2000 LEXUS GS400 Service Repair Manual

I05032
± BODY ELECTRICALPOWER SOURCE
BE±23
2324 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. INSPECT ENGINE ROOM No.3 RELAY BLOCK CIR-
CUIT
Remove the relay from the relay block and inspect the connec-
tor on relay block side.
Fuse Tester connectionConditionSpecified condition
FAN NO.1 3 ± GroundIgnition switch ONBattery positive voltage
FAN NO.2 8 ± GroundIgnition switch ONBattery positive voltage
A/C COMP 13 ± GroundIgnition switch ONBattery positive voltage
FAN NO.3 17 ± GroundIgnition switch ONBattery positive voltage
DIMMER 20 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.

I05033
BE±24
± BODY ELECTRICALPOWER SOURCE
2325 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
3. INSPECT ENGINE ROOM No.2 RELAY BLOCK CIR-
CUIT
Remove the relay from the relay block and inspect the connec-
tor on relay block side.
Relay Tester connectionConditionSpecified condition
HORN 1 ± GroundConstantBattery positive voltage
HORN 2 ± GroundHorn switch ONContinuity
HORN 4 ± GroundConstantBattery positive voltage
ABS SOL 5 ± GroundConstantBattery positive voltage
ABS SOL 6 ± GroundConstantContinuity
TRC MTR 11 ± GroundConstantBattery positive voltage
ABS MTR 15 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.

I05034
± BODY ELECTRICALPOWER SOURCE
BE±25
2326 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
4. INSPECT DRIVER SIDE JUNCTION BLOCK CIRCUIT

BE±26
± BODY ELECTRICALPOWER SOURCE
2327 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(a) Remove the fuse from the junction block and inspect the
connector on junction block side.
Fuse Tester connectionConditionSpecified condition
AM1 1 ± GroundConstantBattery positive voltage
WASHER 3 ± GroundIgnition switch ONBattery positive voltage
FOG 5 ± GroundConstantBattery positive voltage
TAIL 7 ± GroundLight control switch TAIL or HEADBattery positive voltage
SRS±ACC 9 ± GroundIgnition switch ACC or ONBattery positive voltage
GAUGE 11 ± GroundIgnition switch ONBattery positive voltage
FUEL OPN 13 ± GroundConstantBattery positive voltage
D FR DOOR 15 ± GroundConstantBattery positive voltage
PANEL 17 ± GroundLight control switch TAIL or HEADBattery positive voltage
HTR 19 ± GroundIgnition switch ONBattery positive voltage
SRS±B 21 ± GroundConstantBattery positive voltage
P/SEAT (D) 23 ± GroundConstantBattery positive voltage
RAD NO.2 25 ± GroundIgnition switch ACC or ONBattery positive voltage
WIP 27 ± GroundIgnition switch ONBattery positive voltage
OBD 29 ± GroundConstantBattery positive voltage
STOP 31 ± GroundConstantBattery positive voltage
CIG 33 ± GroundIgnition switch ACC or ONBattery positive voltage
ECU±IG 35 ± GroundIgnition switch ONBattery positive voltage
ST 37 ± GroundIgnition switch ONBattery positive voltage
IGN 39 ± GroundIgnition switch ONBattery positive voltage
D RR DOOR 41 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.
(b) Remove the relay from the junction block and inspect the
connector on junction block side.
Relay Tester connectionConditionSpecified condition
Fog light 43 ± GroundConstantBattery positive voltage
Fog light 44 ± GroundConstantContinuity
Fog light 46 ± GroundLight control switch HEADBattery positive voltage
Taillight 47 ± GroundConstantBattery positive voltage
Taillight 48 ± GroundConstantContinuity
Taillight 50 ± GroundConstantContinuity
If the circuit is not as specified, inspect the circuits connected
to other parts.

I05036
± BODY ELECTRICALPOWER SOURCE
BE±27
2328 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
5. INSPECT PASSENGER SIDE JUNCTION BLOCK CIR-
CUIT

BE±28
± BODY ELECTRICALPOWER SOURCE
2329 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(a) Remove the fuse from the junction block and inspect the
connector on junction block side.
Fuse Tester connectionConditionSpecified condition
DEF 1 ± GroundConstantBattery positive voltage
MIR HTR 7 ± GroundIgnition switch ONBattery positive voltage
S/ROOF 13 ± GroundConstantBattery positive voltage
P FR DOOR 15 ± GroundConstantBattery positive voltage
P/SEAT (P) 23 ± GroundConstantBattery positive voltage
DOME 25 ± GroundConstantBattery positive voltage
S±HTR 27 ± GroundIgnition switch ONBattery positive voltage
TV 31 ± GroundConstantBattery positive voltage
ECU±B2 33 ± GroundConstantBattery positive voltage
P FR DOOR 41 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.
(b) Remove the relay from the junction block and inspect the
connector on junction block side.
Relay Tester connectionConditionSpecified condition
Ignition Main 43 ± GroundIgnition switch ONBattery positive voltage
Mirror Heater 47 ± GroundIgnition switch ONBattery positive voltage
Mirror Heater 50 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.

I05029
1 23 4 5
6 78 9 10
± BODY ELECTRICALPOWER SOURCE
BE±29
2330 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. INSPECT PASSENGER COWL SIDE RELAY BLOCK
CIRCUIT
Remove the relay from the relay block and inspect the connec-
tor on relay block side.
Relay Tester connectionConditionSpecified condition
DEF 1 ± GroundConstantBattery positive voltage
HEATER 6 ± GroundConstantBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.

BE0GD±10
I01372
Ignition SwitchRadio Assembly Tweeter
Front Speakers
Rear Speakers
Tweeter
Radio Assembly LEXUS Navigatioin
System Woofer
Power Amplifier
(NAKAMICHI made)
Driver Side Junction Block

RAD NO.2 FuseEngine Room No.1
Junction Block

ECU±B1 Fuse

RAD NO.1 Fuse
Passenger Side
Junction Block

DOME Fuse CD Auto ChangerCD Magazine
Power Amplifier
(PIONEER made)
BE±216
± BODY ELECTRICALAUDIO SYSTEM
2517 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
LOCATION
The vehicle shown in this illustration is ºGS400º.
All components of ºGS300º other than the ones used for engine are same as ºGS400º.