Automatic Light Control Operation - Toyota Camry 1999 Electrical Troubleshooting Manual

3. AUTOMATIC LIGHT CONTROL OPERATION

When the daytime running light is operating and the Automatic control sensor detects a decrease in the ambient light (It
continues less than approx. 2500 lux over about 20 seconds, and it is less than 1000 lux.), the automatic light control
operation starts. At the same time, daytime running light relay (Main) is activated, so current flows from the ALT fuse to the
Taillight relay (Coil side) to TERMINAL TAIL of the daytime running light relay (Main), and the DRL NO.2 fuse to the DRL
NO.4 relay (Coil side) to TERMINAL H–ON of the daytime running light relay (Main), activating both the Taillight relay and the
DRL NO.4 relay, so that the taillights and headlights light up.
When the automatic light control sensor detects an increase in the ambient light (It continues more than approx. 1000 lux
over about 20 seconds, and it is more than approx. 2500 lux), the ignition SW is turned to off, the light control SW is turned to
HEAD position, and the automatic light control operation stops.
SERVICE HINTS
HEAD RELAY [ENGINE ROOM J/B NO.2]
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 lever is released (Parking brake SW off)
TAILLIGHT RELAY [INSTRUMENT PANEL J/B]
5–3 : Closed with the light control SW at TAIL or HEAD position
D6 DAYTIME RUNNING LIGHT RELAY (MAIN)
2–GROUND : Approx. 12 volts with the ignition SW at ON position
5, 7,17–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 lever is released
(Parking brake SW off)
6,15–GROUND : Always approx. 12 volts
8–GROUND : Continuity with the parking brake lever pulled up
11–GROUND : 13.9–15.1 volts with the engine running at 2000 rpm 25°C (77°F)
12–GROUND : Approx. 12 volts with the high beam light up
13–GROUND : Always continuity
16–GROUND : Continuity with the dimmer SW at HIGH or FLASH position
18–GROUND : Continuity with the brake fluid level not enough
: PARTS LOCATION
Code See Page
A40 30
26 (1MZ–FE)
B2 B2
28 (5S–FE)
C9 B 30
C10 C 30
C13 30
26 (1MZ–FE)
D2 D2
28 (5S–FE)
D6 30
26 (1MZ–FE)
F4 F4 A A
28 (5S–FE)
Code See Page
26 (1MZ–FE)
F6 F6 C C
28 (5S–FE)
26 (1MZ–FE)
F9 F9 F F
28 (5S–FE)
26 (1MZ–FE)
G2 G2
28 (5S–FE)
26 (1MZ–FE)
H1 H1
28 (5S–FE)
26 (1MZ–FE)
H2 H2
28 (5S–FE)
I17 30
Code See Page
J1 31
J2 31
J4 31
J5 31
J7 31
J11 31
J27 A 31
J28 B 31
P3 31