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Fuel System
Fuel System Tests
7
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 fuel
level switch 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.
Fuel Injector Resistance Test
Disconnect the battery cables at the battery.
Remove the electrical connector from the fuel
injector.
Use a digital multimeter with appropriate test
probe leads to measure the injector coil resis-
tance.
Fuel Injector Circuit Test
Remove the electrical connector from the fuel
injector.
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 fuel
injector 55V circuit.
Connect the positive meter lead to the engine har-
ness connector wire listed in the table. Connect
the negative meter lead to the red/white wire of a
known good circuit such as an oil pump.
Results:
• An infinite reading (∞) indicates an open circuit.
Isolate the faulty component. Check wiring and
connections. Repair or replace faulty wiring.
Fuel Level Switch
Ground Circuit Resistance
Wire Pin Result
BLACK 4 < 1 Ω
Fuel Injector Coil Resistance
2 to 3 Ω
@ 72°F (22°C)
Fuel Injector Signal Circuit Diode Test
Wire Pin Result
BLUE 2
approximately
0.5 VDC
PURPLE 2
GREEN 2
Fuel Injector 55V Circuit Resistance
Wire Pin Result
WHITE/RED 1 < 1 Ω
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