ELECTRONICALLY CONTROLLED BRAKE SYSTEM TERMINALS OF ECU


  1. SKID CONTROL ECU ASSEMBLY

    B003YT1C05
    *a

    Component without harness connected

    (Skid Control ECU Assembly)

    		 - -
    Terminal No. (Symbol) Terminal Description
    A24-1 (GND) Skid control ECU assembly ground
    A24-2 - (Not used)
    A24-3 (FRR-) Front reduction linear solenoid RH (-) output
    A24-4 (FRR+) Front reduction linear solenoid RH (+) output
    A24-5 (SMC1) Master cut solenoid 1 output
    A24-6 - (Not used)
    A24-7 - (Not used)
    A24-8 (ENA) Brake control power supply assembly signal output
    A24-9 (PCK1) Pressure sensor 1 stuck check output
    A24-10 (RL-) Rear speed sensor LH input
    A24-11 (RL+) Rear speed sensor LH power supply output
    A24-12 (SG1) Pressure sensor 1 shield ground
    A24-13 (SG3) Pressure sensor 1 shield ground
    A24-14 (PMC1) Master cylinder pressure sensor 1 signal input
    A24-15 (FR-) Front speed sensor RH input
    A24-16 (FR+) Front speed sensor RH power supply output
    A24-17 (FRA+) Front addition linear solenoid RH (+) output
    A24-18 (FRA-) Front addition linear solenoid RH (-) output
    A24-19 (RLA+) Rear addition linear solenoid LH (+) output
    A24-20 (RLA-) Rear addition linear solenoid LH (-) output
    A24-21 - (Not used)
    A24-22 - (Not used)
    A24-23 (SP1) Speedometer signal output
    A24-24 (STP2) Stop light signal input
    A24-25 (CTY) Front door courtesy light switch assembly input (for driver side)
    A24-26 (PAC1) Accumulator pressure sensor signal input
    A24-27 (VCM) Pressure sensor 1 power supply output
    A24-28 (E) Pressure sensor 1 ground
    A24-29 (+BI3) +B power source 3
    A24-30 - (Not used)
    A24-31 - (Not used)
    A24-32 (BS01) Master cut solenoid 1 power supply output
    A24-33 (RLR-) Rear reduction linear solenoid LH (-) output
    A24-34 (RLR+) Rear reduction linear solenoid LH (+) output
    A24-35 (MR1) ABS motor relay 1 power supply output
    A24-36 (R1-) ABS motor relay 1 output
    A24-37 (MTT) ABS motor relay test input
    A24-38 (CBI1) Brake control power supply assembly power supply input 1
    A24-39 (CSW) VSC OFF switch (Combination switch assembly) input
    A24-40 - (Not used)
    A24-41 - (Not used)
    A24-42 (PRL) Rear wheel cylinder pressure sensor LH signal input
    A24-43 (+BI1) +B power source 1
    A24-44 (PFR) Front wheel cylinder pressure sensor RH signal input
    A24-45 (LBL) Brake fluid level warning switch (Brake master cylinder reservoir assembly) input
    A24-46 (IG1) IG1 power source input
    A25-1 (GND4) Skid control ECU assembly ground 4
    A25-2 (EXO) Stop light signal output (for emergency brake signal)
    A25-3 (FLR-) Front reduction linear solenoid LH (-) output
    A25-4 (FLR+) Front reduction linear solenoid LH (+) output
    A25-5 No pin
    A25-6 (SMC2) Master cut solenoid 2 output
    A25-7 (PCK2) Pressure sensor 2 stuck check output
    A25-8 (CANL) CAN communication line 3
    A25-9 (CANH) CAN communication line 3
    A25-10 (RR-) Rear speed sensor RH input
    A25-11 (RR+) Rear speed sensor RH power supply output
    A25-12 No pin
    A25-13 - (Not used)
    A25-14 (PMC2) Master cylinder pressure sensor 2 signal input
    A25-15 (FL-) Front speed sensor LH input
    A25-16 (FL+) Front speed sensor LH power supply output
    A25-17 (FLA+) Front addition linear solenoid LH (+) output
    A25-18 (FLA-) Front addition linear solenoid LH (-) output
    A25-19 No pin
    A25-20 (RRA+) Rear addition linear solenoid RH (+) output
    A25-21 (RRA-) Rear addition linear solenoid RH (-) output
    A25-22 (+BI4) +B power source 4
    A25-23 - (Not used)
    A25-24 - (Not used)
    A25-25 (STP) Stop light switch assembly input
    A25-26 No pin
    A25-27 (SG2) Pressure sensor 2 shield ground
    A25-28 (VCM2) Pressure sensor 2 power supply output
    A25-29 (CA1L) CAN communication line 1
    A25-30 (CA1H) CAN communication line 1
    A25-31 (STPO) Stop light signal output
    A25-32 (BS02) Master cut solenoid 2 power supply output
    A25-33 (RRR-) Rear reduction linear solenoid RH (-) output
    A25-34 (RRR+) Rear reduction linear solenoid RH (+) output
    A25-35 No pin
    A25-36 (MR2) ABS motor relay 2 power supply output
    A25-37 (R2-) ABS motor relay 2 output
    A25-38 (+BI2) +B power source 2
    A25-39 - (Not used)
    A25-40 (CBI2) Brake control power supply assembly power supply input 2
    A25-41 (FAIL) Brake control power supply assembly signal input
    A25-42 No pin
    A25-43 (PRR) Rear wheel cylinder pressure sensor RH signal input
    A25-44 (E2) Pressure sensor 2 ground
    A25-45 (PFL) Front wheel cylinder pressure sensor LH signal input
    A25-46 (IG2) IG2 power source input
    A26-1 (SKS2) Brake pedal stroke sensor assembly 2 signal input
    A26-2 - (Not used)
    A26-3 (SKS) Brake pedal stroke sensor assembly 1 signal input
    A26-4 (SKG) Brake pedal stroke sensor assembly ground
    A26-5 (VCSK) Brake pedal stroke sensor assembly power supply output

  2. TERMINAL INSPECTION


    1. Disconnect the A24 and A25 skid control ECU assembly connectors.

      B003YBMC05
      *a

      Front view of wire harness connector

      (to Skid Control ECU Assembly)

      		 - -

    2. Measure the voltage or resistance according to the value(s) in the table below.

      Tech Tips

      Voltage cannot be measured with the connector connected to the skid control ECU assembly as the connector is watertight.

      Standard
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A24-1 (GND) - Body ground W-B - Body ground Skid control ECU assembly ground Always Below 1 Ω
      A24-24 (STP2) - Body ground B - Body ground Stop light signal input

      Stop light switch assembly on → off

      (Brake pedal depressed → released)

      		 11 to 14 V → Below 1.5 V
      A24-25 (CTY) - Body ground V - Body ground Front door courtesy light switch assembly input (for driver side) Driver door close → open Pulse generation (see waveform) → Below 1 V
      A24-29 (+BI3) - Body ground GR - Body ground +B power source 3 Always 11 to 14 V
      A24-39 (CSW) - Body ground R - Body ground VSC OFF switch (Combination switch assembly) input VSC OFF switch (Combination switch assembly) held on → off (Released) Below 50 Ω → 10 kΩ or higher
      A24-43 (+BI1) - Body ground B - Body ground +B power source 1 Always 11 to 14 V
      A24-45 (LBL) - Body ground B - Body ground Brake fluid level warning switch (Brake master cylinder reservoir assembly) input

      Brake fluid level warning switch (Brake master cylinder reservoir assembly) off → on

      (Float up → down)

      		 1.84 to 2.16 kΩ → Below 1 Ω
      A24-46 (IG1) - Body ground B - Body ground IG1 power source input Power switch on (IG) 11 to 14 V
      A25-1 (GND4) - Body ground W-B - Body ground Skid control ECU assembly ground 4 Always Below 1 Ω
      A25-22 (+BI4) - Body ground GR - Body ground +B power source 4 Always 11 to 14 V
      A25-25 (STP) - Body ground R - Body ground Stop light switch assembly input

      Stop light switch on → off

      (Brake pedal depressed → released)

      		 11 to 14 V → Below 1.5 V
      A25-38 (+BI2) - Body ground G - Body ground +B power source 2 Always 11 to 14 V
      A25-46 (IG2) - Body ground G - Body ground IG2 power source input Power switch on (IG) 11 to 14 V

      1. B003YAKC02
        *a Driver door close
        *b Driver door open

        Waveform

        Item Content
        Tester Connection A24-25 (CTY) - Body ground
        Tool Setting 5 V/DIV., 10 ms./DIV.
        Vehicle Condition Driver door close → open