4
4-13
Fuel System (EFI)
INTRODUCTION
The Arctic Cat EFI System operates off a series of coils
located on the stator and is made up of the following
components.
1. An electrical control unit (ECU) calculates input
from sensors (air temperature sensor, coolant tem-
perature sensor, throttle position sensor, ignition tim-
ing sensor (2-stroke), barometric pressure sensor (2-
stroke), and on the 800/1100 cc turbo models, a
knock sensor) to provide the engine with the correct
fuel mixture and timing for optimum operation.
2. Charge coils (1 and 2), located on the stator, provide
AC voltage to the ECU/CCU/regulator/rectifier
where AC voltage is converted to DC voltage.
3. A fuel pump coil located on the stator operates the
low voltage, high output fuel pump. At cranking
speed, the high output fuel pump provides enough
fuel to charge the fuel rail.
4. An injector coil located on the stator provides the injec-
tors with DC voltage for operation through the ECU.
5. A lighting coil located on the stator plate provides
output to the CCU (500 cc) or regulator/rectifier (800
cc) to operate accessories and the lighting system.
FLOODED ENGINE
If the engine should become flooded, set the brake lever
lock, compress the throttle lever to the full-open position,
and crank the engine over until it starts and clears itself.
Release the brake lever lock.
FUEL SYSTEM
The fuel is first drawn into the electric fuel pump through
multiple pick-up valves and hoses. The fuel is then
routed through a high-pressure fuel hose to the fuel rail.
The fuel pressure is maintained in the fuel rail by the fuel
regulator. With the fuel pressure maintained at a constant
psi, the ECU evaluates the information it receives from
the electrical sensors and opens the injectors for precise
periods of time (pulse widths) to meet engine demands.
NOTE: The entire EFI system depends on all coils
functioning properly on the stator.
Individual Components
ECU
The ECU is the brain of the EFI system. It uses sensor
inputs to determine the correct fuel/air ratio for the engine
given the existing conditions of altitude and temperature.
If any of the sensors should fail while the engine is run-
ning, the ECU will sense a problem and go into a “fail
safe” mode. This is an over-rich condition and will greatly
reduce performance. However, the engine will be pro-
tected from a possible lean condition and engine damage.
The ECU is equipped with a self-diagnostic system uti-
lizing the service icon in the speedometer/tachometer and
remains illuminated when a problem exists with any of
the sensors. The technician can determine the problem
sensor by reading the code shown on the readout screen
and applying it to the ECU Diagnostic Codes chart (see
Self-Diagnostic System/Codes in this section).
NOTE: The ECU cannot be repaired.
On 2-stroke models if the ECU is not receiving current
from one of the output coils on the stator, that circuit will
not operate. Coils on the stator are the charge coils operat-
ing the ECU, the injector coil which operates the injectors,
the fuel pump coil which operates the fuel pump, and the
lighting coil/chassis control unit operating all accessories
and the lighting system.
NOTE: On the 500 cc, the ECU is coded with a letter (A-
B-C). On the 800 cc, the ECU is coded with symbols (
-
-
). When replacement of the ECU is necessary, the
ECU must be replaced with an ECU of the same code.
Removing (800 cc)
1. Remove the expansion chamber.
2. Remove the two torx-head screws securing the rear
portion of the ECU heat shield; then remove the
shield.
3. Disconnect the wire harness leads from the ECU;
then remove the two cap screws securing the ECU.
Remove the ECU.
Installing (800 cc)
1. Secure the ECU to the chassis using the existing cap
screws; then connect the wiring harness to the ECU.
2. Secure the front of the ECU heat shield into the tabs;
then secure the back of the ECU heat shield using the
existing torx-head screws. Install the expansion
chamber.
NOTE: Make sure all connectors are clean and tight.
Apply dielectric grease to all connectors.
Removing (Bearcat/F-Series/T-
Series)
1. Disconnect the wiring harness lead from the ECU.
2. Remove the two screws securing the ECU to the left-
front upper frame; then remove the ECU.
Installing (Bearcat/F-Series/T-Series)
Secure the ECU to the left-front upper frame with the
screws; then connect the wiring harness to the ECU.
NOTE: Make sure all connectors are clean and tight.
Apply dielectric grease to all connector seals.
Removing (F/M/XF 1100 cc)
1. Remove the left-side access panel; then remove the
retaining ring securing the lower console.
2. Remove the two wiring connectors from the ECU;
then remove the ECU mounting bracket from the
rear belt guard.
Summary of Contents for Sno Pro 120
Page 20: ...1 18 NOTES ...
Page 29: ...2 9 2 570ENG12 ...
Page 39: ...2 19 2 500CC2A_12 ...
Page 45: ...2 25 2 NOTES ...
Page 47: ...2 27 2 800_12_2 ...
Page 61: ...2 41 2 Engine Torque Patterns 1100 cc 1100TorquePattern12 ...
Page 63: ...2 43 2 1100ccZ1RV10 ...
Page 81: ...2 61 2 1100ccZ1RV10 ...
Page 82: ...2 62 Engine Torque Patterns 1100 cc 1100TorquePattern12 ...
Page 141: ...2 121 2 SNO2152 ...
Page 142: ...2 122 SNO2153 ...
Page 180: ...3 18 0742 314 0746 520 F5 LXR 800 cc ...
Page 204: ...3 42 NOTES ...
Page 260: ...5 26 Troubleshooting Servomotor SERVO1A12 ...
Page 261: ...5 5 27 SERVO2rv ...
Page 264: ...Magneto 0746 255 1 ...
Page 266: ...Main Harness p n 1686 603 F5 LXR 0746 249 3 ...
Page 269: ...Main Harness p n 1686 588 F 800 M 800 XF 800 0746 242 6 ...
Page 270: ...Main Harness p n 1686 611 TZ1 Turbo LXR LTD 0746 253 7 ...
Page 271: ...Main Harness p n 1686 610 TZ1 TZ1 LXR 0746 252 8 ...
Page 272: ...Main Harness p n 1686 613 Bearcat Z1 XT GS p n 1686 615 Bearcat Z1 XT LTD 0746 511 9 ...
Page 273: ...Main Harness p n 1686 578 Sno Pro 120 10 0744 204 ...
Page 274: ...Ignition Main Harness p n 1686 628 Sno Pro 500 11 0745 605 ...
Page 275: ...Ignition Main Harness p n 1686 657 Sno Pro 600 12 0746 250 ...
Page 276: ...0745 601 13 Console Harness p n 1686 631 TZ1 LXR TZ1 Turbo LXR LTD ...
Page 277: ...Hood Harness p n 1686 638 F 800 M 800 XF 800 0746 243 14 ...
Page 278: ...Console Harness p n 1686 633 Bearcat 570 F570 T570 0746 238 15 ...
Page 279: ...Console Harness p n 1686 634 F5 LXR 0746 240 16 ...
Page 280: ...Hood Harness p n 1686 639 F 1100 Turbo M 1100 Turbo HCR XF 1100 Turbo 0746 246 17 ...
Page 282: ...0746 254 19 Console Harness p n 1686 547 Bearcat Z1 XT GS p n 1686 549 Bearcat Z1 XT LTD TZ1 ...
Page 283: ...Hood Harness p n 1686 587 Sno Pro 500 20 0744 201 ...
Page 285: ...Passenger Seat Harness p n 1686 570 22 0744 197 ...
Page 286: ...Handlebar Harness p n 1686 636 F 800 M 800 XF 800 p n 1686 654 M 800 HCR 0746 244 23 ...
Page 287: ...Handlebar Harness p n 1686 537 Bearcat 570 F570 T570 0746 239 24 ...
Page 288: ...Handlebar Harness p n 1686 574 F5 LXR 0744 189 25 ...
Page 289: ...Handlebar Harness p n 1686 637 F 1100 Turbo M 1100 Turbo XF 1100 Turbo 0746 247 26 ...
Page 290: ...Handlebar Harness p n 1686 590 Sno Pro 500 27 0744 200 ...
Page 291: ...Handlebar Harness p n 1686 656 M 1100 Turbo Sno Pro HCR 28 0746 510 ...
Page 292: ...Misc Groomer Special p n 1686 645 p n 1686 646 p n 1686 647 p n 1686 648 29 0746 241 ...
Page 460: ...8 26 0744 930 ...