Headlamp Control Module: Description and Operation
SYSTEM OUTLINEWith the ignition SW turned on, the current flows to TERMINAL (A) 5 of the body ECU through IG1 fuse.
Voltage is applied at all times to TERMINAL (A) 7 of the body ECU through the TAILLIGHT relay. Coil side, and to TERMINAL (C) 3 through the HEAD LAMP relay coil side (w/o daytime running light) or through the DRL NO.2 relay (w/ daytime running light).
1. NORMAL LIGHTING OPERATION
With the light control SW turned to TAIL position, a signal is input into TERMINAL (B) 18 of the body ECU. Due to this signal, the current flowing to TERMINAL (A) 7 of the body ECU flows to TERMINAL (B) 18 to TERMINAL 14 of the light control SW to TERMINAL 16 to GROUND, and TAILLIGHT relay causes taillights to turn on.
With the light control SW turned to HEAD position, a signal is input into TERMINALS (B) 17 and (B) 18 of the body ECU. Due to this signal, the current flowing to TERMINAL (C) 3 of the body ECU flows to TERMINAL (B) 17 to TERMINAL 13 of the light control SW to TERMINAL 16 to GROUND in the headlight circuit, and causes TAILLIGHT and HEAD LAMP (w/o daytime running light) or DRL NO.2 relay (w/ daytime running light) to turn the lights on. The taillight circuit is same as above.
2. LIGHT AUTO TURN OFF OPERATION
With light on and ignition SW turned off (Input signal goes to TERMINAL (A) 5 of the body ECU), when the driver's door is opened (Input signal goes to TERMINAL (C) 11 of the body ECU), the ECU operates and the current is cut off which flows from TERMINAL (A) 7 of the body ECU to TERMINAL (B) 18 in taillight circuit and from TERMINAL (C) 3 to TERMINAL (B) 17 in headlight circuit.
As a result, all lights are turned off automatically.