Lexus IS250 · Service Manual SECURITIES

TERMINALS OF ECU

System information


CHECK MAIN BODY ECU RH (COWL SIDE J/B RH)

  1. Disconnect the main body ECU RH (cowl side J/B RH) connectors.
    B106792E04

  2. Measure the resistance and voltage of the wire harness side connectors.

    Symbols (Terminal No.)
    		 Wiring Color
    		 Terminal Description
    		 Condition
    		 Specified Condition
    PCTY (J75-23) - Body ground
    		 B*1 - Body ground
    		 Passenger side courtesy light switch input
    		 Passenger side door CLOSED (OFF) → OPEN (ON)
    		 10 kΩ or higher → Below 1 Ω
    PCTY (J75-23) - Body ground
    		 V*2 - Body ground
    		 Passenger side courtesy light switch input
    		 Passenger side door CLOSED (OFF) → OPEN (ON)
    		 10 kΩ or higher → Below 1 Ω
    LGCY (J75-25) - Body ground
    		 L - Body ground
    		 Luggage compartment door courtesy light switch input
    		 Luggage compartment door CLOSED (OFF) → OPEN (ON)
    		 10 kΩ or higher → Below 1 Ω
    DCTY (P1-14) - Body ground
    		 W - Body ground
    		 Driver side door courtesy light switch input
    		 Driver side door CLOSED (OFF) → OPEN (ON)
    		 10 kΩ or higher → Below 1 Ω
    RCTY (P1-16) - Body ground
    		 O - Body ground
    		 Rear courtesy light switch RH input
    		 Rear door RH CLOSED (OFF) → OPEN (ON)
    		 10 kΩ or higher → Below 1 Ω
    GND2 (RA-5) - Body ground
    		 W-B - Body ground
    		 Ground
    		 Always
    		 Below 1 Ω
    LCTY (RA-11) - Body ground
    		 BR - Body ground
    		 Rear courtesy light switch LH input
    		 Rear door LH CLOSED (OFF) → OPEN (ON)
    		 10 kΩ or higher → Below 1 Ω
    ALTB (RM-1) - Body ground
    		 B - Body ground
    		 +B (power generator system) power supply
    		 Always
    		 10 to 14 V
    GND2 (RD-7) - Body ground
    		 W-B - Body ground
    		 Ground
    		 Always
    		 Below 1 Ω
    BECU (RK-5) - Body ground
    		 G-R - Body ground
    		 +B power supply
    		 Always
    		 10 to 14 V
    ACC (RM-1) - Body ground
    		 B - Body ground
    		 Ignition power supply (ACC signal)
    		 Engine switch on (ACC) → off
    		 10 to 14 V → Below 1 V
    IG (RM-1) - Body ground
    		 B - Body ground
    		 Ignition power supply (IG signal)
    		 Engine switch on (ACC) → off
    		 10 to 14 V → Below 1 V
    BATB (RN-1) - Body ground
    		 R - Body ground
    		 +B (power battery system) power supply
    		 Always
    		 10 to 14 V

    HINT:
    1. *1: LHD
    2. *2: RHD

    If the result is not as specified, there may be a malfunction on the wire harness side.

  3. Reconnect the main body ECU RH (cowl side J/B RH) connectors.

  4. Measure the voltage of the wire harness side connectors.

    Symbols (Terminal No.)
    		 Wiring Color
    		 Terminal Description
    		 Condition
    		 Specified Condition
    SH (A36-1) - Body ground
    		 W- Body ground
    		 Security horn drive
    		 Security horn is sounding (Theft deterrent system is in alarm sounding state)
    		 Pulse generation
    0 V ← → 12 V
    HAZ (J74-2) - Body ground
    		 Y - Body ground
    		 Hazard warning light signal
    		 Hazard warning lights are blinking (Theft deterrent system is in alarm sounding state)
    		 Pulse generation
    0 V ← → 12 V
    IND (J74-24) - Body ground
    		 LG - Body ground
    		 Security indicator output
    		 Security indicator light up
    (It lights up only for 30 sec. in alarm sounding state. It flashes when immobiliser is operating.)
    		 3 to 6 V
    S+B (J75-11) - Body ground
    		 G - Body ground
    		 Intrusion sensor power supply
    		 Arming preparation state or armed state
    		 10 to 14 V
    S+B (J75-11) - Body ground
    		 G - Body ground
    		 Intrusion sensor power supply
    		 Disarmed state
    		 Below 1 V
    ISIF (J75-13) - Body ground
    		 SB - Body ground
    		 Intrusion sensor signal input
    		 No moving object detected by sensor
    		 10 to 14 V
    ISIF (J75-13) - Body ground
    		 SB - Body ground
    		 Intrusion sensor signal input
    		 Moving object detected by sensor during arming preparation state or armed state
    		 Pulse generation


CHECK ENGINE ROOM NO. 2 R/B ASSEMBLY (FRONT CONTROLLER)

  1. Disconnect the 2G R/B connector.
    E108357E01

  2. Measure the resistance between each terminal of the wire harness connector and body ground.

    Terminal No.
    		 Wiring Color
    		 Terminal Description
    		 Condition
    		 Specified Condition
    2G-3 - Body ground
    		 W-L - Body ground
    		 Engine hood courtesy switch
    		 Engine hood CLOSED (OFF) → OPEN (ON)
    		 10 kΩ or higher → Below 1 Ω
    If the result is not as specified, there may be a malfunction on the wire harness side.

  3. Reconnect the and 2G R/B connector.

  4. Measure the voltage between each terminal of the connector and body ground.

    Terminal No.
    		 Wiring Color
    		 Terminal Description
    		 Condition
    		 Specified Condition
    2G-1 - Body ground
    		 B - Body ground
    		 Vehicle horn drive
    		 Vehicle horn is sounding
    (Theft deterrent system is in alarm sounding state)
    		 Pulse generation
    (0 V ← → 12 V)
    2G-2 - Body ground
    		 B-R - Body ground
    		 Vehicle horn drive
    		 Vehicle horn is sounding
    (Theft deterrent system is in alarm sounding state)
    		 Pulse generation
    (0 V ← → 12 V)

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