ELECTRONICALLY CONTROLLED BRAKE SYSTEM TERMINALS OF ECU


  1. CHECK AUXILIARY BATTERY VOLTAGE


    1. Check the auxiliary battery voltage.

    2. SKID CONTROL ECU INSPECTION


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

      2. Connect the intelligent tester to the DLC3, and check the communication condition with the skid control ECU.

      3. Using an oscilloscope, check the pulse generated between each terminal or between each terminal and 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 brake warning light / yellow (minor malfunction) comes on (malfunctioning).

        A01NF9EE08
      3. Text in Illustration
      *1

      Component without harness connected

      (Skid Control ECU)

      		 - -

Tech Tips

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

Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
A89-1 (GND) - Body ground W-B - Body ground Skid control ECU ground 1 Power switch off Below 1 Ω
A89-2 (BS03) - Body ground L - Body ground Stroke simulator cut solenoid power supply output Approx. 1.5 seconds after turning power switch on (IG) 8.8 to 14 V
A89-3 (BS01) - Body ground G - Body ground Master cut solenoid 1 power supply output Approx. 1.5 seconds after turning power switch on (IG) 8.8 to 14 V
A89-4 (SMC1) - Body ground W - Body ground Master cut solenoid 1 output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A89-5 (SS) - Body ground GR - Body ground Stroke simulator cut solenoid output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A89-6 (FRR+) - Body ground P - Body ground Front reduction solenoid (+) RH output Power switch on (IG), after approx. 1.5 seconds brake pedal depressed → released

Pulse generation

(see waveform 2)
A89-7 (FRR-) - Body ground B - Body ground Front reduction solenoid (-) RH output Approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A89-8 (E) - Body ground W - Body ground Pressure sensor 1 ground Power switch off Below 1 Ω
A89-9 (VCM) - Body ground B - Body ground Pressure sensor 1 power supply output Power switch on (IG) 4.75 to 5.25 V
A89-10 (SG1) - Body ground Shielded - Body ground Pressure sensor 1 shield ground Power switch off Below 1 Ω
A89-11 (MR1) - Body ground Y - Body ground ABS motor relay 1 power supply output Approx. 1.5 seconds after turning power switch on (IG) 8.8 to 14 V
A89-12 (SG3) - Body ground Shielded - Body ground Pressure sensor 3 shield ground Power switch off Below 1 Ω
A89-13 (GS1) - Body ground Shielded - Body ground Front speed sensor RH shield ground Power switch off Below 1 Ω
A89-14 (CTY) - Body ground R - Body ground Courtesy power source input Driver door close → open 8 to 16 V → Below 1 V
A89-16 (RLR-) - Body ground R - Body ground Rear reduction solenoid (-) LH output Approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A89-17 (RLR+) - Body ground GR - Body ground Rear reduction solenoid (+) LH output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG)

Pulse generation

(see waveform 1)
A89-18 (PRL) - Body ground W - Body ground Rear wheel cylinder pressure sensor LH input Power switch on (IG), brake pedal released 0.3 to 0.8 V
A89-21 (PAC1) - Body ground Y - Body ground Accumulator pressure sensor input Power switch on (IG), after pump motor operates and stops by pedal operation 3 to 4.7 V
A89-22 (FR+) - Body ground B - Body ground Front speed sensor (+) RH power supply output Vehicle speed input 8 to 15 V
A89-23 (FR-) - Body ground W - Body ground Front speed sensor (-) RH input Power switch off

Pulse generation

(see waveform 3)
A89-24 (R1-) - Body ground V - Body ground ABS motor relay 1 output Power switch on (IG), pump motor in operation Below 1.5 V
A89-26 (RLA+) - Body ground L - Body ground Rear addition solenoid (+) LH output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG)

Pulse generation

(see waveform 1)
A89-27 (RLA-) - Body ground Y - Body ground Rear addition solenoid (-) LH output Approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A89-29 (MTT) - Body ground BE - Body ground Motor relay test input Power switch on (IG), pump motor in operation 5 V or higher
A89-30 (PMC1) - Body ground G - Body ground Master cylinder pressure sensor 1 input Power switch on (IG), brake pedal released 0.3 to 0.8 V
A89-31 (PCK1) - Body ground BR - Body ground Pressure sensor 1 stuck check output Approx. 1.5 seconds after turning power switch on (IG) 4.75 to 5.25 V
A89-32 (PFR) - Body ground L - Body ground Front wheel cylinder pressure sensor RH input Power switch on (IG), brake pedal released 0.3 to 0.8 V
A89-33 (FRA-) - Body ground B - Body ground Front addition solenoid (-) RH output Approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A89-34 (FRA+) - Body ground LG - Body ground Front addition solenoid (+) RH output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG)

Pulse generation

(see waveform 1)
A90-1 (GND3) - Body ground W-B - Body ground Skid control ECU ground 3 Power switch off Below 1 Ω
A90-2 (IG1) - Body ground BE - Body ground IG1 power source input Power switch on (IG) 11 to 15 V
A90-3 (GND2) - Body ground W-B - Body ground Skid control ECU ground 2 Power switch off Below 1 Ω
A90-4 (+BI1) - Body ground L - Body ground +B power supply 1 Power switch off 11 to 15 V
A90-5 (+BI3) - Body ground G - Body ground +B power supply 3 Power switch off 11 to 15 V
A90-6 (LBL) - Body ground BR - Body ground Brake fluid level warning switch input Brake fluid level warning switch OFF → ON

4 to 8 V

→ Below 1.5 V
A90-7 (CBI1) - Body ground GR - Body ground Capacitor 1 power supply input Power switch on (IG) 8.8 to 14 V
A90-8 (CA1H) - Body ground R - Body ground

CAN communication line

(CAN No. 1 bus)

 Check DTC using the intelligent tester CAN communication's DTC is not output
A90-9 (CA1L) - Body ground W - Body ground

CAN communication line

(CAN No. 1 bus)

 Check DTC using the intelligent tester CAN communication's DTC is not output
A90-10 (CA2H) - Body ground B - Body ground

CAN communication line

(Power management bus)

 Check DTC using the intelligent tester CAN communication's DTC is not output
A90-11 (CA2L) - Body ground W - Body ground

CAN communication line

(Power management bus)

 Check DTC using the intelligent tester CAN communication's DTC is not output
A90-12 (BZ) - Body ground BE - Body ground Skid control buzzer output Power switch on (IG), buzzer in operation Below 1 V
A90-13 (VBZ) - Body ground LG - Body ground Skid control buzzer power source output Power switch on (IG) 9.1 to 14 V
A90-14 (STP2) - Body ground V - Body ground Stop light control relay input

Stop light switch ON → OFF

(Brake pedal depressed → released)

10 to 15 V

→ Below 1.5 V
A90-17 (GS2) - Body ground Shielded - Body ground Rear speed sensor LH shield ground Power switch off Below 1 Ω
A90-19 (CSW) - Body ground B - Body ground VSC OFF switch input VSC OFF switch held ON → OFF (Released) Below 1 Ω → 10 kΩ or higher
A90-20 (ENA) - Body ground R - Body ground Capacitor output Approx. 1.5 seconds after turning power switch on (IG)

Pulse generation

(see waveform 6)
A90-22 (SP1) - Body ground G - Body ground Speedometer output Vehicle speed input

Pulse generation

(see waveform 4)
A90-34 (RL+) - Body ground W - Body ground Rear speed sensor (+) LH power supply output Vehicle speed input 8 to 15 V
A90-35 (RL-) - Body ground B - Body ground Rear speed sensor (-) LH input Power switch off

Pulse generation

(see waveform 3)
A91-1 (GND5) - Body ground W-B - Body ground Skid control ECU ground 5 Power switch off Below 1 Ω
A91-2 (CBI2) - Body ground W - Body ground Capacitor 2 power supply input Power switch on (IG) 8.8 to 14 V
A91-3 (GND4) - Body ground W-B - Body ground Skid control ECU ground 4 Power switch off Below 1 Ω
A91-4 (STPO) - Body ground V - Body ground Stop light control relay output (ACC) Power switch on (IG) 11 to 15 V
A91-5 (IG2) - Body ground P - Body ground IG2 power source input Power switch on (IG) 11 to 15 V
A91-7 (SGSK) - Body ground Shielded - Body ground Stroke sensor shield ground Power switch off Below 1 Ω
A91-8 (SKG) - Body ground R - Body ground Stroke sensor ground Power switch off Below 1 Ω
A91-10 (VCSK) - Body ground W - Body ground Stroke sensor power supply output Power switch on (IG) 3.75 to 4.95 V
A91-11 (FSS) - Body ground Shielded - Body ground Front speed sensor LH shield ground Power switch off Below 1 Ω
A91-12 (CANL) - Body ground W - Body ground

CAN communication line

(CAN No. 3 bus)

 Check DTC using the intelligent tester CAN communication's DTC is not output
A91-13 (CANH) - Body ground B - Body ground

CAN communication line

(CAN No. 3 bus)

 Check DTC using the intelligent tester CAN communication's DTC is not output
A91-16 (STP1) - Body ground B - Body ground Stop light switch input

Stop light switch ON → OFF

(Brake pedal depressed → released)

 10 to 15 V → Below 1.5 V
A91-20 (SKS) - Body ground G - Body ground Stroke sensor 1 input Power switch on (IG), brake pedal released 0.46 to 1.35 V
A91-22 (SKS2) - Body ground B - Body ground Stroke sensor 2 input Power switch on (IG), brake pedal released 2.56 to 4.35 V
A91-25 (TS) - Body ground LG - Body ground Sensor check input Power switch on (IG), connect terminals TS and CG of the DLC3 → disconnect Below 1.5 V → 9.1 to 14 V
A91-30 (FAIL) - Body ground G - Body ground Capacitor input Approx. 1.5 seconds after turning power switch on (IG)

Pulse generation

(see waveform 5)
A91-31 (FL+) - Body ground B - Body ground Front speed sensor (+) LH power supply output Vehicle speed input 8 to 15 V
A91-32 (FL-) - Body ground W - Body ground Front speed sensor (-) LH input Power switch off

Pulse generation

(see waveform 3)
A92-1 (RRR-) - Body ground P - Body ground Rear reduction solenoid (-) RH output Approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A92-2 (RRR+) - Body ground BE - Body ground Rear reduction solenoid (+) RH output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG)

Pulse generation

(see waveform 1)
A92-3 (GND6) - Body ground W-B - Body ground Skid control ECU ground 6 Power switch off Below 1 Ω
A92-4 (SMC2) - Body ground V - Body ground Master cut solenoid 2 output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A92-5 (+BI2) - Body ground B - Body ground +B power supply 2 Power switch off 11 to 15 V
A92-6 (+BI4) - Body ground R - Body ground +B power supply 4 Power switch off 11 to 15 V
A92-7 (BS02) - Body ground L - Body ground Master cut solenoid 2 power supply output Approx. 1.5 seconds after turning power switch on (IG) 8.8 to 14 V
A92-8 (FLR+) - Body ground L - Body ground Front reduction solenoid (+) LH output Power switch on (IG), after approx. 1.5 seconds, brake pedal depressed → released

Pulse generation

(see waveform 2)
A92-9 (FLR-) - Body ground LG - Body ground Front reduction solenoid (-) LH output Approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A92-10 (SG2) - Body ground Shielded - Body ground Pressure sensor 2 shield ground Power switch off Below 1 Ω
A92-11 (EX0)*1 - Body ground R - Body ground Stop light control relay output (ESS) Power switch on (IG) 10 to 14 V
A92-12 (RSS) - Body ground Shielded - Body ground Rear speed sensor RH shield ground Power switch off Below 1 Ω
A92-14 (R2-) - Body ground G - Body ground ABS motor relay 2 output Power switch on (IG), pump motor in operation Below 1.5 V
A92-15 (E2) - Body ground Y - Body ground Pressure sensor 2 ground Power switch off Below 1 Ω
A92-16 (VCM2) - Body ground BR - Body ground Pressure sensor 2 power supply output Power switch on (IG) 4.75 to 5.25 V
A92-17 (MR2) - Body ground B - Body ground ABS motor relay 2 power supply output Approx. 1.5 seconds after turning power switch on (IG) 8.8 to 14 V
A92-18 (FLA-) - Body ground V - Body ground Front addition solenoid (-) LH output Approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A92-19 (FLA+) - Body ground P - Body ground Front addition solenoid (+) LH output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG)

Pulse generation

(see waveform 1)
A92-21 (RR-) - Body ground B - Body ground Rear speed sensor (-) RH input Power switch off

Pulse generation

(see waveform 3)
A92-22 (RR+) - Body ground W - Body ground Rear speed sensor (+) RH power supply output Vehicle speed input 8 to 15 V
A92-23 (PFL) - Body ground R - Body ground Front wheel cylinder pressure sensor LH input Power switch on (IG), brake pedal released 0.3 to 0.8 V
A92-24 (PRR) - Body ground W - Body ground Rear wheel cylinder pressure sensor RH input Power switch on (IG), brake pedal released 0.3 to 0.8 V
A92-26 (RRA+) - Body ground G - Body ground Rear addition solenoid (+) RH output Brake pedal depressed approx. 1.5 seconds after turning power switch on (IG)

Pulse generation

(see waveform 1)
A92-27 (RRA-) - Body ground R - Body ground Rear addition solenoid (-) RH output Approx. 1.5 seconds after turning power switch on (IG) Below 1.5 V
A92-28 (PMC2) - Body ground L - Body ground Master cylinder pressure sensor 2 input Power switch on (IG), brake pedal released 0.3 to 0.8 V
A92-29 (PCK2) - Body ground G - Body ground Pressure sensor 2 stuck check output Power switch on (IG) 4.75 to 5.25 V

*1: w/ Emergency Brake Signal

  • A01NHDRE01

    Waveform 1 (Reference): Using an oscilloscope:

    Item Condition
    Tool setting 5 V/DIV., 50 ms./DIV.
    Vehicle condition Brake pedal depressed

    Tech Tips

    Normal waveform is output only when +BI voltage is normal (11 to 14 V).

  • A01NHDRE01

    Waveform 2 (Reference): Using an oscilloscope:

    Item Condition
    Tool setting 5 V/DIV., 50 ms./DIV.
    Vehicle condition Brake pedal depressed → released

    Tech Tips

    Normal waveform is output only when +BI voltage is normal (11 to 14 V).

  • A01NG2OE01

    Waveform 3 (Reference): Using an oscilloscope:

    Item Condition
    Tool setting 0.5 V/DIV., 2 ms./DIV.
    Vehicle condition While driving at approximately 30 km/h (18 mph)

    Tech Tips

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

  • A01NDX7E01

    Waveform 4 (Reference): Using an oscilloscope:

    Item Condition
    Tool setting 5 V/DIV., 50 ms./DIV.
    Vehicle condition While driving at approximately 20 km/h (12 mph)

    Tech Tips

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

  • A01NHJZE01

    Waveform 5 (Reference): Using an oscilloscope:

    Item Condition
    Tool setting 5 V/DIV., 200 ms./DIV.
    Vehicle condition Turn the power switch on (READY)
  • A01NHJZE01

    Waveform 6 (Reference): Using an oscilloscope:

    Item Condition
    Tool setting 2 V/DIV., 50 ms./DIV.
    Vehicle condition Turn the power switch on (READY)