Lexus IS250 · Service Manual BODY ELECTRICAL

TERMINALS OF ECU

System information


CHECK ENGINE ROOM NO. 2 R/B (FRONT CONTROLLER)
E108357E03
Symbols (Terminal No.)
Wiring Color
Terminal Description
Condition
Specified Condition
ALTB (2E-1) - Body ground
W - Body ground
Power source circuit
Always
10 to 14 V
BATB (2E-2) - Body ground
W-L - Body ground
Power source circuit
Always
10 to 14 V
FMIG (2E-3) - Body ground
B-Y - Body ground
Engine switch signal circuit
Engine switch on (IG)
10 to 14 V
FMIG (2E-3) - Body ground
B-Y - Body ground
Engine switch signal circuit
Engine switch off
Below 1 V
FMB3 (2E-4) - Body ground
G-R - Body ground
Power source circuit
Always
10 to 14 V
E (2F-1) - Body ground
W-B - Body ground
Ground
Always
Below 1 V
MPX1 (2F-5) - Body ground
L - Body ground
Multiplex communication signal circuit
Engine switch on (IG)
Signal waveform
MPX2 (2F-6) - Body ground
GR - Body ground
Multiplex communication signal circuit
Engine switch on (IG)
Signal waveform
FOGR (2G-6) - Body ground
LG - Body ground
Fog light circuit
(To front fog light RH)
Front fog light ON
10 to 14 V
FOGR (2G-6) - Body ground
LG - Body ground
Fog light circuit
(To front fog light RH)
Front fog light OFF
Below 1 V
FOGL (2G-7) - Body ground
G-R - Body ground
Fog light circuit
(To front fog light LH)
Front fog light ON
10 to 14 V
FOGL (2G-7) - Body ground
G-R - Body ground
Fog light circuit
(To front fog light LH)
Front fog light OFF
Below 1 V
CRAR (2G-8) - Body ground
G -Body ground
Taillight circuit
(To parking light RH)
Light control switch on TAIL
10 to 14 V
CRAR (2G-8) - Body ground
G -Body ground
Taillight circuit
(To parking light RH)
Light control switch OFF
Below 1 V
CRAL (2G-9) - Body ground
G -Body ground
Taillight circuit
(To parking light LH)
Light control switch on TAIL
10 to 14 V
CRAL (2G-9) - Body ground
G -Body ground
Taillight circuit
(To parking light LH)
Light control switch OFF
Below 1 V
HLHR (2G-12) - Body ground
R-W -Body ground
Hi-beam circuit
(To headlight RH)
Headlight dimmer switch on HI
10 to 14 V
HLHR (2G-12) - Body ground
R-W -Body ground
Hi-beam circuit
(To headlight RH)
Headlight dimmer switch on HEAD
Below 1 V
HLHL (2G-13) - Body ground
R-Y -Body ground
Hi-beam circuit
(To headlight LH)
Headlight dimmer switch on HI
10 to 14 V
HLHL (2G-13) - Body ground
R-Y -Body ground
Hi-beam circuit
(To headlight LH)
Headlight dimmer switch on HEAD
Below 1 V
(2G-4) - Body ground
R-L - Body ground
Hi-beam circuit
Headlight dimmer switch on HI
10 to 14 V
(2G-4) - Body ground
R-L - Body ground
Hi-beam circuit
Headlight dimmer switch on HEAD
Below 1 V
(2G-10) - Body ground
G-Y - Body ground
Taillight circuit
(To marker light RH)
Light control switch on TAIL
10 to 14 V
(2G-10) - Body ground
G-Y - Body ground
Taillight circuit
(To marker light RH)
Light control switch OFF
Below 1 V
(2G-11) - Body ground
BR - Body ground
Taillight circuit
(To marker light LH)
Light control switch on TAIL
10 to 14 V
(2G-11) - Body ground
BR - Body ground
Taillight circuit
(To marker light LH)
Light control switch OFF
Below 1 V

CHECK MAIN BODY ECU RH (COWL SIDE J/B RH)
E106665E19
Symbols (Terminal No.)
Wiring Color
Terminal Description
Condition
Specified Condition
GND2 (RD-7) - Body ground
W-B - Body ground
Ground
Always
Below 1 V
LCTY (RA-11) - Body ground
BR - Body ground
Illumination signal
(From door courtesy switch rear LH)
Rear LH door is closed
10 to 14 V
LCTY (RA-11) - Body ground
BR - Body ground
Illumination signal
(From door courtesy switch rear LH)
Rear LH door is open
Below 1 V
MPX1 (RJ-21) - Body ground
GR - Body ground
Multiplex communication signal circuit
Engine switch on (IG)
Signal waveform
BECU (RK-5) - Body ground
G-R - Body ground
Multiplex communication power source circuit
Always
10 to 14 V
HRLY (RL-7) - Body ground
R-W - Body ground
HEAD signal
(To HEAD relay)
Light control switch OFF or in TAIL
10 to 14 V
HRLY (RL-7) - Body ground
R-W - Body ground
HEAD signal
(To HEAD relay)
Light control switch in HEAD
Below 1 V
DCTY (P1-14) - Body ground
W - Body ground
Illumination signal
(From driver side courtesy switch)
Driver's side door is closed
10 to 14 V
DCTY (P1-14) - Body ground
W - Body ground
Illumination signal
(From driver side courtesy switch)
Driver's side door is open
Below 1 V
RCTY (P1-16) - Body ground
O - Body ground
Illumination signal
(From door courtesy switch rear RH)
Rear door RH is closed
10 to 14 V
RCTY (P1-16) - Body ground
O - Body ground
Illumination signal
(From door courtesy switch rear RH)
Rear door RH is open
Below 1 V
FSPT (J75-15) - Body ground
R - Body ground
Illumination signal
(To footwell lights)
Footwell lights come on
Below 1 V
FSPT (J75-15) - Body ground
R - Body ground
Illumination signal
(To footwell lights)
Footwell lights go off
10 to 14 V
MPX2 (J75-21) - Body ground
GR - Body ground
Multiplex communication signal circuit
Engine switch on (IG)
Signal waveform
CLTE (J74-4) - Body ground
W - Body ground
Automatic light control sensor ground circuit
Always
Below 1 V
CLTS (J74-5) - Body ground
R - Body ground
Automatic light control sensor ground circuit
Engine switch off
Below 1 V
CLTS (J74-5) - Body ground
R - Body ground
Automatic light control sensor ground circuit
Engine switch on (IG), light control switch on AUTO, headlight comes ON
Signal waveform
CLTB (J74-6) - Body ground
GR - Body ground
Automatic light control sensor power source circuit
Engine switch off
Below 1 V
CLTB (J74-6) - Body ground
GR - Body ground
Automatic light control sensor power source circuit
Engine switch on (IG)
10 to 14 V
HEAD (J74-23) - Body ground
L - Body ground
HEAD signal
(From light control switch)
Light control switch OFF or on TAIL
10 to 14 V
HEAD (J74-23) - Body ground
L - Body ground
HEAD signal
(From light control switch)
Light control switch in HEAD
Below 1 V
ALTB (RA-15) - Body ground
SB - Body ground
Power source circuit
Always
10 to 14 V
UL2 (J75-4) - Body ground
O - Body ground
Interior light switch )ON / OFF) signal
Interior light switch ON
Below 1 V
UL2 (J75-4) - Body ground
O - Body ground
Interior light switch )ON / OFF) signal
Interior light switch OFF
10 to 14 V
TRLY (RD-1) - Body ground
Y - Body ground
HEAD signal (to HEAD relay)
Light control switch OFF
10 to 14 V
TRLY (RD-1) - Body ground
Y - Body ground
HEAD signal (to HEAD relay)
Light control switch in TAIL
Below 1 V
PCYL (J75-24) - Body ground
G - Body ground
Illumination signal
(From door courtesy light front LH)
Passenger's side door is open
Below 1 V
PCYL (J75-24) - Body ground
G - Body ground
Illumination signal
(From door courtesy light front LH)
Passenger's side door is closed
10 to 14 V
DCYL (P1-13) - Body ground
G - Body ground
Illumination signal
(From door courtesy light front RH)
Driver's side door is open
Below 1 V
DCYL (P1-13) - Body ground
G - Body ground
Illumination signal
(From door courtesy light front RH)
Driver's side door is closed
10 to 14 V
LGCY (J75-25) - Body ground
L - Body ground
Illumination signal
(From door courtesy switch luggage)
Luggage door is open
Below 1 V
LGCY (J75-25) - Body ground
L - Body ground
Illumination signal
(From door courtesy switch luggage)
Luggage door is closed
10 to 14 V
PCTY (J75-23) - Body ground
B - Body ground
Illumination signal
(From door courtesy switch front LH)
Passenger's side door is open
Below 1 V
PCTY (J75-23) - Body ground
B - Body ground
Illumination signal
(From door courtesy switch front LH)
Passenger's side door is closed
10 to 14 V
HAZ (J74-2) - Body ground
Y - Body ground
HAZARD signal (From HAZARD switch)
HAZARD switch ON
Below 1 V
HAZ (J74-2) - Body ground
Y - Body ground
HAZARD signal (From HAZARD switch)
HAZARD switch OFF
10 to 14 V

CHECK MAIN BODY ECU LH
E107417E14
Symbols (Terminal No.)
Wiring Color
Terminal Description
Condition
Specified Condition
GND (LD-3) - Body ground
W-B - Body ground
Ground
Always
Below 1 V
TR (LA-15) - Body ground
P - Body ground
RH side turn signal
(To turn signal flasher assembly)
Engine switch off
Below 1 V
TR (LA-15) - Body ground
P - Body ground
RH side turn signal
(To turn signal flasher assembly)
Engine switch on (IG) and turn signal switch (right turn) ON
10 to 14 V
(60 to 120 times per minute)
TL (LA-16) - Body ground
BR - Body ground
LH side turn signal
(To turn signal flasher assembly)
Engine switch off
Below 1 V
TL (LA-16) - Body ground
BR - Body ground
LH side turn signal
(To turn signal flasher assembly)
Engine switch on (IG) and turn signal switch (left turn) ON
10 to 14 V
(60 to 120 times per minute)
SGND (LD-8) - Body ground
W-B - Body ground
Ground
Always
Below 1 V
SGND (LD-9) - Body ground
W-B - Body ground
Ground
Always
Below 1 V
MPXB (LD-18) - Body ground
LG - Body ground
Multiplex communication power source circuit
Always
10 to 14 V
ILE (A36-2) - Body ground
V - Body ground
Illumination signal
(To front interior light)
Interior light switch in DOOR position and interior lights come on
Below 1 V
ILE (A36-2) - Body ground
V - Body ground
Illumination signal
(To front interior light)
Interior light switch in DOOR position and interior lights come on
10 to 14 V
RCTY (Q1-3) - Body ground
R - Body ground
Illumination signal
(To shift illumination light rear RH)
Shift illumination comes on
Below 1 V
RCTY (Q1-3) - Body ground
R - Body ground
Illumination signal
(To shift illumination light rear RH)
Shift illumination goes off
10 to 14 V
LCTY (Q1-4) - Body ground
LG - Body ground
Illumination signal
(To door mirror foot lights)
Door mirror foot light comes on
10 to 14 V
MPX1 (Q3-15) - Body ground
GR - Body ground
Multiplex communication signal circuit
Engine switch on (IG)
Signal waveform
RFRL (LJ-25) - Body ground
O - Body ground
RR Foglight signal (to RR Foglight)
RR Foglight switch in OFF
10 to 14 V
RFRL (LJ-25) - Body ground
O - Body ground
RR Foglight signal (to RR Foglight)
RR Foglight switch in ON
Below 1 V
MPX2 (A30-17) - Body ground
GR - Body ground
Multiplex communication signal circuit
Engin switch on (IG)
Signal waveform
ILE1 (LA-19) - Body ground
W - Body ground
Illumination signal (to scuff plate light)
Room light switch in DOOR position and scuff plate lights comes on
Below 1 V
ILE1 (LA-19) - Body ground
W - Body ground
Illumination signal (to scuff plate light)
Room light switch in DOOR position and scuff plate lights comes off
10 to 14 V
LGCY (Q3-3) - Body ground
W - Body ground
Illumination signal (to seat illumination)
Seat illumination comes on
Below 1 V
LGCY (Q3-3) - Body ground
W - Body ground
Illumination signal (to seat illumination)
Seat illumination comes off
10 to 14 V
BDCY (Q3-11) - Body ground
P - Body ground
Interior light switch (Door) signal
Interior light switch on
Below 1 V
BDCY (Q3-11) - Body ground
P - Body ground
Interior light switch (Door) signal
Interior light switch off
10 to 14 V

CHECK COMBINATION SWITCH ASSEMBLY (Windshield Wiper Switch)
E106675E12
Symbols (Terminal No.)
Wiring Color
Terminal Description
Condition
Specified Condition
B (J26-1) - E (J26-5)
LG - W-B
Power source circuit
(From battery)
Always
10 to 14 V
IG (J26-2) - E (J26-5)
B - W-B
Engine switch signal circuit
(From engine switch)
Engine switch off
Below 1 V
IG (J26-2) - E (J26-5)
B - W-B
Engine switch signal circuit
(From engine switch)
Engine switch on (IG)
10 to 14 V
HEAD (J26-4) - Body ground
L - Body ground
Light control switch HEAD signal
Light control switch not on HEAD
10 to 14 V
HEAD (J26-4) - Body ground
L - Body ground
Light control switch HEAD signal
Light control switch on HEAD
Below 1 V
E (J26-5) - Body ground
W-B - Body ground
Ground
Always
Below 1 V
MPX1 (J26-6) - Body ground
GR - Body ground
Multiplex communication signal circuit
Engine switch on (IG)
Signal waveform
MPX2 (J26-7) - Body ground
GR - Body ground
Multiplex communication signal circuit
Engine switch on (IG)
Signal waveform

CHECK OVERHEAD J/B
E100449E01
Symbols (Terminal No.)
Wiring Color
Terminal Description
Condition
Specified Condition
+B1 (R5-1) - Body ground
L - Body ground
Power source circuit
Always
10 to 14 V
RRMP (R5-3) - Body ground
O - Body ground
Rear personal light power source circuit
Always
10 to 14 V
ILLB (R5-4) - Body ground
L - Body ground
Rear interior light power source circuit
Always
10 to 14 V
CTY (R5-12) - Body ground
W - Body ground
Seat illumination light circuit
Seat illumination light comes off
10 to 14 V
CTY (R5-12) - Body ground
W - Body ground
Seat illumination light circuit
Seat illumination light comes on
Below 1 V
ILL (R5-13) - Body ground
BR - Body ground
Interior light circuit
Interior light comes off
10 to 14 V
ILL (R5-13) - Body ground
BR - Body ground
Interior light circuit
Interior light comes on
Below 1 V
SHFT (R5-14) - Body ground
Y - Body ground
Shift illumination circuit
Shift illumination comes off
10 to 14 V
SHFT (R5-14) - Body ground
Y - Body ground
Shift illumination circuit
Shift illumination comes on
Below 1 V
GND3 (R5-18) - Body ground
W-B - Body ground
Ground
Always
Below 1 V
RGND (R5-19) - GND3 (R5-18)
W-B - W-B
Interior light ground
Always
Below 1 V
LILL (R5-32) - CTY (R5-12)
B - W
Seat illumination circuit
Always
Below 1 Ω
RILL (R5-33) - ILL (R5-13)
P - BR
Interior light circuit
Always
Below 1 Ω
CILL (R5-34) - GND3 (R5-18)
P - W-B
Interior light switch (ON/OFF) circuit
Interior light switch off
10 to 14 V
CILL (R5-34) - GND3 (R5-18)
P - W-B
Interior light switch (ON/OFF) circuit
Interior light switch on
Below 1 V
DOOR (R5-35) - GND3 (R5-18)
G - W-B
Interior light switch (DOOR) circuit
Interior light switch off
10 to 14 V
DOOR (R5-35) - GND3 (R5-18)
G - W-B
Interior light switch (DOOR) circuit
Interior light switch on
Below 1 V

CHECK AFS ECU
*1: RHD
*2: LHD
*3: With AFS
E107316E05
Symbols (Terminal No.)
Wiring Color
Terminal Description
Condition
Specified Condition
SBF (A28-1) - SGF (A28-17)
R-B - G-R
Vehicle height signal (To height control sensor)
Engine switch off
Below 1 V
Engine switch on (IG)
4.5 V to 5.5 V
SPDL (A28-6) - E1 (A27-1)
P-B - W-B *1
R-L - W-B *2
Vehicle speed signal
(To skid control ECU)
Vehicle is driving at approx. 30 km/h (19 mph)
Pulse generation
(see waveform 1)
SPDR (A28-7) - E1 (A27-1)
G-W - W-B
Vehicle speed signal
(To skid control ECU)
Vehicle is driving at approx. 30 km/h (19 mph)
Pulse generation
(see waveform 1)
BR1+ (A28-9) - BR1- (A28-10)
LG-R - O
Headlight swivel motor RH
Engine switch off
Below 1 V
Engine running, light control switch in HEAD, driving at more than 10 km/h (6 mph) and turning the steering wheel to right more than 7.5°
Pulse generation
(see waveform 2)
BR2+ (A28-11) - BR2- (A28-12)
L-B - L-Y
Headlight swivel motor RH
Engine Switch off
Below 1 V
Engine running, light control switch in HEAD, driving at more than 10 km/h (6 mph) and turning the steering wheel more than 7.5°
Pulse generation
(see waveform 2)
LR1+ (A28-13) - LR1- (A28-14)
L - BR-W
Headlight leveling actuator RH
Engine Switch off
Below 1 V
Engine running, light control switch in HEAD, the vehicle is standing still or bounding
Pulse generation
(see waveform 3)
LR2+ (A28-15) - LR2- (A28-16)
P - LG
Headlight leveling actuator RH
Engine Switch off
Below 1 V
Engine running, light control switch in HEAD, the vehicle is standing still or bounding
Pulse generation
(see waveform 3)
SGF (A28-17) - E1 (A27-1)
G - R
Vehicle height signal (To height control sensor)
Always
Below 1 V
SMGR (A28-18) - E1 (A27-1)
W-R - W-B
Headlight swivel motor RH
Always
Below 1 V
SMGL (A28-19) - E1 (A27-1)
P-G - W-B
Headlight swivel motor LH
Always
Below 1 V
SMBR (A28-21) - SMGR (A28-18)
GR - W-R
Headlight swivel motor RH
Engine switch off
Below 1 V
Engine switch on (IG)
4.5 V to 5.5 V
SMBL (A28-22) - SMGL (A28-19)
W - P-G
Headlight swivel motor LH
Engine switch off
Below 1 V
Engine switch on (IG)
4.5 V to 5.5 V
SMR (A28-23) - SMGR (A28-18)
G-B - W-R
Headlight swivel motor RH
Engine switch off
Below 1 V
Engine switch on (IG)
0.3 V to 4.6 V
SML (A28-24) - SMGL (A28-19)
Y-B - P-G
Headlight swivel motor LH
Engine switch off
Below 1 V
Engine switch on (IG)
0.3 V to 4.6V
BL1+ (A28-25) - BL1-(A28-26)
B-L - L-W
Headlight swivel motor LH
Engine switch off
Below 1 V
Engine running, light control switch in HEAD, driving at more than 10 km/h (6 mph) and turning the steering wheel to left more than 7.5°
Pulse generation
(see waveform 2)
BL2+ (A28-27) - BL2-(A28-28)
L-R - B-Y
Headlight swivel motor LH
Engine Switch off
Below 1 V
Engine running, light control switch in HEAD, driving at more than 10 km/h (6 mph) and turning the steering wheel to left more than 7.5°
Pulse generation
(see waveform 2)
LL1+ (A28-29) - LL1-(A28-30)
R-G - G
Headlight leveling actuator LH
Engine Switch off
Below 1 V
Engine running, light control switch in HEAD, the vehicle is still or bounced
Pulse generation
(see waveform 3)
LL2+ (A28-31) - LL2-(A28-32)
Y-R - V-R
Headlight leveling actuator LH
Engine switch off
Below 1 V
Engine running, light control switch in HEAD, the vehicle is still or bounced
Pulse generation
(see waveform 3)
E1 (A27-1) - Body ground
W-B - Body ground
Ground
Always
Below 1 V
IG (A27-2) - E1 (A27-1)
B-O - W-B
Power source circuit
(To engine switch)
Engine switch off
Below 1 V
Engine switch on (IG)
10 to 14 V
MPX1 (A27-5) - E1 (A27-1)
BR - W-B *3
Multiplex communication signal
Engine switch on (IG)
Signal waveform
MPX2 (A27-6) - E1 (A27-1)
BR-B - W-B *3
Multiplex communication signal
Engine switch on (IG)
Signal waveform
SS+ (A27-7) -SS- (A27-8)
L - LG
Steering sensor signal
(To position sensor)
Engine idling, slowly turn steering wheel
Pulse generation
SHRL (A27-9) - SGR (A27-20)
B-W - R-Y
Vehicle height signal
(To height control sensor rear)
Engine switch off
Below 1 V
Engine switch on (IG) , bouncing the vehicle
0.5 to 4.5 V
SHFL (A28-2) - SGF (A28-17)
G-Y - G-R
Vehicle height signal
(To height control sensor front)
Engine Switch off
Below 1 V
Engine Switch on (IG) , bouncing the vehicle
0.5 to 4.5 V
SBR (A27-10) - SGR (A27-20)
W - R-Y
Vehicle height signal
(To height control sensor rear)
Engine switch off
Below 1 V
Engine switch on (IG)
4.5 to 5.5 V
SBF (A28-1) - SGF (A28-17)
R-B - G-R
Vehicle height signal
(To height control sensor front)
Engine switch off
Below 1 V
Engine switch on (IG)
4.5 to 5.5 V

  1. E038308E01
    Waveform 1
    Item
    Contents
    Terminal
    SPDL - GND
    SPDR - GND
    Tool setting
    5 V/DIV., 2 ms./DIV.
    Vehicle condition
    Vehicle is driving at approximately 30 km/h (19 mph)

  2. E109833
    Waveform 2
    Item
    Contents
    Terminal
    BL1+ - BL1-
    BL2+ - BL2-
    BR1+ - BR1-
    BR2+ - BR2-
    Tool setting
    10 V/DIV., 5 ms./DIV.
    Vehicle condition
    1. Engine running, light control switch in HEAD, driving at more than 10 km/h (6 mph) and turning the steering wheel more than 7.5°
    2. If the value is not within the standard range, it is possible there is some defect on the vehicle side. Inspect the fuse, wire harness and connector.

  3. E109834
    Waveform 3
    Item
    Contents
    Terminal
    LR1+ - LR1-
    LR2+ - LR2-
    LL1+ - LL1-
    LL2+ - LL2-
    Tool setting
    10 V/DIV., 5 ms./DIV.
    Vehicle condition
    1. Engine running, light control switch in HEAD, driving at more than 10 km/h (6 mph) and turning the steering wheel more than 7.5°
    2. If the value is not within the standard range, it is possible there is some defect on the vehicle side. Inspect the fuse, wire harness and connector.

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