Lexus IS250 · Service Manual BODY ELECTRICAL

TERMINALS OF ECU

System information


CHECK ENGINE ROOM NO. 2 J/B (FRONT CONTROLLER)
E106799E01
Symbols (Terminal No.)
 Wiring Color
 Terminal Description
 Condition
 Specified Condition
FMIG (2E-3) - E (2F-1)
 B-Y - W-B
 IG signal circuit (to IG relay)
 Engine switch off
 Below 1 V
Engine switch on (IG)
 10 to 14 V
FMB3 (2E-4) - E (2F-1)
 G-R - W-B
 Power source circuit (from battery)
 Always
 10 to 14 V
E (2F-1) - Body ground
 W-B - Body ground
 Ground circuit
 Always
 Below 1 V
W+ (2F-4) - E (2F-1)
 L - W-B
 Windshield washer motor circuit
 Windshield washer motor OFF
 Below 1 V
Windshield washer motor ON
 10 to 14 V
MPX1 (2F-5) - E (2F-1)
 L - W-B
 Multiplex communication signal circuit
 Engine switch on (IG)
 Signal waveform
MPX2 (2F-6) - E (2F-1)
 GR - W-B
 Multiplex communication signal circuit
 Engine switch on (IG)
Signal waveform
FRWA (2F-8) - E (2F-1)
 L-O - W-B
 Headlight cleaner operation signal
 Windshield washer motor OFF
 4.5 to 5.5 V
Windshield washer motor ON
 Below 1 V
WLVL (2F-7) - E (2F-1)
 V - W-B
 Washer fluid level sensor signal
 Washer fluid level is normal
 10 to 14 V
Washer fluid is empty
 Below 1 V

CHECK MAIN BODY ECU RH (COWL SIDE J/B RH)
*1: A/T
*2: M/T
*3: with Power Tilt and Power Telescopic
E106665E18
Symbols (Terminal No.)
 Wiring Color
 Terminal Description
 Condition
 Specified Condition
MPX1 (RA-20) - GND2 (RD-7)
 GR - W-B (*3)
 Multiplex communication signal circuit
 Engine switch on (IG)
 Signal waveform
GND2 (RD-7) - Body ground
 W-B - Body ground
 Ground circuit
 Always
 Below 1 V
MPX1 (RJ-21) - GND2 (RD-7)
 GR - W-B
 Multiplex communication signal circuit
 Engine switch on (IG)
 Signal waveform
BECU (RK-5) - GND2 (RD-7)
 G-R - W-B
 ECU power supply (from battery)
 Always
 10 to 14 V
PKB (RL-9) - GND2 (RD-7) (*1)
PKB (RA-12) - GND2 (RD-7) (*2)
 Y-B - W-B(*1)
Y - W-B(*2)
 Parking brake switch circuit
 Parking brake pedal is depressed
 Below 1 V
Parking brake pedal is released
 10 to 14 V
HDLO (A36-4) - GND2 (RD-7)
 R - W-B
 Headlight signal (to headlight cleaner relay)
 Headlight switch is OFF
 10 to 14 V
Headlight switch is LOW
 Below 1 V
MPX2 (J75-21) - GND2 (RD-7)
 GR - W-B
 Multiplex communication signal circuit
 Engine switch on (IG)
 Signal waveform

CHECK MAIN BODY ECU LH (COWL SIDE J/B LH)
E107417E13
Symbols (Terminal No.)
 Wiring Color
 Terminal Description
 Condition
 Specified Condition
GND (LD-3) - Body ground
 W-B - Body ground
 Ground circuit
 Always
 Below 1 V
SGND (LD-8) - Body ground
 W-B - Body ground
 Signal ground circuit
 Always
 Below 1 V
SGND (LD-9) - Body ground
 W-B - Body ground
 Signal ground circuit
 Always
 Below 1 V
WIG (LK-9) - GND (LD-3)
 L - W-B
 Front wiper motor power source circuit
 Engine switch off
 Below 1 V
Engine switch on (IG)
 10 to 14 V
MPXB (LD-18) - GND (LD-3)
 LG - W-B
 ECU power supply (from battery)
 Always
 10 to 14 V
IG (LM-1) - GND (LD-3)
 W - W-B
 Power source circuit (from battery)
 Always
 10 to 14 V
S/S (A30-1) - GND (LD-3)
 Y - W-B
 Front wiper motor power supply circuit (LOW signal)
 Front wiper switch OFF
 Below 1 V
Front wiper switch LOW
 10 to 14 V
+2 (A30-2) - GND (LD-3)
 R-L - W-B
 Front wiper motor power supply circuit (HI signal)
 Front wiper switch OFF
 Below 1 V
Front wiper switch HI
 10 to 14 V
S/M (A30-3) - GND (LD-3)
 G - W-B
 Front wiper motor operation signal
 Front wiper is operated
 10 to 14 V
Front wiper is stopped
 Below 1 V
MPX2 (A30-17) - GND (LD-3)
 GR - W-B
 Multiplex communication signal circuit
 Engine switch on (IG)
 Signal waveform
2S (Q2-11) - GND (LD-3)
 B - W-B
 Front wiper switch HI signal (to combination switch)
 Front wiper switch OFF
 10 to 14 V
Front wiper switch HI
 Below 1 V
MPX1 (Q3-15) - GND (LD-3)
 GR - W-B
 Multiplex communication signal circuit
 Engine switch on (IG)
 Signal waveform

CHECK WINDSHIELD WIPER SWITCH ASSEMBLY (COMBINATION SWITCH ECU)
E106675E11
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
 IG signal circuit (to IG relay)
 Engine switch off
 Below 1 V
Engine switch on (IG)
 10 to 14 V
2S (J26-3) - E (J26-5)
 G - W-B
 Wiper switch HI signal
 Front wiper switch OFF
 Below 1 V
Front wiper switch HI
 10 to 14 V
E (J26-5) - Body ground
 W-B - Body ground
 Ground circuit
 Always
 Below 1 V
MPX1 (J26-6) - E (J26-5)
 GR - W-B
 Multiplex communication signal circuit
 Engine switch on (IG)
 Signal waveform
MPX2 (J26-7) - E (J26-5)
 GR - W-B
 Multiplex communication signal circuit
 Engine switch on (IG)
 Signal waveform

CHECK HEADLIGHT CLEANER CONTROL RELAY
E119074E02
Symbols (Terminal No.)
 Wiring Color
 Terminal Description
 Condition
 Specified Condition
IG (A3-3) - E (A3-4)
 Y - W-B
 Engine switch on (IG) signal (Power source circuit)
 Engine switch off
 Below 1 V
IG (A3-3) - E (A3-4)
 Y - W-B
 Engine switch on (IG) signal (Power source circuit)
 Engine switch on (IG)
 10 to 14 V
PB (A3-6) - E (A3-4)
 W-G - W-B
 Headlight cleaner motor operation signal
 Headlight cleaner motor is stopped
 Below 1 V
PB (A3-6) - E (A3-4)
 W-G - W-B
 Headlight cleaner motor operation signal
 Headlight cleaner motor is operating
 10 to 14 V
HDLO (A3-1) - E (A3-4)
 R - W-B
 Daytime running light system operation signal
 Daytime running light is not operating
 Below 1 V
HDLO (A3-1) - E (A3-4)
 R - W-B
 Daytime running light system operation signal
 Daytime running light is operating
 10 to 14 V
H (A3-2) - E (A3-4)
 R-G - W-B
 Headlight cleaner switch operation signal
 Headlight cleaner switch is OFF
 Below 1 V
H (A3-2) - E (A3-4)
 R-G - W-B
 Headlight cleaner switch operation signal
 Headlight cleaner switch is ON
 10 to 14 V
E (A3-4) - Body ground
 W-B - Body ground
 Body ground
 Always
 Below 1 V
FRWA (A3-5) - E (A3-4)
 L-O - W-B
 Front washer motor operation signal
 Front washer switch is OFF
 Below 1 V
FRWA (A3-5) - E (A3 -4)
 L-O - W-B
 Front washer motor operation signal
 Front washer switch is ON
 10 to 14 V
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