LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2005 >> LX 470 >> Repair and Diagnosis >> Electrical >> Body Electrical >> Power Source >> Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Power Source: Inspection

  1. INSPECT ENGINE ROOM RELAY BLOCK CIRCUIT 
    Fig 1: Identifying Engine Room Relay Block
    G02994055Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 2: Identifying Engine Room Relay Block (Back Side)
    G02994056Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 3: Engine Room Relay Block Inner Circuit (1 Of 2)
    G02994057Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 4: Engine Room Relay Block Inner Circuit (2 Of 2)
    G02994058Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the fuse from the relay block and inspect the connector on the relay block side.
      ENGINE ROOM RELAY BLOCK FUSE REFERENCE

      Fuse Tester connection Condition Specified condition
      TOWING 1 - Ground Always Battery positive voltage
      MIR HTR 3 - Ground Always Battery positive voltage
      RR HTR 5 - Ground Always Battery positive voltage
      HAZ-TRN 7 - Ground Always Battery positive voltage
      ALT-S 9 - Ground Always Battery positive voltage
      NV-IR 13-Ground Always Battery positive voltage
      FRFOG 13-Ground Always Battery positive voltage
      TOWING BRK 15 - Ground Always Battery positive voltage
      HEADCLNER 17 - Ground Ignition switch ON Battery positive voltage
      FR-IG 19-Ground Ignition switch ON Battery positive voltage
      PANEL 21 - Ground Light control switch HEAD or TAIL Battery positive voltage
      TOWING TAIL 23 - Ground Light control switch HEAD or TAIL Battery positive voltage
      TAIL 25 - Ground Light control switch HEAD or TAIL Battery positive voltage
      BAT 29 - Ground Always Battery positive voltage
      TEL 31 - Ground Always Battery positive voltage
      AMP 33 - Ground Always Battery positive voltage
      EFI or ECD NO.1 35 - Ground Always Battery positive voltage
      AM2 37 - Ground Always Battery positive voltage
      ETCS 39 - Ground Always Battery positive voltage
      HORN 41 - Ground Always Battery positive voltage
      HEAD LH-UPR 51 - Ground Light control switch HI or Flash Battery positive voltage
      HEAD RH-UPR 49 - Ground Light control switch HI or Flash Battery positive voltage
      HEAD LH-LWR 47 - Ground Light control switch HEAD Battery positive voltage
      HEAD RH-LWR 45 - Ground Light control switch HEAD Battery positive voltage
      ST1 1 - Ground Always Battery positive voltage
      AHC 1 - Ground Always Battery positive voltage
      ABS NO.1 1 - Ground Always Battery positive voltage
      ABS NO.2 1 - Ground Always Battery positive voltage
      STARTER 1 - Ground Always Battery positive voltage

      If the circuit is not as specified, inspect the circuits connected to other parts.

    2. Remove the relay from the relay block and inspect the connector on the relay block side.
      ENGINE ROOM RELAY BLOCK RELAY REFERENCE

      Relay Tester connection Condition Specified condition
      AHC 1 - Ground Ignition switch ON Battery positive voltage
      ABS SOL 1 - Ground Ignition switch ON Battery positive voltage
      ABS MTR1 1 - Ground Always Battery positive voltage
      ABS MTR2 1 - Ground Ignition switch ON Battery positive voltage
      STARTER 5 - Ground Always Continuity
      STARTER 2 - Ground Ignition switch ON Battery positive voltage
      EFI or ECD 3 - Ground Always Battery positive voltage
      C/OPN 5 - Ground Always Battery positive voltage
      C/OPN - Ground Ignition switch ON Continuity
      F/P PUMP 2 - Ground Ignition switch ON Battery positive voltage
      F/P PUMP 3 - Ground Ignition switch ON Continuity
      HTR 5 - Ground Always Battery positive voltage
      HTR 1 - Ground Ignition switch ON Continuity

      If the circuit is not as specified, inspect the circuits connected to other parts.

    3. Inspect Engine Room Relay Block Inner Circuit:

      Inspect the connector on the relay block side.

    HINT:

    Remove the relay block from the vehicle.

    RELAY BLOCK SIDE CONNECTOR

    Relay Tester connection Condition Specified condition
    IG1 NO.1 50(1B)-40(1B) Always Continuity
    IG1 NO.1 50(1B)-39(1B) Always Continuity
    IG1 NO.1 50(1B)-45(1B) Always Continuity
    IG1 NO.1 50(1B)-56(1B) Always Continuity
    IG1 NO.1 50(1B)-55(1B) Always Continuity
    IG1 NO.1 50(1B)-44(1B) Always Continuity
    IG1 NO.1 50(1B)-43(1B) Always Continuity
    IG1 NO.1 50(1B)-41 (1B) Always Continuity
    IG1 NO.1 50(1B)-42(1B) Always Continuity
    IG1 NO.1 2(1C) -47(1B) Apply B+ between terminals 50 (1B) and 40 (1B). Continuity
    IG1 NO.1 2(1C) -60(1 A) Apply B+ between terminals 50 (1B) and 40 (1B). Continuity
    MIR HTR 50(1B)-48(1B) Always Continuity
    MIR HTR 2(1C)-66(1B) Apply B+ between terminals 50 (1B) and 48 (1B). Continuity
    RRHTR 50 (1B) - 52 (1B) Always Continuity
    RRHTR 50 (1B) - 57 (1B) Always Continuity
    RRHTR 2 (1C) -71 (1B) Apply B+ between terminals 50 (1B) and 52 (1B). Continuity
    RRHTR 70 (1B) - 71 (1B) Apply B+ between terminals 50 (1B) and 52 (1B). Continuity
    FRFOG 61 (1A) -59(1B) Always Continuity
    FRFOG 2 (1C)-62(1 A) Apply B+ between terminals 61 (1 A) and 59 (1B). Continuity
    FRFOG 2 (1C)-64(1 A) Apply B+ between terminals 61 (1 A) and 59 (1B). Continuity
    TAIL 2(1C)-49(1B) Always Continuity
    TAIL 2 (1C)-51(1 A) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    TAIL 2 (1C)-50(1 A) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    TAIL 2 (1C)-59(1 A) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    TAIL 2 (1C)-49(1 A) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    TAIL 2 (1C)-58(1 A) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    TAIL 2(1C)-60(1B) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    TAIL 2(1C)-58(1B) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    TAIL 2(1C)-67(1B) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    TAIL 2(1C)-69(1B) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    PANEL 2(1C)-64(1B) Apply B+ between terminals 2 (1C) and 49 (1B). Continuity
    HEAD 1 (1C) -22(1B) Always Continuity
    HEAD 1(1C)-33(1B) Apply B+ between terminals 1 (1C) and 22 (1B). Continuity
    HEAD 1 (1C) - 19 (1A) Apply B+ between terminals 1 (1C) and 22 (1B). Continuity
    HEAD 1 (1C) -26(1 A) Apply B+ between terminals 1 (1C) and 22 (1B). Continuity
    HEAD 1 (1C) -28(1 A) Apply B+ between terminals 1 (1C) and 22 (1B). Continuity
    HEAD 1(1C)-20(1A) Apply B+ between terminals 1 (1C) and 22 (1B). Continuity
    HEAD 1 (1C)-9(1A) Apply B+ between terminals 1 (1C) and 22 (1B). Continuity
    HEAD HI 1 (1C) - 10 (1B) Always Continuity
    HEAD HI 1(1C)-12(1A) Apply B+ between terminals 1 (1C) and 10 (1B). Continuity
    HEAD HI 1 (1C) - 1 (1B) Apply B+ between terminals 1 (1C) and 10 (1B). Continuity
    HEAD HI 1 (1C) -8(1 A) Apply B+ between terminals 1 (1C) and 10 (1B). Continuity
    HORN 1(1C)-21(1B) Always Continuity
    HORN 1 (1C) -4(1 A) Apply B+ between terminals 1 (1C) and 21 (1B). Continuity
    HORN 1(1C)-15(1A) Apply B+ between terminals 1 (1C) and 21 (1B). Continuity

    If the circuit is not as specified, replace it with relay block assembly.

    HINT:

    The relay is built in the engine room junction block. Also the relay is constructed with a relay block that is in the junction block as a unit. To disconnect the wire harness connecting with relay block is impossible. If the relay has a malfunction, replace it with the relay block assembly wire harness together.

  2. INSPECT COWL SIDE JUNCTION BLOCK LH CIRCUIT 
    Fig 5: Identifying Cowl Side Junction Block LH
    G02994059Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 6: Identifying Cowl Side Junction Block LH (Back Side)
    G02994060Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the fuse from the junction block and inspect the connector on the junction block side.
      FUSE TESTER CONNECTION AND SPECIFIED CONDITION

      Fuse Tester connection Condition Specified condition
      AHC-IG 2 - Ground Ignition switch ON Battery positive voltage
      POWER HTR 4 - Ground Ignition switch ON Battery positive voltage
      FUEL HTR 6 - Ground Ignition switch ON Battery positive voltage
      AHC-B 8 - Ground Always Battery positive voltage
      DEFOG 10 - Ground Always Battery positive voltage
      AM1 12 - Ground Always Battery positive voltage
      ACC 13 - Ground Ignition switch ACC Battery positive voltage
      CIG 15 - Ground Ignition switch ACC Battery positive voltage
      PWR OUTLET 17 - Ground Ignition switch ACC Battery positive voltage
      OBD-220 - Ground Always Battery positive voltage
      STOP 22 - Ground Always Battery positive voltage
      A/C 24 - Ground Ignition switch ON Battery positive voltage
      BATT CHARGE 26 - Ground Always Battery positive voltage
      DBL LOCK 39 - Ground Always Battery positive voltage
      ECU-B1 29 - Ground Always Battery positive voltage
      ECU-IG1 32 - Ground Ignition switch ON Battery positive voltage
      GAUGE1 34 - Ground Ignition switch ON Battery positive voltage
      EFI or ECD NO.2 35 - Ground Always Battery positive voltage
      RR WIPER 37-Ground Ignition switch ON Battery positive voltage
      SUN ROOF 39 - Ground Always Battery positive voltage
      DOOR 41 - Ground Always Battery positive voltage
      LH SEAT 43 - Ground Always Battery positive voltage
      IDLE UP 46 - Ground Rear defogger system ON Battery positive voltage

      If the circuit is not as specified, inspect the circuits connected to other parts.

    2. Remove the relay from the junction block and inspect the connector on the junction block side.
      RELAY TESTER CONNECTION AND SPECIFIED CONDITION

      Relay Tester connection Condition Specified condition
      DOME 1 - Ground Always Battery positive voltage
      DOME 5 - Ground Always Battery positive voltage
      ACC 5 - Ground Always Battery positive voltage
      ACC 2 - Ground Ignition switch ON Battery positive voltage
      IG1 NO.2 5 - Ground Always Battery positive voltage
      IG1 NO.2 2 - Ground Ignition switch ON Battery positive voltage
      DEFOG 5 - Ground Always Battery positive voltage
      DEFOG 1 - Ground Ignition switch ON Battery positive voltage

      If the circuit is not as specified, inspect the circuits connected to other parts.

  3. INSPECT COWL SIDE JUNCTION BLOCK RH CIRCUIT 
    Fig 7: Identifying Cowl Side Junction Block RH
    G02994061Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 8: Identifying Cowl Side Junction Block RH (Back Side)
    G02994062Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the fuse from the junction block and inspect the connector on the junction block side.
    FUSE TESTER CONNECTION AND SPECIFIED CONDITION

    Fuse Tester connection Condition Specified condition
    P/W (RL) 2 - Ground Always Battery positive voltage
    P/W (FL) 4 - Ground Always Battery positive voltage
    VGRS 2 - Ground Always Battery positive voltage
    DOME 5 - Ground Always Battery positive voltage
    RADIO 7 - Ground Always Battery positive voltage
    WASHER 10 - Ground Ignition switch ON Battery positive voltage
    DIFF 12 - Ground Ignition switch ON Battery positive voltage
    ECU-B2 13 - Ground Always Battery positive voltage
    P/W(FR) 15 - Ground Always Battery positive voltage
    P/W(RR) 17 - Ground Always Battery positive voltage
    SECURITY 20 - Ground Always Battery positive voltage
    IGN 21 - Ground Ignition switch ON Battery positive voltage
    MET 23 - Ground Ignition switch ON Battery positive voltage
    GAUGE2 25 - Ground Ignition switch ON Battery positive voltage
    SEAT HTR 27 - Ground Ignition switch ON Battery positive voltage
    ECU-IG2 29 - Ground Ignition switch ON Battery positive voltage
    WIPER 31 - Ground Ignition switch ON Battery positive voltage
    RH SEAT 33 - Ground Always Battery positive voltage
    RR A/C 35 - Ground Always Battery positive voltage
    TIL & TEL 37-Ground Always Battery positive voltage

    If the circuit is not as specified, inspect the circuits connected to other parts.

    Remove the relay from the junction block and inspect the connector on the junction block side.

    RELAY TESTER CONNECTION AND SPECIFIED CONDITION

    Relay Tester connection Condition Specified condition
    ACC CUT 2 - Ground Always Battery positive voltage
    ACC CUT 4 - Ground Ignition Switch ACC Battery positive voltage
    IG1 NO.3 5 - Ground Always Battery positive voltage
    IG1 NO.3 2 - Ground Ignition Switch ON Battery positive voltage

    If the circuit is not as specified, inspect the circuits connected to other parts.

scientia non olet · About LEMON Manuals