DFI Diagnosis Flow Chart

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.

FUEL SYSTEM (DFI) 3-33
Troubleshooting the DFI System
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
□ chronic, □ often, □once
frequency
Road
□ street, □ highway, □ mountain road (□ uphill, □ downhill), □ bumpy, □ pebble
Altitude
□ normal, □ high (about 1 000 m or more)
Motorcycle conditions when problem occurred.
Yellow engine □ goes on immediately after turning the ignition switch on, and goes off after
warning
starting the engine (normal)
indicator light □ goes on immediately after turning the ignition switch on, goes off after about 1
(LED)
second, and goes on again after about 10 seconds (ECU communication error)
□ goes on immediately after turning the ignition switch on, and stays on after
starting the engine (DFI problem)
□ does not go on after turning the ignition switch on (indicator light (LED), meter
unit fault)
Red warning □ Does not go on about 1 second after ignition switch on (ECU or meter unit fault).
indicator light
□ light up (battery, oil pressure, water temperature or meter unit problem)
(LED)
Starting
□ starter motor not rotating.
difficulty
□ starter motor rotating but engine do not turn over.
□ starter motor and engine do not turn over.
□ no fuel flow (□ no fuel in tank, □ no fuel pump sound).
□ no spark.
□ other:
Engine stalls □ right after starting.
□ when opening throttle grip.
□ when closing throttle grip.
□ when moving off.
□ when stopping the motorcycle.
□ when cruising.
□ other:

3-34 FUEL SYSTEM (DFI)
Troubleshooting the DFI System
Poor running
at low speed

Poor running
or no power at
high speed

□ 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 or broken.
□ backfiring.
□ afterfiring.
□ hesitation when acceleration.
□ engine oil viscosity too high.
□ brake dragging.
□ engine overheating.
□ clutch slipping.
□ other:
□ spark plug loose (tighten it).
□ spark plug dirty or broken.
□ spark plug incorrect (replace it).
□ knocking (fuel poor quality or incorrect).
□ brake dragging.
□ clutch slipping.
□ engine overheating.
□ engine oil level too high.
□ engine oil viscosity too high.
□ other:

FUEL SYSTEM (DFI) 3-35
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
Gear position sensor, starter lockout or side
stand switch trouble
Vehicle-down sensor operated
Vehicle-down sensor trouble
Crankshaft sensor trouble
Stick coil shorted or not in good contact
Stick coil trouble
Spark plug dirty, broken or gap maladjusted
Spark plug incorrect
ECU ground and power supply trouble
ECU trouble
No or little fuel in tank
Fuel injector trouble
Fuel pump not operating
Fuel pump relay trouble
Fuel filter clogged
Fuel pressure regulator trouble
Fuel line clogged

Actions (chapter)
Inspect each sensor or switch (see chapter 3 or
16).
Turn ignition switch off (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 16).
Inspect or reinstall (see chapter 16).
Inspect (see chapter 16).
Inspect and replace (see chapter 16).
Replace it with the correct plug (see chapter 2).
Inspect (see chapter 3).
Inspect (see chapter 3).
Supply fuel (see Owner’s Manual).
Inspect and replace (see chapter 3).
Inspect (see chapter 3).
Inspect and replace (see chapter 16).
Replace fuel filter (see chapter 2).
Inspect fuel pressure and replace fuel pump (see
chapter 3).
Inspect and repair (see chapter 3).

Poor Running at Low Speed
Symptoms or Possible Causes
Spark weak:
Stick coil shorted or not in good contact
Stick coil trouble
Spark plug dirty, broken or gap maladjusted
Spark plug incorrect
ECU trouble
Fuel/air mixture incorrect:
Little fuel in tank
Air cleaner clogged, poorly sealed, or missing
Air duct loose
Throttle body assy holder loose
Throttle body assy dust seal damage
Fuel injector O-ring damage
Fuel filter clogged

Actions (chapter)
Inspect or reinstall (see chapter 16).
Inspect (see chapter 16).
Inspect and replace (see chapter 16).
Replace it with the correct plug (see chapter 2).
Inspect (see chapter 3).
Supply fuel (see Owner’s Manual).
Clean element or inspect sealing (see chapter 2).
Reinstall (see chapter 3).
Reinstall (see chapter 3).
Replace (see chapter 3).
Replace (see chapter 3).
Replace fuel filter (see chapter 2).

3-36 FUEL SYSTEM (DFI)
DFI System Troubleshooting Guide
Symptoms or Possible Causes
Fuel pressure regulator trouble
Fuel line clogged
Intake air pressure sensor trouble
Water temperature sensor trouble
Intake air temperature sensor trouble
Main throttle sensor trouble
Subthrottle sensor trouble
Subthrottle valve actuator trouble
Unstable (rough) idling:
Fuel pressure too low or too high
Fuel injector trouble
Main throttle sensor trouble
Subthrottle sensor trouble
Subthrottle valve actuator trouble
Engine vacuum not synchronizing
Intake air pressure sensor trouble
Water temperature sensor trouble
Intake air temperature sensor trouble
Engine stalls easily:
Spark plug dirty, broken or gap maladjusted
Stick coil trouble
Main throttle sensor trouble
Subthrottle sensor trouble
Subthrottle valve actuator trouble
Intake air pressure sensor trouble
Water temperature sensor trouble
Intake air temperature sensor trouble
Fuel pump trouble
Fuel injector trouble
Fuel pressure too low or too high
Fuel pressure regulator trouble
Fuel line clogged
Poor acceleration:
Fuel pressure too low
Water or foreign matter in fuel
Fuel filter clogged
Fuel pump trouble
Fuel injector trouble
Main throttle sensor trouble
Subthrottle sensor trouble
Subthrottle valve actuator trouble
Intake air pressure sensor trouble

Actions (chapter)
Inspect fuel pressure and replace fuel pump (see
chapter 3).
Inspect and repair (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect and adjust (see chapter 2).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect and replace (see chapter 16).
Inspect (see chapter 16).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect fuel pressure and replace fuel pump (see
chapter 3).
Inspect and repair (see chapter 3).
Inspect (see chapter 3).
Change fuel. Inspect and clean fuel system (see
chapter 3).
Replace fuel filter (see chapter 2).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).

FUEL SYSTEM (DFI) 3-37
DFI System Troubleshooting Guide
Symptoms or Possible Causes
Water temperature sensor trouble
Intake air temperature sensor trouble
Spark plug dirty, broken or gap maladjusted
Stick coil trouble
Stumble:
Fuel pressure too low
Fuel injector trouble
Main throttle sensor trouble
Subthrottle sensor trouble
Subthrottle valve actuator trouble
Intake air pressure sensor trouble
Water temperature sensor trouble
Intake air temperature sensor trouble
Surge:
Unstable fuel pressure

Fuel injector trouble
Water temperature sensor trouble
Backfiring when deceleration:
Spark plug dirty, broken or gap maladjusted
Fuel pressure too low
Fuel pump trouble
Main throttle sensor trouble
Subthrottle sensor trouble
Subthrottle valve actuator trouble
Intake air pressure sensor trouble
Water temperature sensor trouble
Intake air temperature sensor trouble
Air switching valve trouble
Air suction valve trouble
After fire:
Spark plug burned or gap maladjusted
Fuel injector trouble
Intake air pressure sensor trouble
Water temperature sensor trouble
Intake air temperature sensor trouble
Other:
Intermittent any DFI fault and its recovery

Actions (chapter)
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect and replace (see chapter 16).
Inspect (see chapter 16).
Inspect
Inspect
Inspect
Inspect
Inspect
Inspect
Inspect
Inspect

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Fuel pressure regulator trouble (Inspect and
replace fuel pump) or kinked fuel line (Inspect
and replace fuel line) (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect and replace (see chapter 16).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect and replace (see chapter 16).
Inspect and replace (see chapter 5).
Replace (see chapter 2).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Check that DFI connectors are clean and tight,
and examine leads for signs of burning or fraying
(see chapter 3).

3-38 FUEL SYSTEM (DFI)
DFI System Troubleshooting Guide
Poor Running or No Power at High Speed
Symptoms or Possible Causes
Firing incorrect:
Stick coil shorted or not in good contact
Stick coil trouble
Spark plug dirty, broken or gap maladjusted
Spark plug incorrect
ECU trouble
Fuel/air mixture incorrect:
Air cleaner clogged, poorly sealed, or missing
Air duct loose
Throttle body assy holder loose
Throttle body assy dust seal damage
Water or foreign matter in fuel

Actions (chapter)
Inspect or reinstall (see chapter 16).
Inspect (see chapter 16).
Inspect and replace (see chapter 16).
Replace it with the correct plug (see chapter 2).
Inspect (see chapter 3).

Clean element or inspect sealing (see chapter 2).
Reinstall (see chapter 3).
Reinstall (see chapter 3).
Replace (see chapter 3).
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 DFI Fuel pump bearings may wear. Replace the fuel
fuse blows.
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 Inspect and repair or replace (see chapter 3).
vacuum hose
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).
Throttle valves will not fully open
Inspect throttle cables and lever linkage (see
chapter 3).
Engine overheating - Water temperature sensor (see Overheating of Troubleshooting Guide in
or crankshaft sensor trouble
chapter 17)

FUEL SYSTEM (DFI) 3-39
DFI System Troubleshooting Guide
Symptoms or Possible Causes
Air switching valve trouble
Air suction valve trouble
Exhaust Smokes Excessively:
(Black smoke)
Air cleaner element clogged
Fuel pressure too high
Fuel injector trouble
Water temperature sensor trouble
Intake air temperature sensor trouble
(Brown smoke)
Air duct loose
Fuel pressure too low
Water temperature sensor trouble
Intake air temperature sensor trouble

Actions (chapter)
Inspect and replace (see chapter 16).
Inspect and replace (see chapter 5).

Clean element (see chapter 2).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Reinstall (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).
Inspect (see chapter 3).

3-40 FUEL SYSTEM (DFI)
Self-Diagnosis
Self-Diagnosis Outline
The self-diagnosis system is monitoring the following
mechanisms.
DFI System and Ignition System
The following warning indicator lights (LED) are used for
warning indicators of below table.
LED Color
Red [A]
Yellow [B]

Warning Indicators
Oil Pressure
Battery
Water Temperature
FI

The self-diagnosis system has two 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 or blinking the yellow engine
warning indicator 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 above system
has at the moment of diagnosis.

Self-Diagnosis Procedures

○Use

NOTE

a fully charged battery when conducting
self-diagnosis. Otherwise, the warning indicator light
(LED) and indicator do not light or blink.

the ignition switch on and start the engine.
•○Turn
When a problem occurs with DFI system and ignition system, the yellow engine warning indicator light (LED) [A]
stays on after starting the engine to alert the rider.

FUEL SYSTEM (DFI) 3-41
Self-Diagnosis

• Push the left meter button [A] to display the odometer.

the left meter button [A] for more than two seconds.
• Push
The
service
code [B] is displayed on the LCD by the num• ber of two digits.

of the following procedures ends self-diagnosis.
•○Any
When the service code is displayed on the LCD, push the
left meter button for more than two seconds. The display
will return to the previous display.
○When the ignition switch is turned off.

3-42 FUEL SYSTEM (DFI)
Self-Diagnosis
Self-Diagnosis Flow Chart

FUEL SYSTEM (DFI) 3-43
Self-Diagnosis
Service Code Reading

○The service code(s) 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 left meter button is
pushed for more than two seconds.
○For example, if three problems occurred in the order of
56, 11, 24, the service codes are displayed (each two
seconds) from the lowest number in the order listed as
shown. (11→24→56)→(11→24→56)→· · ·(repeated)

Service Code Erasing

service codes stored in memory of the ECU can be erased using Kawasaki Diagnostic System
• The
(KDS Ver.3).
If the Kawasaki Diagnostic System (KDS Ver.3) is not available, do the following procedures.