unit) via CAN communication.
The active brake booster consists of a vacuum booster, an active booster control group and a delta stroke sensor. If a brake booster system malfunction occurs due to loss of vacuum, the delta stroke sensor will signal the ABS actuator and electric unit (control unit) that a booster malfunction has occurred. The active booster then applies supplemental force to the master cylinder relative to the amount of force exerted on the brake pedal.
The active brake booster consists of a vacuum booster, an active booster control group and a delta stroke sensor. If a brake booster system malfunction occurs due to loss of vacuum, the delta stroke sensor will signal the ABS actuator and electric unit (control unit) that a booster malfunction has occurred. The active booster then applies supplemental force to the master cylinder relative to the amount of force exerted on the brake pedal.
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.
VDC OFF switch can deactivate (turn OFF) the VDC/TCS function by pressing the VDC OFF switch.
| X: ON -: OFF | |
|---|---|
| Condition | ABS warning lamp |
| Ignition switch OFF | |
| For 2 seconds after turning ON ignition switch | X |
| 2 seconds later after turning ON ignition switch | |
| ABS function is malfunctioning. | X |
| EBD function is malfunctioning. | X |
ABS WARNING LAMP REFERENCE CHART
| X: ON -: OFF | |
|---|---|
| Condition | Brake warning lamp ( (1) ) |
| Ignition switch OFF | |
| Ignition switch ON | X ( (2) ) |
| EBD function is malfunctioning. | X |
| (1) Brake warning lamp will turn on in case of parking brake operation (when switch is ON) or of brake fluid level switch operation (when brake fluid is insufficient). (2) After starting engine, brake warning lamp is turned off. | |
| (1) | Brake warning lamp will turn on in case of parking brake operation (when switch is ON) or of brake fluid level switch operation (when brake fluid is insufficient). |
| (2) | After starting engine, brake warning lamp is turned off. |
BRAKE WARNING LAMP REFERENCE CHART
| X: ON -: OFF | |
|---|---|
| Condition | VDC OFF indicator lamp |
| Ignition switch OFF | |
| For 2 seconds after turning ON ignition switch | X |
| 2 seconds later after turning ON ignition switch | |
| VDC OFF switch turned ON. (VDC function is OFF.) | X |
| VDC/TCS function is malfunctioning. | X |
| ABS function is malfunctioning. | X |
| EBD function is malfunctioning. | X |
VDC OFF INDICATOR LAMP REFERENCE CHART
| X: ON -: OFF | |
|---|---|
| Condition | SLIP indicator lamp |
| Ignition switch OFF | |
| For 2 seconds after turning ON ignition switch | X |
| 2 seconds later after turning ON ignition switch | |
| VDC/TCS function is malfunctioning. | X |
| ABS function is malfunctioning. | X |
| EBD function is malfunctioning. | X |
SLIP INDICATOR LAMP REFERENCE CHART
| Symptom | Result |
|---|---|
| Slight vibrations are felt on the brake pedal and the operation noises occur, when VDC, TCS or ABS is activated. | This is a normal condition due to the VDC, TCS or ABS activation. |
| Stopping distance is longer than that of vehicles without ABS when the vehicle drives on rough, gravel, or snow-covered (fresh, deep snow) roads. | |
| The brake pedal moves and generates noises, when TCS or VDC is activated due to rapid acceleration or sharp turn. | |
| The brake pedal vibrates and motor operation noises occur from the engine room, after the engine starts and just after the vehicle starts. | This is normal, and it is caused by the ABS operation check. |
| Depending on the road conditions, the driver may experience a sluggish feel. | This is normal, because TCS places the highest priority on the optimum traction (stability). |
| TCS may activate momentarily if wheel speed changes when driving over location where friction coefficient varies, when downshifting, or when fully depressing accelerator pedal. | |
| The ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp may turn ON when the vehicle is subject to strong shaking or large vibration, such as when the vehicle is rotating on a turntable or located on a ship while the engine is running. | In this case, restart the engine on a normal road. If the normal condition is restored, there is no malfunction. At that time, erase the self-diagnosis memory. |
| VDC may not operate normally or the ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp may illuminate, when running on a special road that is extremely slanted (e.g. bank in a circuit course). | |
| A malfunction may occur in the yaw rate/side/decel G sensor system, when the vehicle turns sharply, such as during a spin turn, axle turn, or drift driving, while the VDC function is off (VDC OFF indicator lamp illuminated). | |
| The vehicle speed will not increase even though the accelerator pedal is depressed, when inspecting the speedometer on a 2-wheel chassis dynamometer. | Normal (Deactivate the VDC/TCS function before performing an inspection on a chassis dynamometer.) |
| VDC OFF indicator lamp and SLIP indicator lamp may simultaneously turn on when low tire pressure warning lamp turns on. | This is not a VDC system error but results from characteristic change of tire. |
SYMPTOM REFERENCE CHART
- Connect both battery cables. NOTE: Supply power using jumper cables if battery is discharged.
- Use the Intelligent Key or mechanical key to turn the ignition switch to the "ACC" position. At this time, the steering lock will be released.
- Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
- Perform the necessary repair operation.
- When the repair work is completed, return the ignition switch to the "LOCK" position before connecting the battery cables. (At this time, the steering lock mechanism will engage.)
- Perform a self-diagnosis check of all control units using CONSULT-III.
Scheme 6
| WARNING | Clean brake pads and shoes with a waste cloth, then wipe with a dust collector. |
See also:
• CONSULT-III FUNCTION (ENGINE)