Snowmobile Yamaha FX10X, FX10RTX, FX10RTRX, FX10RTRAX, FX10MTX, FX10MTRX, FX10MTRAX. Manual - part 68

7-2

FI

FUEL INJECTION SYSTEM

CIRC

UIT D

IAGRA

M

R

/W

L/

W

(BLACK)

L/

W

R

/G

R

/W

L/

W

Y

Lg

G

(BLACK)

B

Br

/B

L

R

/WG

/Y

R

/G

R

/L

R

/WL

/R

R

W

Br

Br/L

Y

/R

P

/L

W

/G

R

/G

Br

/L

L

/B

O

Lg

B

G

/Y

L

/R

B

G

/B

R

/Y

Br

/L

R

/B

Gy

/R

O

/G

L

Br

/W

P

G

/W

L

/WR

/W

Gy

P

/W

R

/LC

h

Y

/L

W

L

/Y

B

/L

Y

/W

Y

/GB

/Y

Y

Lg

R

/W

L

/W

Y

/G

Lg

R

/W

L

/W

R

/W

L

/W

R

/G

Ch

Y

G

B

G

/Y

Br

/L

B

/Y

L

/Y

Lg

Y

/R

R

/Y

Gy

O

Gy

/R

O

/G

R

/B

G

/B

L

/B

B

B

L

/R

R

/L

L

Y

W

P

/W

P

G

/W

Br

/W

B

/L

R

/G

P

/L

W

/G

Br

/L

Y

/W

Y

/L

R

/BR

/L

G

/BR

/L

L

/BR

/L

B

B

HI

LO

G

B

Y

Y

G

B

G

B

Y

B

L

B

L

(BLACK)

(BLACK)

B

L/

W

Br

R

/Y

R

/W

Br

/W

Br

R

OFF

ON

START

RUN

STOP

OFF

ON

CLOSE

OPEN

Y

/L

Y

/W

Ch

Y

/WY

/L

B

/L

P

O

/R

B

/W

LW

B

/L

G

L

/R

B

LY

B

L

/W

Lg

G

L

W

/B

G

B

O

/B

L/

BG

/BR

/BR

/L

P

/W

R

/G

Y

B

/L

L

P

R

/YW

/G

Br

/L

(GRAY)

P

/L

L/

B

G

/B

R

/B

R

/L

P

/W

R

/G

Y

B

/L

L

P

/BR

/Y

W

/G

Br

/L

(GRAY)

P

/L

Y

/G

Y

/G

B

/L

Ch

(BLACK)

(BLACK)

B

/Y

B

/Y

G

L/

R

B

L/

R

G

B

L

/Y

Ch

Y

R

/B

R

/W

G

/B

R

/W

G

/B

Y

R

/B

L

/Y

Ch

G

/W

B

/L

B

/L

G

/W

Br

/W

(BLACK)

Br

Br

(BLACK)

R

/W

B

/L

(BLACK)

Gy

Gy

(BLACK)

B

R

/W

(BLACK)

O

R

/W

(BLACK)

Gy

/R

R

/W

(BLACK)

O

/G

R

/LR

/B

(GRA

Y)

R

/LG

/B

(GRA

Y)

R

/LL

/B

(GRA

Y)

B

/L

Y

L

(BLACK)

B

R

/L

R

/G

P

/L

R

/Y

(BLACK)

Br

/L

W

/G

R

/Y

G

/W

B

/L

(DARK GREEN)

Y

/G

B

W

Lg

B

L/R

G

G

L/R

B

(GREEN)

G

G

/B

Ch

Br

P

P

L/R

B

Y/R

B

B

B

Y/R

B

B

(GREEN)

(GRA

Y)

Ch

R

/B

Br

/W

B

/L

(BLACK)

L

(BLACK)

P

/W

B

/L

L

(BLACK)

P

/BB

/L

W

(GRAY)

WW

R

(BLACK)

B

R

R

R

/WG

/BL

/YR

/B

(BLACK)

Ch

Y

WIRE HARNESS

FUEL INJECTION SYSTEM

SUB-WIRE HARNESS

A

WIRE

HARNESS

OIL PRESSURE

SWITCH

SUB-LEAD

B

WIRE

HARNESS

WIRE

HARNESS

TAIL/BRAKE

 LIGHT 

SUB-LEAD

SPEEDOMETER

UNIT SUB-LEAD

C

E

WIRE

HARNESS

REVERSE SWITCH

SUB-WIRE HARNESS

F

WIRE

HARNESS

COOLANT

TEMPERATURE

SENSOR SUB-LEAD

G

L/

R

B

B

L/

R

È

É

ÈÉ

R

Gy

B

B

/L

R

/Y

L

/W

Br

B

Br
R

W

W

W

R

R

O

/B

O

/B

B

L

/W

L

/R

Br

/B

R

/Y

Br

/B

R

/W

L

B

B

R

B

B

Br

R

/W

B

/Y

Lg

Y

/R

Y

/R

B

B

B

Y

/G

R

/G

R

/L

R

/W

L

/R

R

/L

B

R

/Y

G

/W

B/L

B/L

Br/W

R

/Y

Ch

L

L

/W

L

/W

Ch

R

/B

L

/R

G

G

L/

R

B

G

/B

Ch

Ch

Ch

Ch

Lg

B

G

/Y

Br/L

W

W

W

W

R

R

Lg

R

/W

O

R

/W

Gy

/R

R

/W

O

/G

L

Y

B

/L

L

W

B

/L

R

Y

Lg

R

/W

R

/W

R

/W

Y

Y

Y

G

B

L

/Y

Y

/W

Ch

Y

/L

L

/Y

G

/B

R

/B

E

E

R

/B

R

/B

E

R

/B

A

G

/B

A

L

/B

R

/B

G

/B

L

/B

A

L

L

A

Y

Y

L

/R

L

/R

F

Y

/G

Y

/G

B

A

B

/L

B

/L

A

R

/G

R

/G

A

P

/L

P

/L

A

W

/G

W

/G

A

Br

/L

P

/W

B

/L

L

P

/B

B

/L

L

Br

/L

R

/G

P

/L

W

/G

Br

/L

A

R

/Y

A

P

/W

A

P

A

G

/W

G

B

/L

R

/Y

P

/W

P

/B

G

/W

B

/L

G

E

G

/B

L

/Y

G

/B

E

E

B

B

C

B

B

B

P

P

L

/R

B

F

G

G

C

L/

R

L/

R

C

R

/L

R

/L

A

(BLACK)

(BLACK)

Lg

EE

F

G

H

I

J

J

J

K

8

9

0

A

BC

D

1

2

3

4

5

6

7

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

[

\

]

_

a

b

c

d

e

f

g

h

h

i

j

k

l

m

n

o

p

q

r

7-3

FI

FUEL INJECTION SYSTEM

3 Crankshaft position sensor
4 Main switch
5 Main fuse
6 Load control relay
7 Battery
0 Fuel injection system fuse
B Engine stop switch
C Throttle switch
D Thumb warmer
E Grip warmer
F Oil pressure switch
G CO adjustment coupler
H ECU (engine control unit)
I Cylinder-#1 ignition coil
J Spark plug
K Cylinder-#2 ignition coil
L Cylinder-#3 ignition coil
M Fuel injection system relay
N Fuel pump
O Injector #1
P Injector #2
Q Injector #3
R Throttle position sensor
S Speed sensor
T ISC (idle speed control) unit
U Intake air pressure sensor 1 (cyl-

inders #1, #2, and #3)

V Intake air pressure sensor 2 (cyl-

inder #1)

W Coolant temperature sensor
X Intake air temperature sensor
Y Grip/thumb warmer adjustment 

switch

Z Frame ground
_ Tail/brake light
d Multi-function meter
e Warning light
h Headlight
i Headlight relay
k Radiator fan motor
l Radiator fan motor relay
n Ignition fuse
o Radiator fan motor fuse
p Signal fuse
q Headlight fuse

È FX10MT/FX10MTR/FX10MTRA

7-4

FI

FUEL INJECTION SYSTEM

ECU SELF-DIAGNOSTIC FUNCTION

The ECU is equipped with a self-diagnostic function in order to ensure that the fuel injection system is operat-
ing normally. If this function detects a malfunction in the system, it immediately operates the engine under
substitute characteristics and the warning light and self-diagnostic warning indicator on the LCD flash to alert
the rider that a malfunction has occurred in the system. Once a malfunction has been detected, a fault code is
stored in the memory of the ECU.
• If a malfunction is detected in the system by the self-diagnostic function, the ECU provides an appropriate

substitute characteristic operation, and the warning light and self-diagnostic warning indicator on the LCD
flash to alert the rider of the detected malfunction.

• The lowest fault code number appears on the odometer/tripmeter/engine speed meter LCD. Once a fault

code has been displayed, it remains stored in the memory of the ECU until it is deleted.

SELF-DIAGNOSTIC FUNCTION TABLE

If the ECU detects an abnormal signal from a sensor while the snowmobile is being driven, the warning light
and self-diagnostic warning indicator on the LCD flash to alert the rider that a malfunction has occurred and
the ECU provides the engine with alternate operating instructions that are appropriate for the type of malfunc-
tion.
When an abnormal signal is received from a sensor, the ECU processes the specified values that are pro-
grammed for each sensor in order to provide the engine with alternate operating instructions that enable the
engine to continue to operate or stop operating, depending on the conditions.
Self-Diagnostic-Function table

Fault code 

No.

Item

Symptom

Able/unable 

to start

Able/unable 

to drive

12

Crankshaft position sensor

No normal signals are received from the 
crankshaft position sensor.

Unable

Unable

13

Intake air pressure sensor 1 (cylinders #1, 
#2, and #3) (open or short circuit)

Intake air pressure sensor: open or short 
circuit detected.

Able

Able

14

Intake air pressure sensor 1 (cylinders #1, 
#2, and #3) (hose line)

Intake air pressure sensor: hose system 
malfunction (clogged or detached hose).

Able

Able

15

Throttle position sensor (open or short cir-
cuit)

Throttle position sensor: open or short cir-
cuit detected.

Able

Able

16

Throttle position sensor (stuck)

Stuck throttle position sensor detected.

Able

Able

21

Coolant temperature sensor

Coolant temperature sensor: open or short 
circuit detected.

Able

Able

22

Intake air temperature sensor

Intake air temperature sensor: open or 
short circuit detected.

Able

Able

25

Intake air pressure sensor 2 (cylinder #1) 
(open or short circuit)

Intake air pressure sensor: open or short 
circuit detected.

Able

Able

26

Intake air pressure sensor 2 (cylinder #1) 
(hose line)

Intake air pressure sensor: hose system 
malfunction (clogged or detached hose).

Able

Able

30

Oil pressure dropped

Engine stops when an oil pressure drop is 
detected.

Unable

Unable

33

Cylinder-#1 ignition coil (faulty ignition)

Malfunction detected in the primary lead of 
the cylinder-#1 ignition coil.

Able 

(depending 

on the num-

ber of faulty 

cylinders)

Able 

(depending 

on the num-

ber of faulty 

cylinders)

34

Cylinder-#2 ignition coil (faulty ignition)

Malfunction detected in the primary lead of 
the cylinder-#2 ignition coil.

Able 

(depending 

on the num-

ber of faulty 

cylinders)

Able 

(depending 

on the num-

ber of faulty 

cylinders)

35

Cylinder-#3 ignition coil (faulty ignition)

Malfunction detected in the primary lead of 
the cylinder-#3 ignition coil.

Able 

(depending 

on the num-

ber of faulty 

cylinders)

Able 

(depending 

on the num-

ber of faulty 

cylinders)

7-5

FI

FUEL INJECTION SYSTEM

Communication error with the meter

37

ISC (idle speed control) valve (stuck fully 
open)

Engine speed is high when the engine is 
idling.

Able

(unable if 

valve stuck 

fully closed)

Able

42

Speed sensor

No normal signals are received from the 
speed sensor.

Able

Able

43

Fuel system voltage (monitor voltage)

Power supply to the fuel injectors and fuel 
pump is not normal.

Able or 

unable 

depending on 

the condi-

tions 

Able or 

unable 

depending on 

the condi-

tions 

44

Error in writing the amount of CO adjust-
ment on EEPROM

Error is detected while reading or writing on 
EEPROM (CO adjustment value).

Able

Able

46

Snowmobile system power supply (monitor 
voltage)

Power supply to the ECU is not normal.

Able

Able

50

ECU internal malfunction (memory check 
error)

Faulty ECU memory. (When this malfunc-
tion is detected in the ECU, the fault code 
number might not appear on the meter.)

Unable

Unable

81

Grip warmer

Grip warmer: open or short circuit detected.

Able

Able

83

Thumb warmer

Thumb warmer: short circuit detected.

Able

Able

84

T.O.R.S.

Conditions requiring T.O.R.S. operation are 
detected.

Able

Unable

85

Oil pressure switch

Oil pressure switch: open circuit detected.

Able

Able

Fault code 

No.

Item

Symptom

Able/unable 

to start

Able/unable 

to drive

Er-1

ECU internal malfunction (output signal 
error)

No signals are received from the ECU.

Unable

Unable

Er-2

ECU internal malfunction (output signal 
error)

No signals are received from the ECU 
within the specified signal time.

Unable

Unable

Er-3

ECU internal malfunction (output signal 
error)

Data from the ECU cannot be received cor-
rectly.

Unable

Unable

Er-4

ECU internal malfunction (input signal 
error)

Non-registered data has been received 
from the meter.

Unable

Unable

Fault code 

No.

Item

Symptom

Able/unable 

to start

Able/unable 

to drive