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Terminals Of Ecu

  1. CHECK BATTERY VOLTAGE 
    1. Measure the battery voltage.

      Voltage: 10 to 14 V 

  2. 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.
      NOTE:
      • Inspection should be performed from the back of the connector with the connector connected to the skid control ECU.
      • 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).
        Fig 1: Identifying Connector Terminals Skid Control ECU
        G04113173Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

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

      SKID CONTROL ECU 

      SKID CONTROL ECU SYMBOLS AND TERMINAL DESCRIPTION

      Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition
      GND1 (S38-1) - Body ground W-B - Body ground Skid control ECU ground Always Below 1 Ω
      R1+ (S38-2) - Body ground L-Y - Body ground Main relay power 1 IG switch on 9.1 to 13.6 V
      BS1 (S38-3) - Body ground L - Body ground Battery source 1 IG switch ON
      Approx. 1.5 sec. after turning IG switch ON      		 8.8 to 14 V
      SMC1 (S38-4) - Body ground V-W - Body ground Master cut solenoid 1 output IG switch ON Brake pedal depressed approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      CTY+ (S38-5) - Body ground W-R - Body ground Courtesy power input Driver door open --> close Approx. 5 sec. 8 to 16 V --> Below 1 V
      FRA- (S38-6) - Body ground LG-B - Body ground FR solenoid (-) output IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1.5 Ω
      FRA+ (S38-7) - Body ground LG - Body ground FR solenoid (+) output IG switch ON Brake pedal depressed approx. 1.5 sec. after turning IG switch ON Pulse generation (see  d )
      E (S38-8) - Body ground W - Body ground Pressure sensor ground IG switch OFF Below 1 Ω
      VCM (S38-9) - Body ground B - Body ground Pressure sensor power IG switch ON 4.75 to 5.25 V
      MR1 (S38-11) - Body ground Y-R - Body ground Motor relay power 1 IG switch ON Approx. 1.5 sec. after turning IG switch ON 8.8 to 14 V
      R3+ (S38-12) - Body ground L-R - Body ground Main relay output 1 IG switch ON Approx. 1.5 sec. or more after turning IG switch ON Below 1 V
      SS (S38-13) - Body ground GR - Body ground Stroke simulator cut IG switch ON Brake pedal depressed Below 1.5 V
      RLA+ (S38-15) - Body ground L - Body ground RL solenoid (+) output IG switch ON Brake pedal depressed approx. 1.5 sec. after turning IG switch ON Pulse generation (see  d )
      RLR+ (S38-16) - Body ground GR - Body ground RL solenoid (+) output IG switch ON Brake pedal depressed approx. 1.5 sec. after turning IG switch ON Pulse generation (see  d )
      FRR+ (S38-17) - Body ground P - Body ground FR solenoid (+) output IG switch ON After approx. 1.5 sec., brake pedal depressed --> released Pulse generation (see  e )
      PRL (S38-18) - Body ground W - Body ground RL pressure sensor input IG switch ON Brake pedal released 0.3 to 0.8 V
      SG1 (S38-20) - Body ground LG - Body ground Pressure sensor shield ground 1 IG switch OFF Below 1 Ω
      PAC1 (S38-21) - Body ground Y - 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- (S38-22) - Body ground O - Body ground FR sensor (-) input IG switch OFF Below 1 Ω
      PFR (S38-23) - Body ground L - Body ground FR pressure sensor input IG switch ON Brake pedal released 0.3 to 0.8 V
      R1- (S38-25) - Body ground L-Y - Body ground Motor relay output 1 IG switch ON Pump motor is operating Below 1.5 V
      RLR- (S38-26) - Body ground GR-R - Body ground RL solenoid (-) output IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      RLA- (S38-27) - Body ground Y - Body ground RL solenoid (-) output IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      MTT (S38-29) - Body ground O - Body ground Motor test input IG switch ON Pump motor is operating 3.5 V or higher
      PMC1 (S38-30) - Body ground G - Body ground Master pressure sensor input 1 IG switch ON Brake pedal released 0.3 to 0.8 V
      PCK1 (S38-31) - Body ground BR - Body ground Pressure sensor check output 1 IG switch ON Approx. 1.5 sec. after turning IG switch ON 4.75 to 5.25 V
      FR+ (S38-32) - Body ground W - Body ground FR sensor (+) input Vehicle speed input Pulse generation (see  f )
      FRR- (S38-34) - Body ground P-B - Body ground FR solenoid (-) output IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      GND3 (S39-1) - Body ground W-B - Body ground Skid control ECU ground Always Below 1 Ω
      GND2 (S39-2) - Body ground W-B - Body ground Skid control ECU ground Always Below 1 Ω
      +BI1 (S39-3) - Body ground L - Body ground Main relay power input 1 IG switch OFF 10 to 14 V
      WFSE (S39-4) - Body ground GR - Body ground Mode control signal input IG switch ON 9.1 to 13.6 V
      +BO1 (S39-5) - Body ground Y - Body ground Main relay power output 1 IG switch ON 8.8 to 14 V
      IG1 (S39-7) - Body ground Y - Body ground IG1 power IG switch ON 10 to 14 V
      RSS (S39-10) - Body ground BR - Body ground Speed sensor shield ground IG switch OFF Below 1 Ω
      BZ (S39-12) - Body ground O - Body ground Warning buzzer output IG switch ON Buzzer is operating Below 1 V
      STP (S39-14) - Body ground B - Body ground Stop light switch signal input IG switch ON Brake pedal depressed --> released 10 to 12 V --> Below 1.5 V
      CANL (S39-18) - Body ground W - Body ground CAN communication (Send and receive-) Check DTC using intelligent tester CAN communication's DTC is not output
      CANH (S39-19) - Body ground B - Body ground CAN communication (Send and receive+) Check DTC using intelligent tester CAN communication's DTC is not output
      FAIL (S39-20) - Body ground B-R - Body ground Capacitor communication (Receive) IG switch ON Approx. 1.5 sec. after turning IG switch ON Pulse generation (see  h )
      SP1 (S39-22) - Body ground BR - Body ground Speedometer output Vehicle speed input Pulse generation (see  g )
      RLO (S39-25) - Body ground P - Body ground RL speed signal output Vehicle speed output Pulse generation (see  j )
      RL- (S39-27) - Body ground G - Body ground RL sensor (-) input IG switch OFF Below 1 Ω
      ENA (S39-30) - Body ground G-R - Body ground Capacitor communication (Send) IG switch ON Approx. 1.5 sec. after turning IG switch ON Pulse generation (see  i )
      TS (S39-32) - Body ground GR - Body ground Sensor diagnosis check input IG switch ON Below 1.5 V --> 9.1 to 13.6 V
      VBZ (S39-33) - Body ground G - Body ground Warning buzzer power IG switch ON 9.1 to 13.6 V
      RL+ (S39-35) - Body ground R - Body ground RL sensor (+) input Vehicle speed input Pulse generation (see  f )
      GND5 (S40-1) - Body ground W-B - Body ground Skid control ECU ground Always Below 1 Ω
      GND4 (S40-2) - Body ground W-B - Body ground Skid control ECU ground Always Below 1 Ω
      +BO2 (S40-4) - Body ground L- Body ground Main relay power output 2 IG switch ON 8.8 to 14 V
      +BI2 (S40-5) - Body ground L-B - Body ground Main relay power input 2 IG switch OFF 10 to 14 V
      VCSK (S40-6) - Body ground W - Body ground Stroke sensor power IG switch ON 3.75 to 4.95 V
      SGSK (S40-7) - Body ground Shielded - Body ground Stroke sensor shield ground IG switch OFF Below 1 Ω
      SKG (S40-8) - Body ground R - Body ground Stroke sensor power IG switch OFF Below 1 Ω
      PKB (S40-14) - Body ground LG - Body ground Parking brake signal input Parking brake applied --> released Below 1.5 V --> 9.1 to 13.6 V
      SKS (S40-21) - Body ground G - Body ground Stroke sensor signal input 1 IG switch ON Brake pedal released 0.46 to 1.35 V
      SKS2 (S40-22) - Body ground B - Body ground Stroke sensor signal input 2 IG switch ON Brake pedal released 2.56 to 4.35 V
      RR- (S40-23) - Body ground R - Body ground RR sensor (-) input IG switch OFF Below 1 Ω
      EXI (S40-24) - Body ground GR - Body ground Cruise relay ON signal input Cruise control brake OFF --> ON Below 1 Ω --> 10 to 14 V
      RR+ (S40-31) - Body ground G - Body ground RR sensor (+) input Vehicle speed input Pulse generation (see  f )
      RRO (S40-33) - Body ground O - Body ground RR speed signal output Vehicle speed output Pulse generation (see  j )
      FLA+ (S41-1) - Body ground G-Y - Body ground FL solenoid (+) output IG switch ON Brake pedal depressed approx. 1.5 sec. after turning IG switch ON Pulse generation (see  d )
      FLA- (S41-2) - Body ground V - Body ground FL solenoid (-) output IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      SMC2 (S41-3) - Body ground V - Body ground Master cut solenoid 2 output IG switch ON Brake pedal depressed approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      IG2 (S41-5) - Body ground W - Body ground IG2 power IG switch ON 10 to 14 V
      LBL (S41-6) - Body ground B - Body ground Brake fluid level switch input Reservoir level switch OFF --> ON 4 to 4.65 V --> Below 1.5 V
      BS2 (S41-7) - Body ground G - Body ground Battery source 2 IG switch ON Approx. 1.5 sec. after turning IG switch ON 8.8 to 14 V
      FLR+ (S41-8) - Body ground L - Body ground FL solenoid (+) output IG switch ON After approx. 1.5 sec., brake pedal depressed --> released Pulse generation (see  e )
      RRA- (S41-9) - Body ground Y-R - Body ground RR solenoid (-) output IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      CR (S41-11) - Body ground G - Body ground Cruise relay output Cruise control brake OFF --> ON Below 1 V --> 10 to 14 V
      SG2 (S41-12) - Body ground Shielded - Body ground Pressure sensor shield ground 2 IG switch OFF Below 1 Ω
      FSS (S41-13) - Body ground LG - Body ground Speed sensor shield ground IG switch OFF Below 1 Ω
      Vcm2 (S41-14) - Body ground BR - Body ground Pressure sensor power 2 IG switch ON 4.75 to 5.25 V
      R4+ (S41-15) - Body ground B-R - Body ground Main relay output 2 IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1 V
      R2+ (S41-17) - Body ground G-Y - Body ground Main relay power 2 IG switch ON 9.1 to 13.6 V
      RRR- (S41-18) - Body ground G-R - Body ground RR solenoid (-) output IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      RRA+ (S41-19) - Body ground Y-G - Body ground RR solenoid (+) output IG switch ON Brake pedal depressed approx. 1.5 sec. after turning IG switch ON Pulse generation (see  d )
      RRR+ (S41-20) - Body ground G-O - Body ground RR solenoid (+) output IG switch ON Brake pedal depressed approx. 1.5 sec. after turning IG switch ON Pulse generation (see  d )
      PCK2 (S41-21) - Body ground G - Body ground Pressure sensor check output 2 IG switch ON 4.75 to 5.25 V
      FL- (S41-22) - Body ground R - Body ground FL sensor (-) input IG switch OFF Below 1 Ω
      PFL (S41-23) - Body ground R - Body ground FL pressure sensor input IG switch ON Brake pedal released 0.3 to 0.8 V
      MR2+ (S41-25) - Body ground Y-B - Body ground Motor relay power 2 IG switch ON Approx. 1.5 sec. after turning IG switch ON 8.8 to Below 14 V
      FLR- (S41-26) - Body ground L-W - Body ground FL solenoid (-) output IG switch ON Approx. 1.5 sec. after turning IG switch ON Below 1.5 V
      PMC2 (S41-27) - Body ground O - Body ground Master pressure sensor input 2 IG switch ON Brake pedal released 0.3 to 0.8 V
      FL+ (S41-28) - Body ground G - Body ground FL sensor (+) input Vehicle speed input Pulse generation (see  f )
      E2 (S41-29) - Body ground Y - Body ground Pressure sensor ground 2 IG switch OFF Below 1 Ω
      R2- (S41-30) - Body ground L-R - Body ground Motor relay output 2 IG switch ON Pump motor is operating Below 1.5 V
      PRR (S41-31) - Body ground W-G - Body ground RR pressure sensor input IG switch ON Brake pedal released 0.3 to 0.8 V
    4. Waveform 1
      NOTE: Normal waveform is output only when BS 1 and 2 voltages are normal (10 to 14 V).

      HINT:

      • While driving at approximately 12 mph (20 km/h).
      • 5 V/DIV, 200 ms/DIV.
      • Brake pedal depressed.
        Fig 2: Signal Waveform 1
        G04113174Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Waveform 2
      NOTE: Normal waveform is output only when BS 1 and 2 voltages are normal (10 to 14 V).

      HINT:

      • While driving at approximately 12 mph (20 km/h).
      • 5 V/DIV, 200 ms/DIV.
      • Brake pedal depressed --> released
        Fig 3: Signal Waveform 2
        G04113175Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. Waveform 3
      NOTE: As the vehicle speed (tire rotating speed) becomes faster, the cycle becomes shorter and the output voltage larger.

      HINT:

      • 1 V/DIV, 2 ms/DIV.
      • While driving at approximately 18 mph (30 km/h).
        Fig 4: Signal Waveform 3
        G04113176Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    7. Waveform 4
      NOTE: As the vehicle speed (tire rotating speed) becomes faster, the cycle becomes shorter.

      HINT:

      • 5 V/DIV, 50 ms/DIV.
      • While driving at approximately 12 mph (20 km/h).
        Fig 5: Signal Waveform 4
        G04113177Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    8. Waveform 5

      HINT:

      • 5 V/DIV, 200 ms/DIV.
      • IG switch ON
        Fig 6: Signal Waveform 5
        G04113178Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    9. Waveform 6

      HINT:

      • 5 V/DIV, 100 ms/DIV.
      • IG switch ON
        Fig 7: Signal Waveform 6
        G04113179Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    10. Waveform 7
      NOTE: As the vehicle speed (tire rotating speed) becomes faster, the cycle becomes shorter.

      HINT:

      • 1 V/DIV, 2 ms/DIV.
      • While driving at approximately 12 mph (20 km/h).
        Fig 8: Signal Waveform 7
        G04113180Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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