Precaution for Brake Control
- During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is normal.
- Just after starting vehicle, the brake pedal may vibrate or a motor operating noise may be heard from engine compartment. This is a normal status of operation check.
- Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel, or snow-covered (fresh, deep snow) roads.
- When an error is indicated by ABS or another warning lamp, collect all necessary information from customer (what symptoms are present under what conditions) and check for simple causes before starting diagnosis. Besides electrical system inspection, check brake booster operation, brake fluid level, and fluid leaks.
- If incorrect tire sizes or types are installed on the vehicle or brake pads are not Genuine parts, stopping distance or steering stability may deteriorate.
- If there is a radio, antenna or related wiring near control module, ABS function may have a malfunction or error.
- If aftermarket parts (car stereo, CD player, etc.) have been installed, check for incidents such as harness pinches, open circuits or improper wiring.
Scheme 79
Scheme 80
- Do not apply voltage of 7.0V or higher to terminal to be measured.
- Maximum open terminal voltage of tester in use must be less than 7.0V.
- Before checking harnesses, turn ignition switch OFF and disconnect battery negative cable.
- Area to be repaired must be soldered and wrapped with tape. Make sure that fraying of twisted wire is within 110 mm (4.33 in).
- Do not make a bypass connection to repaired area. (If the circuit is bypassed, characteristics of twisted wire will be lost.)
DETAILED FLOW
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | COLLECT THE INFORMATION FROM THE CUSTOMER Get the detailed information from the customer about the symptom (the condition and the environment when the incident/malfunction occurred) using the diagnosis worksheet. Refer to DIAGNOSIS AND REPAIR WORKFLOW: DIAGNOSTIC WORK SHEET . | GO TO 2 | |
| 2 | PERFORM DTC CHECK Check the DTC display with "DTC check" function. Refer to SDT FUNCTION (ABS / ESP®) . Is there any DTC displayed? | GO TO 3 | GO TO 4 |
| 3 | PERFORM THE SYSTEM DIAGNOSIS Perform the diagnosis applicable to the displayed DTC. Refer to DTC NO. INDEX: ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) . | GO TO 7 | |
| 4 | CHECK THE SYMPTOM THAT IS NOT CONSIDERED A SYSTEM MALFUNCTION Check that the symptom is a normal operation that is not considered a system malfunction. Refer to NORMAL OPERATING CONDITION . Is the symptom a normal operation? | Inspection End | GO TO 5 |
| 5 | CHECK THE WARNING LAMP AND INDICATOR LAMP FOR ILLUMINATION Check that the warning lamp and indicator lamp illuminate. ABS warning lamp: Refer to ABS WARNING LAMP CIRCUIT CHECK . Brake warning lamp: Refer to BRAKE WARNING LAMP CIRCUIT CHECK . Is ON/OFF timing normal? | GO TO 6 | GO TO 2 |
| 6 | PERFORM THE DIAGNOSIS BY SYMPTOM Perform the diagnosis applicable to the symptom. | GO TO 7 | |
| 7 | REPAIR OR REPLACE THE MALFUNCTIONING PARTS Repair or replace the specified malfunctioning parts. | GO TO 8 | |
| 8 | FINAL CHECK Perform "DTC check" again, and check that the malfunction is repaired completely. After checking, erase the self-diagnosis memory. Refer to SDT FUNCTION (ABS / ESP®) . Is no other DTC present and the repair completed? | Inspection End | GO TO 3 |
DIAGNOSIS PROCEDURE
Scheme 81
Function
SDT can display each diagnostic item using the diagnostic test modes shown following.
| Diagnostic test mode | Function |
|---|---|
| Utility | This mode enables a technician to adjust some devices faster and more accurately by following the indications on SDT. |
| DTC check | Self-diagnostic results can be read and erased quickly. |
| Data list | Input/Output data in the ABS actuator and electric unit (control unit) can be read. |
| Active Test | Diagnostic test mode is which SDT drives some actuators apart from the ABS actuator and electric unit (control unit) and also shifts some parameters in a specified range. |
| C/U Part Number | ABS actuator and electric unit (control unit) part number can be read. |
| Bus check | The results of transmit/receive diagnosis of CAN communication can be read. |
DIAGNOSTIC TEST MODE REFERENCE CHART
Display Item List
Refer to DTC NO. INDEX: ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) .
| Item (Unit) | Data list item selection | Remarks | ||
|---|---|---|---|---|
| ECU INPUT SIGNALS | MAIN SIGNALS | SELECTION FROM MENU | ||
| FR RH SENSOR (km/h, MPH) | X | X | X | Wheel speed calculated by front RH wheel sensor signal is displayed. |
| FR LH SENSOR (km/h, MPH) | X | X | X | Wheel speed calculated by front LH wheel sensor signal is displayed. |
| RR RH SENSOR (km/h, MPH) | X | X | X | Wheel speed calculated by rear RH wheel sensor signal is displayed. |
| RR LH SENSOR (km/h, MPH) | X | X | X | Wheel speed calculated by rear LH wheel sensor signal is displayed. |
| BATTERY VOLT (V) | X | X | X | Voltage supplied to ABS actuator and electric unit (control unit) is displayed. |
| STOP LAMP SW (ON/OFF) | X | X | X | Stop lamp switch (ON/OFF) status is displayed. |
| ABS WARN LAMP (ON/OFF) | X | X | ABS warning lamp (ON/OFF) status is displayed. | |
| FR LH IN SOL (ON/OFF) | X | X | Front LH IN ABS solenoid (ON/OFF) status is displayed. | |
| FR LH OUT SOL (ON/OFF) | X | X | Front LH OUT ABS solenoid (ON/OFF) status is displayed. | |
| FR RH IN SOL (ON/OFF) | X | X | Front RH IN ABS solenoid (ON/OFF) status is displayed. | |
| FR RH OUT SOL (ON/OFF) | X | X | Front RH OUT ABS solenoid (ON/OFF) status is displayed. | |
| REAR IN SOL (ON/OFF) | X | X | Rear IN ABS solenoid (ON/OFF) status is displayed. | |
| REAR OUT SOL (ON/OFF) | X | X | Rear OUT ABS solenoid (ON/OFF) status is displayed. | |
| MOTOR RELAY (ON/OFF) | X | X | ABS motor relay signal (ON/OFF) status is displayed. | |
| ACTUATOR RLY (ON/OFF) | X | X | ABS actuator relay signal (ON/OFF) status is displayed. | |
| ABS FAIL SIG (ON/OFF) | X | ABS fail signal (ON/OFF) status is displayed. | ||
| EBD FAIL SIG (ON/OFF) | X | EBD fail signal (ON/OFF) status is displayed. | ||
| EBD SIGNAL (ON/OFF) | X | EBD operation (ON/OFF) status is displayed. | ||
| ABS SIGNAL (ON/OFF) | X | ABS operation (ON/OFF) status is displayed. | ||
| EBD WARN LAMP (ON/OFF) | X | Brake warning lamp (ON/OFF) status is displayed. | ||
| CRANKING SIG (ON/OFF) | X | The input state of the key SW START position signal is displayed. | ||
| X: Applicable -: Not applicable | ||||
DISPLAY ITEM CHART
SOLENOID VALVE
- When performing an active test of the ABS / ESP® function, select the "MAIN SIGNALS" for each test item.
- Touch "Up", "Keep", and "Down" on the display screen and confirm that solenoid valves operate as shown in the table below. SOLENOID VALVE REFERENCE CHART Operation ABS solenoid valve Up Keep Down FR RH SOL FR RH IN SOL Off On On FR RH OUT SOL Off Off On (1) FR LH SOL FR LH IN SOL Off On On FR LH OUT SOL Off Off On (1) REAR SOL RR RH IN SOL Off On On RR RH OUT SOL Off Off On (1) RR LH IN SOL Off On On RR LH OUT SOL Off Off On (1) (1) On for 1 to 2 seconds after the touch, and then Off
ABS MOTOR
- Touch "On" and "Off" on screen. Make sure motor relay and actuator relay operate as shown in table below. RELAY SPECIFICATION CHART Operation On Off MOTOR RELAY On Off ACTUATOR RLY On On
SDT MONITOR ITEM
| Monitor item | Display content | Data list | |
|---|---|---|---|
| Condition | Reference value in normal operation | ||
| FR LH SENSOR | Wheel speed | 0 [km/h (MPH)] | Vehicle stopped |
| Nearly matches the speed meter display (± 10% or less) | Vehicle running ( (1) | ||
| FR RH SENSOR | Wheel speed | 0 [km/h (MPH)] | Vehicle stopped |
| Nearly matches the speed meter display (± 10% or less) | Vehicle running ( (1) | ||
| RR LH SENSOR | Wheel speed | 0 [km/h (MPH)] | Vehicle stopped |
| Nearly matches the speed meter display (± 10% or less) | Vehicle running ( (1) | ||
| RR RH SENSOR | Wheel speed | 0 [km/h (MPH)] | Vehicle stopped |
| Nearly matches the speed meter display (± 10% or less) | Vehicle running ( (1) | ||
| STOP LAMP SW | Stop lamp switch signal status | When brake pedal is depressed | ON |
| When brake pedal is released | OFF | ||
| BATTERY VOLT | Battery voltage supplied to the ABS actuator and electric unit (control unit) | Ignition switch ON | 10 - 16 V |
| FR RH IN SOL | Operation status of each solenoid valve | Actuator (solenoid valve) is active ("Active test" with SDT) or actuator relay is inactive (in fail-safe mode) | ON |
| When the actuator (solenoid valve) is not active and actuator relay is active (ignition switch ON) | OFF | ||
| FR RH OUT SOL | Operation status of each solenoid valve | Actuator (solenoid valve) is active ("Active test" with SDT) or actuator relay is inactive (in fail-safe mode) | ON |
| When the actuator (solenoid valve) is not active and actuator relay is active (ignition switch ON) | OFF | ||
| FR LH IN SOL | Operation status of each solenoid valve | Actuator (solenoid valve) is active ("Active test" with SDT) or actuator relay is inactive (in fail-safe mode) | ON |
| When the actuator (solenoid valve) is not active and actuator relay is active (ignition switch ON) | OFF | ||
| FR LH OUT SOL | Operation status of each solenoid valve | Actuator (solenoid valve) is active ("Active test" with SDT) or actuator relay is inactive (in fail-safe mode) | ON |
| When the actuator (solenoid valve) is not active and actuator relay is active (ignition switch ON) | OFF | ||
| REAR IN SOL | Operation status of each solenoid valve | Actuator (solenoid valve) is active ("Active test" with SDT) or actuator relay is inactive (in fail-safe mode) | ON |
| When the actuator (solenoid valve) is not active and actuator relay is active (ignition switch ON) | OFF | ||
| REAR OUT SOL | Operation status of each solenoid valve | Actuator (solenoid valve) is active ("Active test" with SDT) or actuator relay is inactive (in fail-safe mode) | ON |
| When the actuator (solenoid valve) is not active and actuator relay is active (ignition switch ON) | OFF | ||
| MOTOR RELAY | Motor and motor relay operation | When the motor relay and motor are operating | ON |
| When the motor relay and motor are not operating | OFF | ||
| ACTUATOR RLY | Actuator relay operation | When the actuator relay is operating | ON |
| When the actuator relay is not operating | OFF | ||
| ABS WARN LAMP | ABS warning lamp ( (2) | When ABS warning lamp is ON | ON |
| When ABS warning lamp is OFF | OFF | ||
| EBD SIGNAL | EBD operation | EBD is active | ON |
| EBD is inactive | OFF | ||
| ABS SIGNAL | ABS operation | ABS is active | ON |
| ABS is inactive | OFF | ||
| EBD FAIL SIG | EBD fail-safe signal | In EBD fail-safe | ON |
| EBD is normal | OFF | ||
| ABS FAIL SIG | ABS fail-safe signal | In ABS fail-safe | ON |
| ABS is normal | OFF | ||
| CRANKING SIG | Crank operation | Crank is active | ON |
| Crank is inactive | OFF | ||
| EBD WARN LAMP | EBD warning lamp | When EBD warning lamp is ON | ON |
| When EBD warning lamp is OFF | OFF | ||
| (1) Confirm tire pressure is normal. (2) On and off timing for warning lamp and indicator lamp. ABS warning lamp: Refer to ABS WARNING LAMP CIRCUIT CHECK . Brake warning lamp: Refer to BRAKE WARNING LAMP CIRCUIT CHECK . | |||
| (1) | Confirm tire pressure is normal. |
| (2) | On and off timing for warning lamp and indicator lamp. |
SDT MONITOR ITEM CHART
Scheme 82
Fail-Safe: ABS Actuator and Electric Unit (Control Unit)
| CAUTION | If the Fail-Safe function is activated, perform DTC check for ABS system. |
ABS/EBD SYSTEM
In case of an electrical malfunction with the ABS, the ABS warning lamp will turn on. In case of an electrical malfunction with the EBD system, the BRAKE warning lamp and the ABS warning lamp will turn on.
The system will revert to one of the following conditions of the Fail-Safe function.
- For ABS malfunction, only the EBD is operative and the condition of the vehicle is the same condition of vehicles without ABS system.
- For EBD malfunction, the EBD and ABS become inoperative, and the condition of the vehicle is the same as the condition of vehicles without ABS or EBD system.
Normal Operating Condition
| Symptom | Result |
|---|---|
| Slight vibrations are felt on the brake pedal and the operation noises occur, when ABS is activated. | This is a normal condition due to the 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 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. |
| The ABS warning 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. |
| ABS warning lamp may illuminate when running on a special road that is extremely slanted (e.g. bank in a circuit course). |
NORMAL OPERATING CONDITION CHART
PUMP
The pump returns the brake fluid stored in the reservoir to the master cylinder by reducing the pressure.
MOTOR
The motor drives the pump according to the signals transmitted by the ABS actuator and electric unit (control unit).
Component Function Check
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | CHECK ABS WARNING LAMP OPERATION Check that the lamp illuminates for approximately 2 seconds after the ignition switch is turned ON. Is the inspection result normal? | Inspection End | Go to diagnosis procedure. Refer to ABS WARNING LAMP CIRCUIT CHECK . |
ABS WARNING LAMP CIRCUIT DIAGNOSIS PROCEDURE
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | BRAKE WARNING LAMP OPERATION CHECK Check that the lamp illuminates after the ignition switch is turned ON, and turns OFF after the engine is started. Is the inspection result normal? | Inspection End | Go to diagnosis procedure. Refer to BRAKE WARNING LAMP CIRCUIT CHECK . |
BRAKE WARNING LAMP CIRCUIT DIAGNOSIS PROCEDURE
Unexpected Pedal Reaction
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | CHECK BRAKE PEDAL STROKE Check brake pedal stroke. Refer to BRAKE PEDAL INSPECTION AND ADJUSTMENT Is the stroke too large? | Bleed air from brake tube and hose. Refer to BRAKE FLUID: BLEEDING BRAKE SYSTEM Check brake pedal, brake booster, and master cylinder for mount play, looseness, brake system fluid leakage, etc. Refer to BRAKE PEDAL INSPECTION AND ADJUSTMENT (brake pedal), BRAKE MASTER CYLINDER: ON BOARD INSPECTION (master cylinder), BRAKE BOOSTER: INSPECTION (brake booster). | GO TO 2 |
| 2 | CHECK FUNCTION Disconnect ABS actuator and electric unit (control unit) connector to deactivate ABS. Check if braking force is normal in this condition. Connect connector after inspection. Is the inspection result normal? | Normal | Check brake system. |
UNEXPECTED PEDAL REACTION DIAGNOSIS PROCEDURE
The Braking Distance Is Long
| CAUTION | The stopping distance on slippery road surfaces might be longer with the ABS operating than when the ABS is not operating. |
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | CHECK FUNCTION Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector to deactivate ABS. In this condition, check stopping distance. After inspection, connect connector. Is the inspection result normal? | Normal | Check brake system. |
BRAKING DISTANCE IS LONG DIAGNOSIS PROCEDURE
ABS Function Does Not Operate
| CAUTION | ABS does not operate when speed is 10 km/h (6 MPH) or lower. |
| Step | Action | YES | NO |
|---|---|---|---|
| 1 | CHECK ABS WARNING LAMP DISPLAY Make sure that the ABS warning lamp turns OFF after ignition switch is turned ON or when driving. Is the inspection result normal? | Normal | Perform "DTC check". Refer to SDT FUNCTION (ABS / ESP®) . |
ABS FUNCTION DOES NOT OPERATE DIAGNOSIS PROCEDURE
Special Service Tool
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
SPECIAL SERVICE TOOL DESCRIPTION CHART Tool number (Kent-Moore No.) Tool name Description KV991J0080 (J-45741) ABS active wheel sensor tester Checking operation of ABS active wheel sensors ST30031000 (-) Bearing puller Removing sensor rotor
Scheme 83
Scheme 84
Commercial Service Tool
COMMERCIAL SERVICE TOOL DESCRIPTION CHART Tool name Description Flare nut crowfoot Torque wrench Removing and installing brake piping 10 mm (0.39 in)/12 mm (0.47 in) Power tool Removing nuts and bolts
