Fuel Cut-Off Relay; Fuel Pump Inspection - Honda Motorcycle Service Manual

FUEL CUT-OFF RELAY
I
with ignition switch ON
-
-
- - -
- - -
- - - -
- -
-
-
3
With the ignition switch ON, current flows to the transistor
and thyristor, but it does not flow to the fuel pump.
To fill the carburetor float chamber with fuel when the igsition
switch is turned ON, certain fuel cut-off relays have a timer
function that sends current to the fuel pump for a few sec-
onds.
BATTERY
To
IGNITION
CONTROL
MODULE
I
I
I
I
circuit operates properly.
INSPECTION
While the engine is running, pulses are transmitted from the
ignition control module to the ignition primary circuit and,
when it is transmitted to the transistor, current flowsfrom the
transistor to the thyristor to turn it ON. The battery current
flows t o the fuel pump this way.
As the fuel cut-off relay is controlled by the ignition primary
circuit, the relay does not operate unless the ignition primary
Turn the ignition switch ON and perform the following
inspections.
with engine running
,-----------
TO BATTERY
To
IGNITION
CONTROL
MODULE
I
1. Check for battery voltage between the black wire
I+)
of the
fuel cut-off relay connector (pump connector if the relay is
built in the pump) and ground
(-1.
4
Battery voltage
I
No battery voltage
t
.
Broken black wire
Faulty sub-fuse
.
Faulty ignition switch
.
Poor connection of the
fuse holder connector
2. Check for coJtinuity between the blacklblue wire of the
relay connector and ground (or blacklyellow wire and green
wire of the pump connector, if the relay is built into the
pump).
I
I
C .
No continuity
t
Continuity
i
C
.
Faulty fuel cut-off relay
(pump)
3. Disconnect the relay, the short the black and black/blue
wires of the relay connector with a jumper wire and check
for battery voltage between the blacklblue ( + ) wire and
green wire of the pump connector.
+
No battery voltage
i
Battery voltage
C
+
-
Broken green or black/
.
.Faulty fuel pump
blue wire
+
To FUEL PUMP
IGNITION MAlN
FUSE SWITCH
FUEL CUT-OFF RELAY
- - - - -
-
L----
i
BliBu
TO IGNITION
-
CIRCUIT
IGNITION MAlN
ICM CIRCUIT
Faulty ground
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25-1 0
Date of Issue: March. 1995
0
HONDA MOTOR CO.,LTD.