Kawasaki Ninja 300 / Ninja 300 ABS Motorcycle. Service Manual (2013)

3-20 FUEL SYSTEM (DFI)

Specifications

Item

Standard

Subthrottle Sensor:

Input Voltage

DC 4.75

∼

5.25 V

Output Voltage

DC 0.78

∼

0.82 V at subthrottle valve full close

position
DC 3.9

∼

4.5 V at subthrottle valve full open position

(for reference)

Resistance

∼

6 k

Ω

Subthrottle Valve Actuator:

Resistance

About 5.2

∼

7.8

Ω

Input Voltage

About DC 11.5

∼

13.5 V

Oxygen Sensor (Equipped Models):

Output Voltage (Rich)

DC 0.7 V or more

Output Voltage (Lean)

DC 0.2 V or less

Heater Resistance

11.7

∼

15.5

Ω

at 20°C (68°F)

Purge Valve (CAL Model):

Resistance

∼

Ω

at 20°C (68°F)

Throttle Grip and Cables

Throttle Grip Free Play

∼

3 mm (0.08

∼

0.12 in.)

Air Cleaner

Element

Polyurethane foam

FUEL SYSTEM (DFI) 3-23

DFI Servicing Precautions

There are a number of important precautions that should

be followed servicing the DFI system.

○

This DFI system is designed to be used with a 12 V sealed
battery as its power source. Do not use any other battery
except for a 12 V sealed battery as a power source.

○

Do not reverse the battery cable connections. This will
damage the ECU.

○

To prevent damage to the DFI parts, do not disconnect the
battery cables or any other electrical connections when
the ignition switch is on or while the engine is running.

○

Take care not to short the cables that are directly con-
nected to the battery positive (+) terminal to the chassis
ground.

○

When charging, remove the battery from the motorcycle.
This is to prevent ECU damage by excessive voltage.

○

Whenever the DFI electrical connections are to be dis-
connected, first turn off the ignition switch, and disconnect
the battery (–) terminal. Do not pull the lead, only the con-
nector. Conversely, make sure that all the DFI electrical
connections are firmly reconnected before starting the en-
gine.

○

Connect these connectors until they click [A].

○

Do not turn the ignition switch on while any of the DFI
electrical connectors are disconnected. The ECU memo-
rizes service codes.

○

Do not spray water on the electrical parts, DFI parts, con-
nectors, leads, and wiring.

○

If a transceiver is installed on the motorcycle, make sure
that the operation of the DFI system is not influenced by
electric wave radiated from the antenna. Check operation
of the system with the engine at idle. Locate the antenna
as far as possible away from the ECU.

○

When any fuel hose is disconnected, fuel may spout out
by residual pressure in the fuel line. Cover the hose joint
with a piece of clean cloth to prevent fuel spillage.

○

When any fuel hose is disconnected, do not turn on the
ignition switch. Otherwise, the fuel pump will operate and
fuel will spout from the fuel hose.

○

Do not operate the fuel pump if the pump is completely
dry. This is to prevent pump seizure.

○

Before removing the fuel system parts, blow the outer sur-
faces of these parts clean with compressed air.

○

To prevent corrosion and deposits in the fuel system, do
not add to fuel any fuel antifreeze chemicals.

FUEL SYSTEM (DFI) 3-25

Troubleshooting the DFI System

Outline

When a problem occurs with DFI system, the yellow en-

gine warning indicator light (LED) [A] goes on or blinks to
alert the rider. In addition, the condition of the problem is
stored in the memory of the ECU.

With the engine stopped and turned in the self-diagnosis

mode, the service code [A] is displayed on the LCD (Liquid
Crystal Display) by the number of two digits.

If the problem is with the following parts, the ECU can

not recognize these problem. Therefore, the yellow engine
warning indicator light (LED) does not go on, and service
code is not displayed.

LCD for Meter Unit
Fuel Pump
Fuel Pump Relay
Fuel Injectors
Stick Coil Secondary Wiring and Ground Wiring
ECU Main Relay
ECU Power Source Wiring and Ground Wiring

When the service code [A] is displayed, for first ask the

rider about the conditions [B] of trouble, and then start to
determine the cause [C] of problem.

As a pre-diagnosis inspection, check the ECU for ground

and power supply, the fuel line for no fuel leaks, and for
correct pressure. The pre-diagnosis items are not indicated
by the yellow engine warning indicator light (LED).

Don’t rely solely on the DFI self-diagnosis function, use

common sense.

3-26 FUEL SYSTEM (DFI)

Troubleshooting the DFI System

Even when the DFI system is operating normally, the yel-

low engine warning indicator light (LED) may go on under
strong electrical interference. Additional measures are not
required. Turn the ignition switch off to stop the indicator
light.

If the yellow engine warning indicator light (LED) of the

motorcycle brought in for repair still goes on or blinks, check
the service code.

When the repair has been done, the yellow engine warn-

ing indicator light (LED) goes off. But the service codes
stored in memory of the ECU are not erased to preserve
the problem history. The problem history can be referred
using the KDS (Kawasaki Diagnostic System) when solv-
ing unstable problems.

When the motorcycle is down, the vehicle-down sensor

operates and the ECU shuts off the fuel pump relay, fuel
injectors and ignition system. The ignition switch is left on. If
the starter button is pushed, the electric starter turns but the
engine does not start. When the starter button is pushed,
the yellow engine warning indicator light (LED) blinks but
the service code is not displayed. To start the engine again,
raise the motorcycle, turn the ignition switch off, and then
on.

Much of the DFI system troubleshooting work consists

of confirming continuity of the wiring. The DFI parts are
assembled and adjusted with precision, and it is impossible
to disassemble or repair them.

○

The DFI part connectors [A] have seals [B], including the
ECU.

•

Join the connector and insert the needle adapters [C] in-
side the seals from behind the connector until the adapter
reaches the terminal.

Special Tool - Needle Adapter Set: 57001-1457

NOTICE

Insert the needle adapter straight along the terminal
in the connector to prevent short-circuit between
terminals.

•

Make sure that measuring points are correct in the con-
nector, noting the position of the lock [D] and the lead
color before measurement. Do not reverse connections
of the hand tester or a digital meter.

•

Be careful not to short-circuit the leads of the DFI or elec-
trical system parts by contact between adapters.

•

Turn the ignition switch on and measure the voltage with
the connector joined.

NOTICE

Incorrect, reverse connection or short circuit by
needle adapters could damage the DFI or electrical
system parts.

FUEL SYSTEM (DFI) 3-27

Troubleshooting the DFI System

○

After measurement, remove the needle adapters and ap-
ply silicone sealant to the seals [A] of the connector [B]
for waterproofing.

Sealant - Liquid Gasket, TB1211: 56019-120

•

Always check battery condition before replacing the DFI
parts. A fully charged battery is a must for conducting
accurate tests of the DFI system.

•

Trouble may involve one or in some cases all items.
Never replace a defective part without determining what
CAUSED the problem. If the problem was caused by
some other item or items, they too must be repaired or
replaced, or the new replacement part will soon fail again.

•

Measure the coil winding resistance when the DFI part is
cold (at room temperature).

•

Make sure all connectors in the circuit are clean and tight,
and examine leads for signs of burning, fraying, short,
etc. Deteriorated leads and bad connections can cause
reappearance of problems and unstable operation of the
DFI system.
If any wiring is deteriorated, replace the wiring.

•

Pull each connector [A] apart and inspect it for corrosion,
dirt, and damage.
If the connector is corroded or dirty, clean it carefully. If it
is damaged, replace it. Connect the connectors securely.

•

Check the wiring for continuity.

○

Use the wiring diagram to find the ends of the lead which
is suspected of being a problem.

○

Connect the hand tester between the ends of the leads.

Special Tool - Hand Tester: 57001-1394

○

Set the tester to the × 1

Ω

range, and read the tester.

If the tester does not read 0

Ω

, the lead is defective. Re-

place the lead or the main harness [B].

○

If both ends of a harness [A] are far apart, ground [B] the
one end [C], using a jumper lead [D] and check the con-
tinuity between the end [E] and the ground [F]. This en-
ables to check a long harness for continuity. If the harness
is open, repair or replace the harness.

FUEL SYSTEM (DFI) 3-29

Troubleshooting the DFI System

Inquiries to Rider

○

Each rider reacts to problems in different ways, so it is important to confirm what kind of symptoms
the rider has encountered.

○

Try to find out exactly what problem occurred under exactly what conditions by asking the rider;
knowing this information may help you reproduce the problem.

○

The following sample diagnosis sheet will help prevent you from overlooking any areas, and will
help you decide if it is a DFI system problem, or a general engine problem.

Sample Diagnosis Sheet

Rider name:

Registration No. (license plate No.):

Year of initial registration:

Model:

Engine No.:

Frame No.:

Date problem occurred:

Mileage:

Environment when problem occurred.

Weather

□

fine,

□

cloudy,

□

rain,

□

snow,

□

always,

□

other:

Temperature

□

hot,

□

warm,

□

cold,

□

very cold,

□

always,

□

other:

Problem
frequency

□

chronic,

□

often,

□

once

Road

□

street,

□

highway,

□

mountain road (

□

uphill,

□

downhill),

□

bumpy,

□

pebble

Altitude

□

normal,

□

high (about 1 000 m or more)

Motorcycle conditions when problem occurred.

□

goes on immediately after turning the ignition switch on, and goes off after about

2 seconds (normal)

□

goes on immediately after turning the ignition switch on, goes off after about 2

seconds, and goes on again after about 10 seconds (ECU communication error)

□

goes on immediately after turning the ignition switch on, goes off after about

2 seconds, and goes on again (DFI problem)

□

goes on immediately after turning the ignition switch on, and stays on (DFI

problem)

Yellow engine
warning
indicator light
(LED)

□

does not go on after turning the ignition switch on (light (LED), ECU or its wiring

fault)

□

starter motor not rotating

□

starter motor rotating but engine doesn’t turn over

□

starter motor and engine don’t turn over

□

no fuel flow (

□

no fuel in tank,

□

no fuel pump sound)

□

no spark

Starting
difficulty

□

other

□

right after starting

□

when opening throttle grip

□

when closing throttle grip

□

when moving off

□

when stopping the motorcycle

□

when cruising

Engine stops

□

other

3-30 FUEL SYSTEM (DFI)

Troubleshooting the DFI System

□

very low idle speed,

□

very high idle speed,

□

rough idle speed

□

battery voltage is low (charge the battery)

□

spark plug loose (tighten it)

□

spark plug dirty, broken, or gap maladjusted (remedy it)

□

backfiring

□

afterfiring

□

hesitation when acceleration

□

engine oil viscosity too high

□

brake dragging

□

engine overheating

Poor running
at low speed

□

clutch slipping

□

other

□

spark plug loose (tighten it)

□

spark plug dirty, broken, or gap maladjusted (remedy it)

□

spark plug incorrect (replace it)

□

knocking (fuel poor quality or incorrect,

→

use unleaded gasoline)

□

brake dragging

□

clutch slipping

□

engine overheating

□

engine oil level too high

□

engine oil viscosity too high

Poor running
or no power at
high speed

□

other

FUEL SYSTEM (DFI) 3-31

DFI System Troubleshooting Guide

NOTE

○

This is not an exhaustive list, giving every possible cause for each problem listed. It is meant
simply as a rough guide to assist the troubleshooting for some of the more common difficulties in
DFI system.

○

The ECU may be involved in the DFI electrical and ignition system troubles. If these parts and
circuits are checked out good, be sure to check the ECU for ground and power supply. If the
ground and power supply are checked good, replace the ECU.

Engine Won’t Turn Over

Symptoms or Possible Causes

Actions

Neutral, starter lockout or sidestand switch
trouble

Inspect each switch (see chapter 16).

Vehicle-down sensor operated

Turn the ignition switch off (see chapter 3).

Vehicle-down sensor trouble

Inspect (see chapter 3).

Crankshaft sensor trouble

Inspect (see chapter 16).

Stick coil shorted or not in good contact

Inspect or Reinstall (see chapter 16).

Stick coil trouble

Inspect (see chapter 16).

Spark plug dirty, broken or gap maladjusted

Inspect and replace (see chapter 2).

Spark plug incorrect

Replace it with the correct plug (see chapter 2).

ECU ground and power supply trouble

Inspect (see chapter 3).

ECU trouble

Inspect (see chapter 3).

No or little fuel in tank

Supply fuel (see Owner’s Manual).

Fuel injector trouble

Inspect and replace (see chapter 3).

Fuel pump not operating

Inspect (see chapter 3).

Fuel pump relay trouble

Inspect and replace (see chapter 3).

Fuel filter or pump screen clogged

Inspect and replace fuel pump (see chapter 3).

Fuel pressure regulator trouble

Inspect fuel pressure and replace fuel pump (see
chapter 3).

Fuel line clogged

Inspect and repair (see chapter 3).

Poor Running at Low Speed

Symptoms or Possible Causes

Actions

Spark weak:

Stick coil shorted or not in good contact

Inspect or Reinstall (see chapter 16).

Stick coil trouble

Inspect (see chapter 16).

Spark plug dirty, broken or gap maladjusted

Inspect and replace (see chapter 2).

Spark plug incorrect

Replace it with the correct plug (see chapter 2).

ECU trouble

Inspect (see chapter 3).

Fuel/air mixture incorrect:

Little fuel in tank

Supply fuel (see Owner’s Manual).

Air cleaner clogged, poorly sealed, or missing

Clean element or inspect sealing (see chapter 2).

Air duct loose

Reinstall (see chapter 3).

Throttle body assy holder loose

Reinstall (see chapter 3).

Throttle body assy dust seal damage

Replace (see chapter 3).

Fuel injector O-ring damage

Replace (see chapter 3).

Fuel filter or pump screen clogged

Inspect and replace fuel pump (see chapter 3).

3-32 FUEL SYSTEM (DFI)

DFI System Troubleshooting Guide

Symptoms or Possible Causes

Actions

Fuel pressure regulator trouble

Inspect fuel pressure and replace fuel pump (see
chapter 3).

Fuel line clogged

Inspect and repair (see chapter 3).

Intake air pressure sensor trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Main throttle sensor trouble

Inspect (see chapter 3).

Subthrottle sensor trouble

Inspect (see chapter 3).

Subthrottle valve actuator trouble

Inspect (see chapter 3).

Unstable (rough) idling:

Fuel pressure too low or too high

Inspect (see chapter 3).

Fuel injector trouble

Inspect (see chapter 3).

Main throttle sensor trouble

Inspect (see chapter 3).

Subthrottle sensor trouble

Inspect (see chapter 3).

Subthrottle valve actuator trouble

Inspect (see chapter 3).

Engine vacuum not synchronizing

Inspect and adjust (see chapter 2).

Intake air pressure sensor trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Engine stalls easily:

Spark plug dirty, broken or gap maladjusted

Inspect and replace (see chapter 2).

Stick coil trouble

Inspect (see chapter 16).

Main throttle sensor trouble

Inspect (see chapter 3).

Subthrottle sensor trouble

Inspect (see chapter 3).

Subthrottle valve actuator trouble

Inspect (see chapter 3).

Intake air pressure sensor trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Fuel pump trouble

Inspect (see chapter 3).

Fuel injector trouble

Inspect (see chapter 3).

Fuel pressure too low or too high

Inspect (see chapter 3).

Fuel pressure regulator trouble

Inspect fuel pressure and replace fuel pump (see
chapter 3).

Fuel line clogged

Inspect and repair (see chapter 3).

Poor acceleration:

Fuel pressure too low

Inspect (see chapter 3).

Water or foreign matter in fuel

Change fuel. Inspect and clean fuel system (see
chapter 3).

Fuel filter or pump screen clogged

Inspect and replace fuel pump (see chapter 3).

Fuel pump trouble

Inspect (see chapter 3).

Fuel injector trouble

Inspect (see chapter 3).

Main throttle sensor trouble

Inspect (see chapter 3).

Subthrottle sensor trouble

Inspect (see chapter 3).

Subthrottle valve actuator trouble

Inspect (see chapter 3).

Intake air pressure sensor trouble

Inspect (see chapter 3).

FUEL SYSTEM (DFI) 3-33

DFI System Troubleshooting Guide

Symptoms or Possible Causes

Actions

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Spark plug dirty, broken or gap maladjusted

Inspect and replace (see chapter 2).

Stick coil trouble

Inspect (see chapter 16).

Stumble:

Fuel pressure too low

Inspect (see chapter 3).

Fuel injector trouble

Inspect (see chapter 3).

Main throttle sensor trouble

Inspect (see chapter 3).

Subthrottle sensor trouble

Inspect (see chapter 3).

Subthrottle valve actuator trouble

Inspect (see chapter 3).

Intake air pressure sensor trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Surge:

Unstable fuel pressure

Fuel pressure regulator trouble (Inspect and
replace fuel pump) or kinked fuel line (Inspect
and replace fuel pump) (see chapter 3).

Fuel injector trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Backfiring when deceleration:

Spark plug dirty, broken or gap maladjusted

Inspect and replace (see chapter 2).

Fuel pressure too low

Inspect (see chapter 3).

Fuel pump trouble

Inspect (see chapter 3).

Main throttle sensor trouble

Inspect (see chapter 3).

Subthrottle sensor trouble

Inspect (see chapter 3).

Subthrottle valve actuator trouble

Inspect (see chapter 3).

Intake air pressure sensor trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Air switching valve trouble

Inspect and replace (see chapter 16).

Air suction valve trouble

Inspect and replace (see chapter 5).

After fire:

Spark plug burned or gap maladjusted

Replace (see chapter 2).

Fuel injector trouble

Inspect (see chapter 3).

Intake air pressure sensor trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Other:

Intermittent any DFI fault and its recovery

Check that DFI connectors are clean and tight,
and examine leads for signs of burning or fraying
(see chapter 3).

3-34 FUEL SYSTEM (DFI)

DFI System Troubleshooting Guide

Poor Running or No Power at High Speed

Symptoms or Possible Causes

Actions

Firing incorrect:

Stick coil shorted or not in good contact

Inspect or Reinstall (see chapter 16).

Stick coil trouble

Inspect (see chapter 16).

Spark plug dirty, broken or gap maladjusted

Inspect and replace (see chapter 2).

Spark plug incorrect

Replace it with the correct plug (see chapter 2).

ECU trouble

Inspect (see chapter 3).

Fuel/air mixture incorrect:

Air cleaner clogged, poorly sealed, or missing

Clean element or inspect sealing (see chapter 2).

Air duct loose

Reinstall (see chapter 3).

Throttle body assy holder loose

Reinstall (see chapter 3).

Throttle body assy dust seal damage

Replace (see chapter 3).

Water or foreign matter in fuel

Change fuel. Inspect and clean fuel system (see
chapter 3).

Fuel injector O-ring damage

Replace (see chapter 3).

Fuel injector clogged

Inspect and repair (see chapter 3).

Fuel line clogged

Inspect and repair (see chapter 3).

Fuel pump operates intermittently and often FI
fuse blows.

Fuel pump bearings may wear. Replace the fuel
pump (see chapter 3).

Fuel pump trouble

Inspect (see chapter 3).

Intake air pressure sensor trouble

Inspect (see chapter 3).

Cracked or obstructed intake air pressure sensor
vacuum hose

Inspect and repair or replace (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Main throttle sensor trouble

Inspect (see chapter 3).

Subthrottle sensor trouble

Inspect (see chapter 3).

Subthrottle valve actuator trouble

Inspect (see chapter 3).

Knocking:

Fuel poor quality or incorrect

Fuel change (Use the gasoline recommended in
the Owner’s Manual).

Spark plug incorrect

Replace it with the correct plug (see chapter 2).

Stick coil trouble

Inspect (see chapter 16).

ECU trouble

Inspect (see chapter 3).

Engine vacuum not synchronizing

Inspect and adjust (see chapter 2).

Intake air pressure sensor trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

Miscellaneous:

Subthrottle sensor trouble

Inspect (see chapter 3).

Subthrottle valve actuator trouble

Inspect (see chapter 3).

Speed sensor trouble

Inspect (see chapter 3).

Throttle valves will not fully open

Inspect throttle cables and lever linkage (see
chapter 3).

FUEL SYSTEM (DFI) 3-35

DFI System Troubleshooting Guide

Symptoms or Possible Causes

Actions

Engine overheating - Water temperature sensor,
crankshaft sensor or speed sensor trouble

(see Overheating of Troubleshooting Guide in
chapter 17)

Air switching valve trouble

Inspect and replace (see chapter 16).

Air suction valve trouble

Inspect and replace (see chapter 5).

Exhaust Smokes Excessively:
(Black smoke)

Air cleaner element clogged

Clean element (see chapter 2).

Fuel pressure too high

Inspect (see chapter 3).

Fuel injector trouble

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

(Brown smoke)

Air duct loose

Reinstall (see chapter 3).

Fuel pressure too low

Inspect (see chapter 3).

Water temperature sensor trouble

Inspect (see chapter 3).

Intake air temperature sensor trouble

Inspect (see chapter 3).

3-36 FUEL SYSTEM (DFI)

Self-Diagnosis

Self-diagnosis Outline

The self-diagnosis system has 2 modes and can be

switched to another mode by operating the meter unit.

User Mode

The ECU notifies the rider of troubles in DFI system and

ignition system by lighting the yellow engine warning indi-
cator light (LED) [A] when DFI and ignition system parts
are faulty, and initiates fail-safe function. In case of serious
troubles ECU stops the injection and ignition operations.

Dealer Mode

The LCD (Liquid Crystal Display) displays the service

code(s) [A] to show the problem(s) which the DFI system
and ignition system has at the moment of diagnosis.

Self-diagnosis Procedures

○

When a problem occurs with the DFI system and ignition
system, the yellow engine warning indicator light (LED)
[A] goes on.

NOTE

○

Use a fully charged battery when conducting
self-diagnosis. Otherwise, the light (LED) does not
go on.

•

Turn the ignition switch on.

•

Press the left button [A] to select the odometer [B].

FUEL SYSTEM (DFI) 3-39

Self-Diagnosis

Service Code Reading

○

The service code(s) [A] is displayed on the LCD by the number of two digits.

○

When there are a number of problems, all the service codes can be stored and the display will begin
starting from the lowest number service code in the numerical order.

○

Then after completing all codes, the display is repeated until the ignition switch is turned off or the
left button is pressed for more than 2 seconds.

○

For example, if three problems occurred in the order of 51, 13, 32, the service codes are displayed
(each two seconds) from the lowest number in the order listed as shown below. (13

→

51)

→

(13

→

51)

→

· · ·(repeated)

○

If there is no problem or when the repair has been done, the yellow engine warning indicator light
(LED) goes off and service code is not displayed.

Service Code Erasing

○

When repair has been done, the yellow engine warning indicator light (LED) goes off and service
code is not displayed.
The service codes stored in memory of the ECU can be erased using Kawasaki Diagnostic System
(KDS Ver.3).

3-40 FUEL SYSTEM (DFI)

Self-Diagnosis

Service Code Table

Service Code

Problems

Main throttle sensor malfunction, wiring open or short

Intake air pressure sensor malfunction, wiring open or short

Intake air temperature sensor malfunction, wiring open or short

Water temperature sensor malfunction, wiring open or short

Crankshaft sensor malfunction, wiring open or short

Speed sensor malfunction, wiring open or short

Vehicle-down sensor malfunction, wiring open or short

Subthrottle sensor malfunction, wiring open or short

Oxygen sensor inactivation, wiring open or short (equipped models)

Stick coil #1 malfunction, wiring open or short

Stick coil #2 malfunction, wiring open or short

Radiator fan relay malfunction, wiring open or short

Subthrottle valve actuator malfunction, wiring open or short

Air switching valve malfunction, wiring open or short

Oxygen sensor heater malfunction, wiring open or short (equipped models)

Oxygen sensor malfunction, wiring open or short (equipped models)

Purge valve malfunction, wiring open or short (CAL model)

Notes:

○

The ECU may be involved in these problems. If all the parts and circuits checked out good, be sure
to check the ECU for ground and power supply. If the ground and power supply are checked good,
replace the ECU.

○

When no service code is displayed, the electrical parts of the DFI system has no fault, and the
mechanical parts of the DFI system and the engine are suspect.

FUEL SYSTEM (DFI) 3-41

Self-Diagnosis

Backups

○

The ECU takes the following measures to prevent engine damage when the DFI or the ignition
system parts have troubles.

Service

Codes

Parts

Output Signal Usable

Range or Criteria

Backups by ECU

Main Throttle

Sensor

Main Throttle Sensor
Output Voltage
0.2

∼

4.8 V

If the main throttle sensor system fails (the
output voltage is out of the usable range,
wiring short or open), the ECU locks ignition
timing into the ignition timing at closed throttle
position and sets the DFI in the D-J method
(1).
Also, the main throttle sensor system and
intake air pressure fails, the ECU locks ignition
timing into the ignition timing at closed throttle
position and sets the DFI in the

-N method

(2).

Intake Air

Pressure

Sensor

Intake Air Pressure
(absolute)
Pv = 150

∼

800 mmHg

If the intake air pressure sensor system fails
(the signal is out of the usable range, wiring
short or open), the ECU sets the DFI in the

-N method.

Intake Air

Temperature

Sensor

Intake Air Temperature
Ta = –30°C

∼

+120°C

If the intake air temperature sensor fails (the
signal is out of the usable range, wiring short
or open), the ECU sets Ta at 40°C.

Water

Temperature

Sensor

Water Temperature
Tw = –30°C

∼

+120°C

If the water temperature sensor system fails
(the signal is out of the usable range, wiring
short or open), the ECU sets Tw at 80°C.

Crankshaft

Sensor

Crankshaft sensor must
send 22 signals to
the ECU at the one
cranking.

If the crankshaft sensor generates other than
22 signals, the engine stops by itself.

Speed Sensor

Speed sensor must
send 4 signals to the
ECU at the one rotation
of the engine sprocket.
The gear position is
decided by the signal of
the speed sensor.

If the speed sensor system fails (no signal,
wiring short or open), the speedometer shows
0, and the ECU sets the top (6) gear position.

Vehicle-down

Sensor

Output Voltage (signal)
Vd = 0.65

∼

4.45 V

If the vehicle-down sensor system has failures
(the output voltage Vd is more than usable
range, wiring open), the ECU shuts off the
fuel pump, the fuel injectors and the ignition
system.

Subthrottle

Sensor

Output Voltage
0.15

∼

4.85 V

If the subthrottle sensor system fails (the
signal is out of the usable range, wiring short
or open), the ECU drive the subthrottle valve
to the full closed position, and it stops the
current to the actuator.

Oxygen Sensor

(Equipped

Models)

The oxygen sensor is
active and sensor must
send signals (output
voltage) continuously to
the ECU.

If the oxygen sensor is not activated, the ECU
stops oxygen sensor feedback mode.

3-42 FUEL SYSTEM (DFI)

Self-Diagnosis

Service

Codes

Parts

Output Signal Usable

Range or Criteria

Backups by ECU

Stick Coil #1*

The ECU must send
signals continuously to
the stick coil primary
winding.

If the stick coil #1 primary winding has failures
(no signal, wiring short or open), the ECU
shuts off the injector #1 to stop fuel to the
cylinder #1, though the engine keeps running.

Stick Coil #2*

The ECU must send
signals continuously to
the stick coil primary
winding.

If the stick coil #2 primary winding has failures
(no signal, wiring short or open), the ECU
shuts off the injector #2 to stop fuel to the
cylinder #2, though the engine keeps running.

Radiator Fan

Relay

When the relay OFF
condition, the fan relay
is open.

–

Subthrottle

Valve Actuator

The actuator operates
open and close of the
subthrottle valve by the
pulse signal from the
ECU.

If the subthrottle valve actuator fails (the
signal is out of the usable range, wiring short
or open), the ECU stops the current to the
actuator.

Air Switching

Valve

The air switching valve
controls the flow of
the secondary air by
opening and shutting
the solenoid valve.

–

Oxygen Sensor

(Equipped

Models)

The oxygen sensor
heater raise
temperature of the
sensor for its earlier
activation. 12 V-6.6 W,
0.55 A

If the oxygen sensor heater fails (wiring short
or open), the ECU stops the current to the
heater.

Oxygen Sensor

(Equipped

Models)

The oxygen sensor
must send signals
(output voltage)
continuously to the
ECU.

If the oxygen sensor output voltage is incorrect,
the ECU stops oxygen sensor feed back mode.

Purge Valve

(CAL Model)

The purge valve
controls the flow of
the secondary air by
opening and shutting
the solenoid valve.

–

Note:

(1): D-J Method: When the engine load is light like at idling or low speed, the ECU determines

the injection quantity by calculating from the throttle vacuum (intake air pressure sensor output
voltage) and engine speed (crankshaft sensor output voltage). This method is called D-J method
(low-speed mode).

(2):

-N Method: As the engine speed increases, and the engine load turns middle to heavy, the

ECU determines the injection quantity by calculating from the throttle opening (throttle sensor
output voltage) and the engine speed. This method is called

-N method (high-speed mode).

(*): This depends on the number of stopped cylinders.

FUEL SYSTEM (DFI) 3-43

Main Throttle Sensor (Service Code 11)

Main Throttle Sensor Removal/Adjustment

NOTICE

Do not remove or adjust the main throttle sensor [A]
since it has been adjusted and set with precision at
the factory.
Never drop the throttle body assy especially on a
hard surface. Such a shock to the main throttle sen-
sor can damage it.

Main Throttle Sensor Input Voltage Inspection

NOTE

○

Be sure the battery is fully charged.

•

Turn the ignition switch off.

•

Remove the right middle fairing (see Middle Fairing Re-
moval in the Frame chapter).

•

Disconnect the main throttle sensor connector and con-
nect the harness adapter [A] between these connectors.

Special Tool - Throttle Sensor Setting Adapter:

57001

-1538

•

Connect a digital meter to the harness adapter leads.

Main Throttle Sensor Input Voltage

Connections to Adapter:

Digital Meter (+)

→

BK (sensor G) lead

Digital Meter (–)

→

W (sensor BR/BK) lead

•

Measure the input voltage with the engine stopped and
with the connector joined.

•

Turn the ignition switch on.

Input Voltage

Standard: DC 4.75

∼

5.25 V

•

Turn the ignition switch off.
If the reading is within the standard, check the output volt-
age (see Main Throttle Sensor Output Voltage Inspec-
tion).

If the reading is out of the standard, remove the ECU
and check the wiring for continuity between main harness
connectors.

Special Tool - Hand Tester: 57001-1394

○

Disconnect the ECU and sensor connectors.

Wiring Continuity Inspection

ECU Connector [A]

←→

Main Throttle Sensor Connector [B]

G lead (ECU terminal 8) [C]
BR/BK lead (ECU terminal 22) [D]

If the wiring is good, check the ECU for its ground and
power supply (see ECU Power Supply Inspection).
If the ground and power supply are good, replace the ECU
(see ECU Removal/Installation).

3-44 FUEL SYSTEM (DFI)

Main Throttle Sensor (Service Code 11)

Main Throttle Sensor Output Voltage Inspection

•

Measure the output voltage at the main throttle sensor in
the same way as input voltage inspection.

○

Disconnect the main throttle sensor connector and con-
nect the harness adapter [A] between these connectors.

Special Tool - Throttle Sensor Setting Adapter:

57001

-1538

Main Throttle Sensor Output Voltage

Connections to Adapter:

Digital Meter (+)

→

R (sensor Y/W) lead

Digital Meter (–)

→

W (sensor BR/BK) lead

•

Start the engine and warm it up thoroughly.

•

Check idle speed to ensure the throttle opening is correct.

Idle Speed

Standard: 1 300 ±50 r/min (rpm)

If the idle speed is out of the specified range, adjust it
(see Idle Speed Adjustment in the Periodic Maintenance
chapter).

•

Turn the ignition switch off.

•

Measure the output voltage with the engine stopped and
with the connector joined.

•

Turn the ignition switch on.

Output Voltage

Standard: DC 1.020

∼

1.050 V at idle throttle opening

DC 4.212

∼

4.322 V at full throttle opening

(for reference)

NOTE

○

Open the throttle, confirm the output voltage will be
raise.

○

The standard voltage refers to the value when the volt-
age reading at the Input Voltage Inspection shows 5 V
exactly.

○

When the input voltage reading shows other than 5 V,
derive a voltage range as follows.
Example:
In the case of a input voltage of 4.75 V.
1.020 × 4.75 ÷ 5.00 = 0.969 V
1.050 × 4.75 ÷ 5.00 = 0.998 V
Thus, the valid range is 0.969

∼

0.998 V

•

Turn the ignition switch off.
If the reading is out of the standard, check the main throt-
tle sensor resistance (see Main Throttle Sensor Resis-
tance Inspection).

FUEL SYSTEM (DFI) 3-45

Main Throttle Sensor (Service Code 11)

If the reading is within the standard, remove the ECU and
check the wiring for continuity between main harness con-
nectors.

Special Tool - Hand Tester: 57001-1394

○

Disconnect the ECU and sensor connectors.

Wiring Continuity Inspection

ECU Connector [A]

←→

Main Throttle Sensor Connector [B]

Y/W lead (ECU terminal 6) [C]
BR/BK lead (ECU terminal 22) [D]

If the wiring is good, check the ECU for its ground and
power supply (see ECU Power Supply Inspection).
If the ground and power supply are good, replace the ECU
(see ECU Removal/Installation).

Main Throttle Sensor Resistance Inspection

•

Turn the ignition switch off.

•

Disconnect the main throttle sensor connector.

•

Connect a digital meter [A] to the main throttle sensor
connector [B].

•

Measure the main throttle sensor resistance.

Main Throttle Sensor Resistance

Connections:

G lead [C]

←→

BR/BK lead [D]

Standard:

∼

6 k

Ω

If the reading is out of the standard, replace the throttle
body assy (see Throttle Body Assy Removal/Installation).
If the reading is within the standard, but the problem still
exists, replace the ECU (see ECU Removal/Installation).

Main Throttle Sensor Circuit

1. ECU
2. Main Throttle Sensor
3. Water-proof Joint 4
4. Water-proof Joint 3

3-46 FUEL SYSTEM (DFI)

Intake Air Pressure Sensor (Service Code 12)

Intake Air Pressure Sensor Removal

NOTICE

Never drop the intake air pressure sensor espe-
cially on a hard surface. Such a shock to the sensor
can damage it.

•

Remove the fuel tank (see Fuel Tank Removal).

•

Disconnect the intake air pressure sensor connector [A].

•

Remove the intake air pressure sensor [A] from the rubber
damper [B] of the air switching valve and disconnect the
vacuum hose [C].

Intake Air Pressure Sensor Installation

•

Installation is the reverse of removal.

Intake Air Pressure Sensor Input Voltage

Inspection

NOTE

○

Be sure the battery is fully charged.

•

Turn the ignition switch off.

•

Remove the fuel tank (see Fuel Tank Removal).

•

Disconnect the intake air pressure sensor connector and
connect the harness adapter [A] between these connec-
tors.

Special Tool - Measuring Adapter: 57001-1700

•

Connect a digital meter to the harness adapter leads.

Intake Air Pressure Sensor Input Voltage

Connections to Adapter:

Digital Meter (+)

→

G (sensor G) lead

Digital Meter (–)

→

G/W (sensor BR/BK) lead

•

Measure the input voltage with the engine stopped and
with the connector joined.

•

Turn the ignition switch on.

Input Voltage

Standard: DC 4.75

∼

5.25 V

•

Turn the ignition switch off.
If the reading is within the standard, check the output volt-
age (see Intake Air Pressure Sensor Output Voltage In-
spection).

FUEL SYSTEM (DFI) 3-47

Intake Air Pressure Sensor (Service Code 12)

If the reading is out of the standard, remove the ECU
and check the wiring for continuity between main harness
connectors.

Special Tool - Hand Tester: 57001-1394

○

Disconnect the ECU and sensor connectors.

Wiring Continuity Inspection

ECU Connector [A]

←→

Intake Air Pressure Sensor Connector [B]

G lead (ECU terminal 8) [C]
BR/BK lead (ECU terminal 22) [D]

If the wiring is good, check the ECU for its ground and
power supply (see ECU Power Supply Inspection).
If the ground and power supply are good, replace the ECU
(see ECU Removal/Installation).

Intake Air Pressure Sensor Output Voltage

Inspection

•

Measure the output voltage at the intake air pressure sen-
sor in the same way as input voltage inspection.

○

Disconnect the intake air pressure sensor connector and
connect the harness adapter [A] between these connec-
tors.

Special Tool - Measuring Adapter: 57001-1700

Intake Air Pressure Sensor Output Voltage

Connections to Adapter:

Digital Meter (+)

→

BK (sensor Y/BL) lead

Digital Meter (–)

→

G/W (sensor BR/BK) lead

•

Measure the output voltage with the engine stopped and
with the connector joined.

•

Turn the ignition switch on.

Output Voltage

Usable Range:

DC 3.80

∼

4.20 V at standard

atmospheric pressure (101.32 kPa,
76 cmHg)

NOTE

○

The output voltage changes according to local atmo-
spheric pressure.

•

Turn the ignition switch off.
If the reading is out of the usable range, replace the sen-
sor.

If the reading is within the usable range, remove the ECU
and check the wiring for continuity between main harness
connector.

Special Tool - Hand Tester: 57001-1394

○

Disconnect the ECU and sensor connectors.

Wiring Continuity Inspection

ECU Connector [A]

←→

Intake Air Pressure Sensor Connector [B]

Y/BL lead (ECU terminal 7) [C]
BR/BK lead (ECU terminal 22) [D]

3-48 FUEL SYSTEM (DFI)

Intake Air Pressure Sensor (Service Code 12)

If the wiring is good, check the sensor for various vacuum.

•

Remove the intake air pressure sensor [A] and disconnect
the vacuum hose from the sensor.

•

Connect an auxiliary hose [B] to the intake air pressure
sensor.

•

Temporarily install the intake air pressure sensor.

○

Connect a digital meter [C], vacuum gauge [D], the fork
oil level gauge [E] and the harness adapter to the intake
air pressure sensor.

Special Tools - Fork Oil Level Gauge: 57001-1290

Vacuum Gauge: 57001-1369
Measuring Adapter: 57001-1700

Intake Air Pressure Sensor Output Voltage

Connections to Adapter:

Digital Meter (+)

→

BK (sensor Y/BL) lead

Digital Meter (–)

→

G/W (sensor BR/BK) lead

○

Turn the ignition switch on.

○

Measure the intake air pressure sensor output voltage
from various vacuum readings, while pulling the handle
of the fork oil level gauge.

○

Check the intake air pressure sensor output voltage, us-
ing the following formula and chart.

Suppose:

Pg: Vacuum Pressure (Gauge) to Sensor

Pl: Local Atmospheric Pressure (Absolute) measured by a barometer

Pv: Vacuum Pressure (Absolute) to Sensor
Vv: Sensor Output Voltage (V)

then

Pv = Pl – Pg

For example, suppose the following data is obtained:

Pg = 8 cmHg (Vacuum Gauge Reading)

Pl = 70 cmHg (Varometer Reading)

Vv = 3.2 V (Digital Meter Reading)

then

Pv = 70 – 8 = 62 cmHg (Absolute)

Plot this Pv (62 cmHg) at a point [1] on the chart and draw a vertical line through the point. Then, you
can get the usable range [2] of the sensor output voltage.

Usable range = 3.04

∼

3.49 V

Plot Vv (3.2 V) on the vertical line.

→

Point [3].

Results: In the chart, Vv is within the usable range and the sensor is normal.

Kawasaki Ninja 300 / Ninja 300 ABS Motorcycle. Service Manual (2013) - page 4