Snowmobile Arctic Cat (2008 year). Manual - part 76

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„NOTE: With the Arctic Cat EFI System, it is
extremely important that the ECU receives the
proper current output from four coils (two charge
coils, an injector coil, and a fuel pump coil) to
function as designed. If a problem exists, these
coils should be checked using the following proce-
dures.

Charge Coil (1)/Charge Coil (2) 

Resistance Test

The charge coils power the ECU. To test these coils,

disconnect the 3-wire connector from the ECU to the

stator.

1. Set the meter selector to the OHMS scale and test

between the black/red and green/red wires (coil 1).

2. The meter must show 7.20-10.8 ohms. 

3. Test between the green/red and brown/white wires

(coil 2). 

4. The meter must show 7.20-10.8 ohms.

„NOTE: If either test is not within specifications,
the stator must be replaced. Refer to the wiring
diagram.

Injector Coil Resistance Test

The injector coil located on the stator powers the two

injectors.

1. Disconnect the double-wire plug with two blue/

white leads from the stator to the ECU.

2. Set the meter selector to the OHMS scale.

3. Connect a meter lead to each of the blue/white

leads. The meter must show 15.2-22.8 ohms.

„NOTE: If reading is not within the specification,
recheck to confirm test results. If still out of toler-
ance, replace the stator.

„NOTE: If the resistance test is good, a peak
reading voltage test should also be made. Refer to
Peak Voltage Tests in Section 5.

Fuel Pump Coil Resistance Test

The fuel pump coil powers the fuel pump through the

ECU.

„NOTE: With the engine running, there should
12.3-12.9 DC volts supplied to the fuel pump for
operation. To test fuel pump coil resistance, use
the following procedure.

1. Disconnect the double-plug with the two orange

wires from the ECU.

2. Set the meter selector to the OHMS scale. Connect

a meter lead to each of the two orange leads.

3. The meter must show 1.52-2.28 ohms.

„NOTE: If reading is out of tolerance, recheck to
confirm reading. If still out of tolerance, replace
the stator.

„NOTE: If the resistance test is good, a peak
reading voltage test should also be made. Refer to
Peak Voltage Tests in Section 5.

Lighting Coil Resistance Test

The lighting coil located on the stator provides AC

power to the lighting system and accessories through

the chassis control unit. To test the lighting coil resis-

tance, follow this procedure.

1. Disconnect the 3-wire connector at the engine.

2. Set the meter selector to the OHMS scale.

3. Test between the two yellow leads.

4. The meter must show 0.8-0.12 ohm.

„NOTE: If reading is out of tolerance, recheck to
confirm reading. If still out of tolerance, replace
the stator.

ACTIVATING ECU MEMORY

1. Connect the analyzer test harness to the ECU diag-

nostic connector.

2. Connect the analyzer test harness red and black

leads to a 12-volt battery.

3. Turn the analyzer switch ON.

4. Press the analyzer MENU SELECT buttons

repeatedly until KOKUSAN appears on the dis-

play. Once the word KOKUSAN appears on the

display, press the TEST button. The analyzer is

now set up to test the EFI system.

5. Press the analyzer MENU SELECT buttons

repeatedly until the words Memory Problem Diag-

nosis Test appears on the display.

6. Press the analyzer TEST button. If all sensors are

good, SENSORS ALL O.K. will appear on the

display. If any of the sensors have intermittently

failed or are faulty, they will appear on the display.

Proceed then to checking the faulty sensor individ-

ually as covered in this section.

„NOTE: Once problem areas have been deter-
mined, always check the component(s) for clean
and tight connections.

Memory Problem Diagnosis Test

4

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7. To erase the memory of the ECU, press the TEST

button once again; then push the MENU SELECT

buttons until Diagnosis Memory Clear appears on

the display. Turn the analyzer OFF and then back

ON again. Reselect KOKUSAN mode; then pro-

ceed to the Memory Problem Diagnosis Test and

push the TEST button. The display should indicate

SENSORS ALL O.K. which indicates the memory

has been cleared.

REMOVING ECU

1. Disconnect the wiring harness lead from the ECU.

2. Remove the two screws securing the ECU to the

air-intake silencer (Crossfire/M-Series) or to the

left-front upper frame (F-Series/T-Series).

3. Remove the ECU.

INSTALLING ECU

1. Secure the ECU to the air-intake silencer (Cross-

fire/M-Series) or to the left-front upper frame (F-

Series/T-Series) with the screws.

„NOTE: On the Crossfire/M-Series, make sure the
diagnostic connector plug faces the oil reservoir.

2. Connect the wiring harness to the ECU.

„NOTE: Make sure all connectors are clean and
tight. Apply dielectric grease to all connectors.

Testing Individual 

Components

„NOTE: For individual resistance testing proce-
dures, see Section 5 in this manual.

„NOTE: For the following tests, use the Fluke
Model 73 Multimeter or a multimeter of the same
quality.

THROTTLE POSITION SENSOR 

If the snowmobile is under warranty, the throttle posi-

tion sensor on the EFI system is not a serviceable part.

If the sensor should malfunction, the complete throttle

body assembly must be replaced.

„NOTE: If the snowmobile is in warranty, break-
ing the seal on the idle screw jam nut or the Phil-
lips-head screws on the TPS will void warranty.

„NOTE: It is important to order a throttle body
assembly with the same symbol marking on the
injectors as the ones being replaced. The symbol
is located on the side of the injector top.

FUEL INJECTORS

FS021

Testing Resistance

1. Disconnect the fuel injector wiring harness.

2. Set the meter selector to the OHMS scale.

3. Test between the two injector terminals. Test spec-

ification is 2.4-3.3 ohms.

CM039

4. If not within specifications, replace the injector.

Removing

1. Loosen the clamp securing the fuel supply hose to

the fuel rail; then remove the hose from the fuel

rail.

2. Disconnect the wiring harness from each injector.

3. Remove the screws securing the injector hold-

down plate to the throttle body assembly; then

remove the plate from the injectors.

4. Remove the fuel injectors from the throttle body/

intake manifold assembly.

! CAUTION

The fuel supply hose may be under pressure. Place
an absorbent towel around the connection to absorb
fuel; then remove the hose slowly to release the
pressure.

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CM203A

Installing

1. Apply a light coat of oil to all O-rings; then install

the upper and lower O-rings onto each injector.

2. Install the injectors into the throttle body assem-

bly.

3. Place the injector hold-down plate into position on

top of the injectors and secure with two screws.

4. Connect the fuel delivery hose to the fuel rail and

secure with a clamp.

„NOTE: When securing the fuel delivery hose,
position the clamp as shown.

0729-325

5. Connect the wiring harness to the injectors making

sure the number 1 harness is connected to the

MAG-side injector.

IGNITION TIMING SENSOR

0729-627

Testing Resistance

1. Disconnect the two leads from the sensor to the

main wiring harness.

2. Set the meter selector to the OHMS scale.

3. Test between the green/white and brown leads

from the sensor. Test specification is 152-228

ohms.

„NOTE: This sensor is located inside the mag-
neto case next to the flywheel, and the recoil
starter and the flywheel must be removed to
access the sensor (see Section 2).

ELECTRIC FUEL PUMP

1. Remove the hardware securing the console to the

gas tank and frame; then move the console out of

the way.

2. Disconnect the fuel pump from the main wiring

harness.

3. Connect the positive lead of a 12-volt power sup-

ply to the red wire and the negative lead of the 12-

volt power supply to the black wire.

4. The pump should operate (it would be heard run-

ning).

„NOTE: If the fuel pump fails to operate, the
pump is defective and must be replaced.

TESTING FUEL PRESSURE 
REGULATOR 

1. Using the Fuel Pressure Test Kit, connect the

tester to the regulator fuel inlet.

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AO053

„NOTE: A short piece of 3/8 in. I.D. hose will be
needed to make the above connections.

2. Pressurize the regulator to 2.0-2.2 kg/cm² (28-31.3

psi). Turn the pressure tester shut off valve to the

OFF position. Observe the gauge for several min-

utes and note if there is any loss of pressure. If

pressure begins to drop, the cause may be a rup-

tured diaphragm, worn spring, or leaking valve. If

the regulator fails to build or maintain pressure,

replace the regulator.

„NOTE: If there is a drop in pressure, check the
hose connections to ensure there are no leaks.

COOLANT TEMPERATURE SENSOR

Testing Resistance

„NOTE: The coolant temperature sensor is very
sensitive to temperature change. Before the resis-
tance test is conducted, it is important to know the
coolant temperature. If the engine has been oper-
ated recently and the coolant is warm, the resis-
tance will measure lower than if the coolant was at
room temperature or colder. For accurate test
results, check the coolant temperature in the filler
neck using a thermometer.

1. Disconnect the coolant temperature sensor wiring

harness from the main harness.

2. Set the meter selector to the OHMS position and

test the resistance between the two leads from the

sensor.

3. Compare the resistance reading to the EFI Compo-

nent Voltage/Resistance Chart - Water Tempera-

ture in this sub-section. If resistance is not within

the specification, replace the sensor.

„NOTE: A coolant temperature sensor voltage
test can be made using the EFI Analyzer. 

„NOTE: The coolant temperature sensor is
located at the lower half of the crankcase. To
remove the sensor, the engine must be removed
(see Section 2).

INTAKE AIR TEMPERATURE 
SENSOR

Testing Resistance

„NOTE: It is very important to know the compo-
nent temperature before conducting this test.
Allow the engine to reach room temperature.

1. Disconnect the wiring harness from the intake air

temperature sensor.

AO135D

2. Set the meter selector in the OHMS position and

test the two leads located in the sensor connector.

Compare with the EFI Component Voltage/Resis-

tance Chart - Air Temperature in this sub-section.

„NOTE: The intake air temperature sensor
employs a thermistor, which is very sensitive to
temperature changes. Resistance will change as
temperature varies.

Removing

1. Disconnect the wiring harness from the intake air

temperature sensor.

2. Using a standard screwdriver, pry the sensor end

to end to remove it from the air-intake silencer.

Account for two push pins.

Installing

1. Place the sensor into position in the air-intake

silencer and secure with push pins.

2. Connect the wiring harness to the intake air tem-

perature sensor. Secure the sensor leads with cable

ties so they do not rub on any other components.