165
Fuel System
Fuel System Tests
7
Vapor Vent Solenoid Circuit Test
Remove the electrical connector from the vapor
vent solenoid.
Use the diode test function of a digital multimeter
with appropriate test probe leads to check the sig-
nal circuit.
Connect the negative meter lead to the wire listed
in the table, connect the positive meter lead to
engine ground.
Results:
• No reading (OL or ∞) indicates an open circuit.
• A reading of zero (0) indicates an short circuit.
Isolate the faulty component. Check wiring and
connections. Repair or replace faulty wiring.
Use a digital multimeter with appropriate test
probe leads to measure the resistance of the
vapor vent solenoid ground circuit.
Connect the positive meter lead to the engine har-
ness connector wire listed in the table. Connect
the negative meter lead to engine ground.
Results:
• An infinite reading (∞) indicates an open circuit.
Isolate the faulty component. Check wiring and
connections. Repair or replace faulty wiring.
Electric Fuel Lift Pump Resistance Test
Disconnect the battery cables at the battery.
Remove the electrical connector from the fuel
pump and vapor separator assembly.
Use a digital multimeter with appropriate test
probe leads to measure the fuel pump coil resis-
tance.
Connect the black meter lead to the black wire,
connect the red meter lead to the red wire.
Electric Fuel Pump Circuit Test
Remove the electrical connector from the fuel
pump and vapor separator assembly.
Use the diode test function of a digital multimeter
with appropriate test probe leads to check the sig-
nal circuit.
Connect the negative meter lead to the wire listed
in the table, connect the positive meter lead to
engine ground.
Results:
• No reading (OL or ∞) indicates an open circuit.
• A reading of zero (0) indicates an short circuit.
Isolate the faulty component. Check wiring and
connections. Repair or replace faulty wiring.
Vapor Vent Solenoid Circuit Diode Test
Wire Pin Result
BROWN/YELLOW 1
approximately
0.5 VDC
Vapor Vent Solenoid
Ground Circuit Resistance
Wire Pin Result
BLACK 2 < 1 Ω
Fuel Pump Resistance
<10 Ω @ 77°F (25°C)
Fuel Pump Circuit Diode Test
Wire Pin Result
BROWN/WHITE 3
approximately
0.5 VDC
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