ELECTRONICALLY CONTROLLED BRAKE SYSTEM > TERMINALS OF ECU

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CHECK BATTERY VOLTAGE

  1. Measure the battery voltage.

    Voltage:
    10 to 14 V


SKID CONTROL ECU ASSEMBLY INSPECTION

  1. Measure the voltage between each terminal or between each terminal and the body ground.

  2. Connect the intelligent tester to the DCL3, and check the communication condition with the skid control ECU.



  3. Using an oscilloscope, check that the pulse generates between each terminal or between each terminal and the body ground.

    NOTICE:
    1. Inspection should be performed from the back of the connector with the connector connected to the skid control ECU.
    2. The voltage between the terminals of the brake actuator assembly may become 0 V due to the fail safe function when the ECB warning light comes on (malfunctioning).


    F047672E02

    HINT:
    Inspect the ECU from the wire harness side while the connector is connected.


    SKID CONTROL ECU 
    Symbols (Terminal No.)
    		Wiring Color
    		Terminal Description
    		Condition
    		Specified Condition
    GND1 (S41-1) - Body ground
    		W-B - Body ground
    		Skid control ECU ground
    		Always
    		Below 1 Ω
    R1+ (S41-2) - Body ground
    		P - Body ground
    		Main relay power 1
    		IG switch on
    		9.1 to 13.6 V
    BS1 (S41-3) - Body ground
    		B - Body ground
    		Battery source 1
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		8.8 to 14 V
    SMC1 (S41-4) - Body ground
    		Y - Body ground
    		Master cut solenoid 1 output
    		IG switch ON
    Brake pedal depressed approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    +BCTY (S41-5) - Body ground
    		V - Body ground
    		Courtesy power input
    		Driver door open → close
    		Approx. 5 sec. 8 to 16 V
    → Below 1 V
    SLAFR- (S41-6) - Body ground
    		W - Body ground
    		FR solenoid (-) output
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 Ω
    SLAFR+ (S41-7) - Body ground
    		R - Body ground
    		FR solenoid (+) output
    		IG switch ON
    Brake pedal depressed approx. 1.5 sec. after pushing IG switch ON
    		Pulse generation
    (see waveform 1)
    E (S41-8) - Body ground
    		L - Body ground
    		Pressure sensor ground
    		IG switch OFF
    		Below 1 Ω
    VCM1 (S41-9) - Body ground
    		P - Body ground
    		Pressure sensor power
    		IG switch ON
    		4.75 to 5.25 V
    MR1+ (S41-11) - Body ground
    		GR - Body ground
    		Motor relay power 1
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		8.8 to 14 V
    SR1 (S41-12) - Body ground
    		L - Body ground
    		Main relay output 1
    		IG switch ON
    Approx. 1.5 sec. or more after pushing IG switch ON
    		Below 1 V
    SCSS (S41-13) - Body ground
    		BR - Body ground
    		Stroke simulator cut
    		IG switch ON
    Brake pedal depressed
    		Below 1.5 V
    SLARL+ (S41-15) - Body ground
    		L - Body ground
    		RL solenoid (+) output
    		IG switch ON
    Brake pedal depressed approx. 1.5 sec. after pushing IG switch ON
    		Pulse generation
    (see waveform 1)
    SLRRL+ (S41-16) - Body ground
    		W - Body ground
    		RL solenoid (+) output
    		IG switch ON
    Brake pedal depressed approx. 1.5 sec. after pushing IG switch ON
    		Pulse generation
    (see waveform 1)
    SLRFR+ (S41-17) - Body ground
    		Y - Body ground
    		FR solenoid (+) output
    		IG switch ON
    After approx. 1.5 sec., brake pedal depressed → released
    		Pulse generation
    (see waveform 2)
    PRL (S41-18) - Body ground
    		G - Body ground
    		RL pressure sensor input
    		IG switch ON
    Brake pedal released
    		0.3 to 0.8 V
    SG1 (S41-20) - Body ground
    		BR - Body ground
    		Pressure sensor shield ground 1
    		IG switch OFF
    		Below 1 Ω
    PACC (S41-21) - Body ground
    		W - Body ground
    		Accumulator pressure sensor input
    		IG switch ON
    After pump motor operates and stops by pedal operation
    		3.3 to 4.7 V
    FR (S41-22) - Body ground
    		L - Body ground
    		FR sensor (-) input
    		IG switch OFF
    		Below 1 Ω
    PFR (S41-23) - Body ground
    		Y - Body ground
    		FR pressure sensor input
    		IG switch ON
    Brake pedal released
    		0.3 to 0.8 V
    MR1 (S41-25) - Body ground
    		L - Body ground
    		Motor relay output 1
    		IG switch ON
    Pump motor is operating
    		Below 1.5 V
    SLRRL- (S41-26) - Body ground
    		P - Body ground
    		RL solenoid (-) output
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    SLARL- (S41-27) - Body ground
    		LG - Body ground
    		RL solenoid (-) output
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    MTT (S41-29) - Body ground
    		R - Body ground
    		Motor test input
    		IG switch ON
    Pump motor is operating
    		3.5 V or higher
    PMC1 (S41-30) - Body ground
    		R - Body ground
    		Master pressure sensor input 1
    		IG switch ON
    Brake pedal released
    		0.3 to 0.8 V
    PCK1 (S41-31) - Body ground
    		B - Body ground
    		Pressure sensor check output 1
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		4.75 to 5.25 V
    FR+ (S41-32) - Body ground
    		P - Body ground
    		FR sensor (+) input
    		Vehicle speed input
    		Pulse generation
    (see waveform 3)
    SLRFR- (S41-34) - Body ground
    		B - Body ground
    		FR solenoid (-) output
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    GND3 (S40-1) - Body ground
    		W-B - Body ground
    		Skid control ECU ground
    		Always
    		Below 1 Ω
    GND2 (S40-2) - Body ground
    		W-B - Body ground
    		Skid control ECU ground
    		Always
    		Below 1 Ω
    +BI1 (S40-3) - Body ground
    		B - Body ground
    		Main relay power input 1
    		IG switch OFF
    		10 to 14 V
    WFSE (S40-4) - Body ground
    		GR - Body ground
    		Mode control signal input
    		IG switch ON
    		9.1 to 13.6 V
    +BO1 (S40-5) - Body ground
    		Y - Body ground
    		Main relay power output 1
    		IG switch ON
    		8.8 to 14 V
    IG1 (S40-7) - Body ground
    		B - Body ground
    		IG1 power
    		IG switch ON
    		10 to 14 V
    RRS (S40-10) - Body ground
    		BR - Body ground
    		Speed sensor shield ground
    		IG switch OFF
    		Below 1 Ω
    BZ (S40-12) - Body ground
    		BR - Body ground
    		Warning buzzer output
    		IG switch ON
    Buzzer is operating
    		Below 1 V
    STP (S40-14) - Body ground
    		R - Body ground
    		Stop light switch signal input
    		IG switch ON
    Brake pedal depressed → released
    		10 to 12 V
    → Below 1.5 V
    CAN-L (S40-18) - Body ground
    		W - Body ground
    		CAN communication
    (Send and receive-)
    		Check DTC using intelligent tester
    		CAN communication's
    DTC is not output
    CAN-H (S40-19) - Body ground
    		B - Body ground
    		CAN communication
    (Send and receive+)
    		Check DTC using intelligent tester
    		CAN communication's
    DTC is not output
    FAIL (S40-20) - Body ground
    		P - Body ground
    		Capacitor communication
    (Receive)
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Pulse generation
    (see waveform 5)
    SP1 (S40-22) - Body ground
    		V - Body ground
    		Speedometer output
    		Vehicle speed input
    		Pulse generation
    (see waveform 4)
    RLO (S40-25) - Body ground
    		P - Body ground
    		RL speed signal output
    		Vehicle speed output
    		Pulse generation
    (see waveform 7)
    RL- (S40-27) - Body ground
    		B - Body ground
    		RL sensor (-) input
    		IG switch OFF
    		Below 1 Ω
    D/G (S40-28) - Body ground
    		W - Body ground
    		Diagnosis output
    		IG switch ON
    		9.1 to 13.6 V
    ENA (S40-30) - Body ground
    		B - Body ground
    		Capacitor communication
    (Send)
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Pulse generation
    (see waveform 6)
    TS (S40-32) - Body ground
    		L - Body ground
    		Sensor diagnosis check input
    		IG switch ON
    		Below 1.5 V
    → 9.1 to 13.6 V
    VBZ (S40-33) - Body ground
    		B - Body ground
    		Warning buzzer power
    		IG switch ON
    		9.1 to 13.6 V
    RL+ (S40-35) - Body ground
    		W - Body ground
    		RL sensor (+) input
    		Vehicle speed input
    		Pulse generation
    (see waveform 3)
    GND5 (S39-1) - Body ground
    		W-B - Body ground
    		Skid control ECU ground
    		Always
    		Below 1 Ω
    GND4 (S39-2) - Body ground
    		W-B - Body ground
    		Skid control ECU ground
    		Always
    		Below 1 Ω
    +BO2 (S39-4) - Body ground
    		W - Body ground
    		Main relay power output 2
    		IG switch ON
    		8.8 to 14 V
    +BI2 (S39-5) - Body ground
    		R - Body ground
    		Main relay power input 2
    		IG switch OFF
    		10 to 14 V
    VCSK (S39-6) - Body ground
    		B - Body ground
    		Stroke sensor power
    		IG switch ON
    		3.75 to 4.95 V
    SSK (S39-7) - Body ground
    		Shielded - Body ground
    		Stroke sensor shield ground
    		IG switch OFF
    		Below 1 Ω
    SKG (S39-8) - Body ground
    		W - Body ground
    		Stroke sensor power
    		IG switch OFF
    		Below 1 Ω
    PKB (S39-14) - Body ground
    		R - Body ground
    		Parking brake signal input
    		Parking brake applied → released
    		Below 1.5 V
    → 9.1 to 13.6 V
    SKS1 (S39-21) - Body ground
    		R - Body ground
    		Stroke sensor signal input 1
    		IG switch ON
    Brake pedal released
    		0.46 to 1.35 V
    SKS2 (S39-22) - Body ground
    		G - Body ground
    		Stroke sensor signal input 2
    		IG switch ON
    Brake pedal released
    		2.56 to 4.35 V
    RR- (S39-23) - Body ground
    		B - Body ground
    		RR sensor (-) input
    		IG switch OFF
    		Below 1 Ω
    EXI (S39-24) - Body ground
    		G - Body ground
    		Cruise relay ON signal input
    		Cruise control brake
    OFF → ON
    		Below 1 Ω
    → 10 to 14 V
    RR+ (S39-31) - Body ground
    		W - Body ground
    		RR sensor (+) input
    		Vehicle speed input
    		Pulse generation
    (see waveform 3)
    RRO (S39-33) - Body ground
    		O - Body ground
    		RR speed signal output
    		Vehicle speed output
    		Pulse generation
    (see waveform 7)
    SLAFL+ (S38-1) - Body ground
    		P - Body ground
    		FL solenoid (+) output
    		IG switch ON
    Brake pedal depressed approx. 1.5 sec. after pushing IG switch ON
    		Pulse generation
    (see waveform 1)
    SLAFL- (S38-2) - Body ground
    		O - Body ground
    		FL solenoid (-) output
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    SMC2 (S38-3) - Body ground
    		LG - Body ground
    		Master cut solenoid 2 output
    		IG switch ON
    Brake pedal depressed approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    IG2 (S38-5) - Body ground
    		O - Body ground
    		IG2 power
    		IG switch ON
    		10 to 14 V
    LBL (S38-6) - Body ground
    		P - Body ground
    		Brake fluid level switch input
    		Reservoir level switch
    OFF → ON
    		4 to 4.65 V
    → Below 1.5 V
    BS2 (S38-7) - Body ground
    		P - Body ground
    		Battery source 2
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		8.8 to 14 V
    SLRFL+ (S38-8) - Body ground
    		Y - Body ground
    		FL solenoid (+) output
    		IG switch ON
    After approx. 1.5 sec., brake pedal depressed → released
    		Pulse generation
    (see waveform 2)
    SLARR- (S38-9) - Body ground
    		P - Body ground
    		RR solenoid (-) output
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    CR (S38-11) - Body ground
    		G - Body ground
    		Cruise relay output
    		Cruise control brake
    OFF → ON
    		Below 1 V
    → 10 to 14 V
    SG2 (S38-12) - Body ground
    		Shielded - Body ground
    		Pressure sensor shield ground 2
    		IG switch OFF
    		Below 1 Ω
    FSS (S38-13) - Body ground
    		BR - Body ground
    		Speed sensor shield ground
    		IG switch OFF
    		Below 1 Ω
    VCM2 (S38-14) - Body ground
    		B - Body ground
    		Pressure sensor power 2
    		IG switch ON
    		4.75 to 5.25 V
    SR2 (S38-15) - Body ground
    		V - Body ground
    		Main relay output 2
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1 V
    R2+ (S38-17) - Body ground
    		Y - Body ground
    		Main relay power 2
    		IG switch ON
    		9.1 to 13.6 V
    SLRRR- (S38-18) - Body ground
    		BR - Body ground
    		RR solenoid (-) output
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    SLARR+ (S38-19) - Body ground
    		V - Body ground
    		RR solenoid (+) output
    		IG switch ON
    Brake pedal depressed approx. 1.5 sec. after pushing IG switch ON
    		Pulse generation
    (see waveform 1)
    SLRRR+ (S38-20) - Body ground
    		R - Body ground
    		RR solenoid (+) output
    		IG switch ON
    Brake pedal depressed approx. 1.5 sec. after pushing IG switch ON
    		Pulse generation
    (see waveform 1)
    PCK2 (S38-21) - Body ground
    		L - Body ground
    		Pressure sensor check output 2
    		IG switch ON
    		4.75 to 5.25 V
    FL- (S38-22) - Body ground
    		G - Body ground
    		FL sensor (-) input
    		IG switch OFF
    		Below 1 Ω
    PFL (S38-23) - Body ground
    		R - Body ground
    		FL pressure sensor input
    		IG switch ON
    Brake pedal released
    		0.3 to 0.8 V
    MR2+ (S38-25) - Body ground
    		R - Body ground
    		Motor relay power 2
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		8.8 to Below 14 V
    SLRFL- (S38-26) - Body ground
    		L - Body ground
    		FL solenoid (-) output
    		IG switch ON
    Approx. 1.5 sec. after pushing IG switch ON
    		Below 1.5 V
    PMC2 (S38-27) - Body ground
    		W - Body ground
    		Master pressure sensor input 2
    		IG switch ON
    Brake pedal released
    		0.3 to 0.8 V
    FL+ (S38-28) - Body ground
    		R - Body ground
    		FL sensor (+) input
    		Vehicle speed input
    		Pulse generation
    (see waveform 3)
    E2 (S38-29) - Body ground
    		G - Body ground
    		Pressure sensor ground 2
    		IG switch OFF
    		Below 1 Ω
    MR2 (S38-30) - Body ground
    		G - Body ground
    		Motor relay output 2
    		IG switch ON
    Pump motor is operating
    		Below 1.5 V
    PRR (S38-31) - Body ground
    		Y - Body ground
    		RR pressure sensor input
    		IG switch ON
    Brake pedal released
    		0.3 to 0.8 V



    4. F047507E01

  4. Waveform 1

    NOTICE:
    Normal waveform is output only when BS 1 and 2 voltages are normal (10 to 14 V).

    HINT:
    1. While driving at approximately 12 mph (20 km/h).
    2. 5 V/DIV, 200 ms/DIV.
    3. Brake pedal depressed.



    5. F047507E01

  5. Waveform 2

    NOTICE:
    Normal waveform is output only when BS 1 and 2 voltages are normal (10 to 14 V).

    HINT:
    1. While driving at approximately 12 mph (20 km/h).
    2. 5 V/DIV, 200 ms/DIV.
    3. Brake pedal depressed → released



    6. F047509E01

  6. Waveform 3

    NOTICE:
    As the vehicle speed (tire rotating speed) becomes faster the cycle becomes shorter and the output voltage larger.

    HINT:
    1. 1 V/DIV, 2 ms/DIV.
    2. While driving at approximately 18 mph (30 km/h).



    7. F047510E01

  7. Waveform 4

    NOTICE:
    As the vehicle speed (tire rotating speed) becomes faster the cycle becomes shorter.

    HINT:
    1. 5 V/DIV, 50 ms/DIV.
    2. While driving at approximately 12 mph (20 km/h).



    8. F047511E01

  8. Waveform 5

    HINT:
    1. 5 V/DIV, 200 ms/DIV.
    2. IG switch ON



    9. F047511E01

  9. Waveform 6

    HINT:
    1. 5 V/DIV, 100 ms/DIV.
    2. IG switch ON



    10. F047510E01

  10. Waveform 7

    NOTICE:
    As the vehicle speed (tire rotating speed) becomes faster the cycle becomes shorter.

    HINT:
    1. 1 V/DIV, 2 ms/DIV.
    2. While driving at approximately 12 mph (20 km/h).