ABS: System Description
- 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 SDT is available.
ABS: Component Description
| Component parts | Reference | |
|---|---|---|
| ABS actuator and electric unit (control unit) | Pump | [ C1111 ABS MOTOR, MOTOR RELAY SYSTEM ] |
| Motor | ||
| Actuator relay | [ C1140 ACTUATOR RLY ] | |
| Solenoid valve | [ C1120, C1122, C1190 IN ABS SOL ] | |
| Wheel sensor | [ C1101, C1102, C1103, C1104 WHEEL SENSOR-1 ] | |
| Stop lamp switch | ||
| ABS warning lamp | [ ABS WARNING LAMP CIRCUIT CHECK ] | |
| Brake warning lamp | [ BRAKE WARNING LAMP CIRCUIT CHECK ] | |
ABS COMPONENT DESCRIPTION CHART
EBD: System 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 SDT is available.
EBD: Component Description
Refer to ABS: COMPONENT DESCRIPTION .
Scheme 60
Scheme 61
Scheme 62
Scheme 63
Operation Procedure
- Before performing "DTC check", 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).
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 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).
Activates or deactivates each solenoid valve according to the signals transmitted by the ABS actuator and electric unit (control unit).
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.
| 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 |
| NOTE: (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. | |
| NOTE |
|---|
| (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
Excessive ABS Function Operation Frequency
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | CHECK START Check front and rear brake force distribution using a brake tester. Is the inspection result normal? | GO TO 2 | Check brake system. |
| 2 | CHECK FRONT AND REAR AXLE Make sure that there is no excessive play in the front and rear axles. Refer to front: WHEEL HUB: ON-VEHICLE INSPECTION AND SERVICE , Rear: REAR AXLE BEARING: ON-VEHICLE SERVICE (C200) or REAR AXLE BEARING: ON-VEHICLE SERVICE (M226). Is the inspection result normal? | GO TO 3 | Repair or replace malfunctioning components. |
| 3 | CHECK WHEEL SENSOR AND SENSOR ROTOR Check the following. Wheel sensor installation for damage. Sensor rotor installation for damage. Wheel sensor connector connection. Wheel sensor harness inspection. Is the inspection result normal? | GO TO 4 | Replace wheel sensor or sensor rotor. Refer to WHEEL SENSOR: REMOVAL AND INSTALLATION or SENSOR ROTOR: REMOVAL AND INSTALLATION . Repair harness. |
| 4 | CHECK ABS WARNING LAMP DISPLAY Make sure that the ABS warning lamp is turned off after the ignition switch is turned ON or when driving. Is the ABS warning lamp illuminated? | Perform "DTC check". Refer to SDT FUNCTION (ABS / ESP®) . | Normal |
EXCESSIVE ABS FUNCTION DIAGNOSIS PROCEDURE
Pedal Vibration or ABS Operation Sound Occurs
| CAUTION | Under the following conditions, ABS is activated and vibration is felt when brake pedal is lightly depressed. However, this is normal. When shifting gears When driving on slippery road During cornering at high speed When passing over bumps or grooves [at approximately 50 mm (1.97 in) or more] When pulling away just after starting engine [at approximately 10 km/h (6 MPH) or higher] |
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | SYMPTOM CHECK 1 Check that there are pedal vibrations when the engine is started. Do vibrations occur? | GO TO 2 | Inspect the brake pedal. |
| 2 | SYMPTOM CHECK 2 Check that there are ABS operation noises when the engine is started. Do the operation noises occur? | GO TO 3 | Perform self - diagnosis. Refer to SDT FUNCTION (ABS / ESP®) . |
| 3 | SYMPTOM CHECK 3 Check symptoms when electrical component (headlamps, etc.) switches are operated. Do symptoms occur? | Check if there is a radio, antenna, antenna lead wire, or wiring close to the control unit. If there is, move it farther away. | Normal |
PEDAL VIBRATION OR ABS OPERATION SOUND DIAGNOSIS PROCEDURE
