
HEADLIGHT
J1
JUNCTION
CONNECTOR
2 B B R- B
4 1
HEAD RELAY
40A MAIN
B
R- B
R- B
R- B
R
R
1 3 2
7 7 7 4 2G 7
3 2B 8 2K 3 2G
1 3 1 1
10A H- LP RH LO
10A H- LP LH LO
DIM RELAY
15A HEAD RH
15A HEAD LH
W
O
4
R- W
2 5
2 2
7 7 5 2G 2 2G 7 7
R
R- W
R- Y
R- L
R- Y
2 1 2 1
H1 H2
2 EB1 HEADLIGHT HEADLIGHT
LH RH
3 3
R- Y
R- B
CONNECTOR
A
JUNCTION
A R- B
J1
A
R- B
R- B
4
G- R G- R
EB1
J7
7 7 JUNCTION
CONNECTOR
F8
FUSIBLE LINK E E R- L
BLOCK 1 5
W
DRL RELAY
R- G
E
1
R- L
2 3 12 A (* 1)
7 B (* 2)
B- L
H
INTEGRATION
R- L
I13 A , B
7 7
R- Y
RELAY
HRLY
R- W
FL MAIN 11 A (* 1) O
3. 0W 6 B (* 2)
G- R
O
3 EB1
R- W
W- B
W- B
5 3A 14 3A
R- L
(DAYTIME RUNNING
1 R- G
LIGHT NO. 2)
BATTERY 15 3A
DIODE
2
R- L R- L
D8
W- B
EE
2001 SIENNA (EWD420U)
76
FROM POWER SOURCE SYSTEM (SEE PAGE 52)
G1
* 1 : W/ DOOR LOCK CONTROL
GENERATOR
TO ACTIVE LIGHT RELAY * 2 : W/O DOOR LOCK CONTROL
* 3 : W/ VSC
10A 10A * 4 : W/O VSC
DOME GAUGE
(*3)
R
L
B- O
(*4)
1
W- B
12 2J 2 1D
C 9 B , C10 A , C11 C
R- W
COMBINATION METER
Y
5 B 6 C
GR
BRAKE
BEAM
HIGH
3 1W
Y- R
1 IK3 (* 3)
9 A 3 C
A 1
10 1V A GR
P3
(*4) PARKING
BRAKE SW
(* 3)
GR
R
Y
J17
JUNCTION
CONNECTOR
CONNECTOR
JUNCTION
A E D
J18 A GR D
JUNCTION
J5
CONNECTOR (*3)
FROM TRANSLATE ECU
A E A J18
Y- R
R- G
JUNCTION
(* 4)
GR
B
CONNECTOR
R
Y
(* 3)
3 9 12 5 11
+B CHG- IG IND PKB
DIM H- LP DRL H E HI FOG BRK
Y- R
(*3)
4 6 1 7 2 D4 8 16 10
DAYTIME RUNNING
LIGHT RELAY (MAIN)
R- W
B- O
R- B
B- Y
(* 4)
(* 4)
W- B
G- R
R- Y
R- L
O
C12
COMBINATION SW 7 19 3B 8 3B
FROM FOG LIGHT SW
HF H T EL HU
CONTROL SW
OFF
[COMB. SW]
9 3B
TAIL
W- B
LIGHT
Y- R
HEAD
(* 3)
B- O
(* 4)
LOW
DIMMER SW
R- W FROM
6 EB1 (*3) TRANSLATE ECU
R- Y HIGH 1
O FLASH B1
BRAKE FLUID
8 13 16 LEVEL
G- R J2 A , J3 B WARNING SW
W- B
JUNCTION
W- B
R- G
R- L
CONNECTOR 2
B
W- B
R- L B
B B W- B
R- G B A
A A
B A
W- B
W- B
R- L
W- B
W- B
ED IJ
2001 SIENNA (EWD420U)
77
HEADLIGHT
SYSTEM OUTLINE
Voltage from the battery is always applied through the MAIN fuse to the HEAD relay (Coil side), furthermore, to TERMINAL 6
of the daytime running light relay (Main).
1. DAYTIME RUNNING LIGHT OPERATION
When the engine is started, voltage generated at TERMINAL 1 of the generator is applied to TERMINAL 9 of the daytime
running light relay (Main). If the parking brake pedal is depressed (Parking brake SW on) at this time, the relay is not
activated so the daytime running light system does not operate. If the parking brake is released (Parking brake SW off), a
signal is input to TERMINAL 11 of the relay.
This activates the relay, so current flows from the MAIN fuse to the HEAD relay (Point side) to TERMINAL 5 of the DIM relay
to TERMINAL 3 to H-LP LH LO, H-LP RH LO fuse to TERMINAL 1 of the headlights to TERMINAL 3 to TERMINAL 1 of the
daytime running light relay (Main) to GROUND, causing the headlights to light up (Headlights light up dimmer than normal
brightness.). Once the daytime running light system operates and the headlights light up, the headlights remain on even if
the parking brake pedal is depressed (Parking brake SW on).
If the engine stalls and the ignition SW remains on, the headlights remain on even through current is no longer output from
TERMINAL 1 of the generator. If the ignition SW is then turned off, the headlights go off.
If the engine is started with the parking brake released (Parking brake SW off), the daytime running light system operates
and headlights light up when the engine starts.
2. HEADLIGHT OPERATION
When the light control SW is switched to HEAD position , current flows from the MAIN fuse to the HEAD relay (Point side) to
TERMINAL 2 of the DRL relay to TERMINAL 1 to TERMINAL 1 of the diode (Daytime running light no. 2) to TERMINAL 2 to
the integration relay to TERMINAL 13 of the light control SW to TERMINAL 16 to GROUND, activating the DRL relay.
Current then flows from the H-LP LH LO, H-LP RH LO fuse to TERMINAL 1 of the headlights to TERMINAL 3 to TERMINAL
5 of the DRL relay to TERMINAL 3 to GROUND, causing the headlights to light up at normal intensity.
When the dimmer SW is switched to the HIGH position, the signal from the dimmer SW is input to the daytime running light
relay (Main). This activates the relay and current flows from TERMINAL 2 of the DIM relay to TERMINAL 1 to TERMINAL 4
of the daytime running light relay (Main), activating the DIM relay. This causes current to flow from TERMINAL 5 of the DIM
RLY relay to TERMINAL 4 to HEAD LH, HEAD RH fuse to TERMINAL 2 of the headlights to TERMINAL 3 to TERMINAL 5 of
the DRL relay to TERMINAL 3 to GROUND, causing the headlights to light up at high beam and the high beam indicator to
light up.
When the dimmer SW is switched to FLASH position, the daytime running light relay (Main) is activated, the current flowing
from the HEAD relay (Point side) flows the DRL relay to TERMINAL 1 to TERMINAL 1 of the diode (Daytime running light no.
2) to TERMINAL 2 to TERMINAL 8 of the dimmer SW to TERMINAL 16 to GROUND, and the current flowing from the HEAD
relay (Point side) also flows through the HEAD LH, HEAD RH fuse to TERMINAL 2 of the headlights to TERMINAL 3 to
TERMINAL 5 of the DRL relay to TERMINAL 3 to GROUND, causing the headlights to light up at high beam and the high
beam indicator to light up.
SERVICE HINTS
HEAD RELAY
1-2 : Closed with the light control SW at HEAD position or the dimmer SW at FLASH position
Closed with the engine running and the parking brake released (Parking brake SW off)
D4 DAYTIME RUNNING LIGHT RELAY (MAIN)
12-GROUND : Approx. 12 volts with the ignition SW at ON position
4, 7-GROUND : Approx. 12 volts with the light control SW at HEAD position or the dimmer SW at FLASH position
Approx. 12 volts with the engine running and the parking brake is released
(Parking brake SW off)
3, 6-GROUND : Always approx. 12 volts
11-GROUND : Continuity with the parking brake pedal depressed
9-GROUND : 13.9- 15.1 volts with the engine running at 2000 rpm 25