Main Relay Control; Fuel Pump Relay Control - Suzuki F6A Service Manual

MAIN RELAY CONTROL

The main relay supplies battery voltage to the ECM according to the ON/OFF status of the ignition switch.
When the ignition switch is turned ON, the coil of the relay is ground, and thereby the relay switch circuit is closed.
By this means, battery voltage is applied to the "+B" terminal, and the EFI system is activated.
Further, the output circuit of the relay supplies battery voltage to the following actuators and sensors.
Actuators and servers using the main relay as a power source
Injectors
Vehicle speed sensor
The circuit of the relay coil is connected to a ground via a diode in the ECM, and prevents current from running through
the coil in the unlikely event of reverse connection of the battery.
+12V (BAT.)
IGSW
COLOR CODE
B – BLACK
ST
R – RED
G – GREEN
W – WHITE
GY – GRAY

FUEL PUMP RELAY CONTROL

The ON/OFF control of the fuel pump is performed by the ECM controlling the fuel pump relay (controlling current
flowing to the relay coil part). When the relay is ON, battery voltage is applied to the fuel pump, and the pump is operated.
The fuel pump operates under the following conditions.
IG1
COLOR CODE
B – BLACK
PK – PINK
BL – BLUE
W – WHITE
G – GREEN
112
ISC valves
Radiator fan relay (coil side)
MAIN RELAY
B/R
GY/W
IG1
+12V
(VIA MAIN RELAY)
R/B
FUEL PUMP
RELAY
W/G
FUEL PUMP
Crank angle sensor
Fuel Pump
ECM
201 12V
+B
RG
207
ECM
B/BL
4 FPR
PK/B
M
9 E01
B/BL
E02
B 17