ignition YAMAHA YZ450F 2011 Owner's Manual

7-6
THROTTLE POSITION SENSOR SYSTEM
THROTTLE POSITION SENSOR SYSTEM
INSPECTION STEPS
If the throttle position sensor will not operate, use the following inspection steps.
*marked: Refer to "IGNITION SYSTEM" section.
Use the following special tools in this inspection.
Check entire ignition system for connection. No good→Repair or replace.
OK↓
Check throttle position sensor. No good→Replace.
OK↓
*Check AC magneto. No good→Replace.
OK↓
Check ECU. (Throttle position sensor input volt-
age)No good→
Replace.
Model 88 Multimeter with tacometer:
YU-A1927
Digital circuit tester:
90890-03174
Test harness-speed sensor (3P):
YU-03208/90890-03208

7-11
FUEL INJECTION SYSTEM
SENSOR OPERATION TABLE
Diagnos-
tic code
No.ItemActuation or
displayChecking methodActuation or LCD standard display
values
D01 Throttle angle DisplayDisplays the throttle angle. 0–125°
Check with throttle fully closed. When throttle is fully closed:15–19°
Check with throttle fully open. When throttle is fully
opened:95–101 °
D02 Atmosphere DisplayDisplays the atmospheric pres-
sure.
• Measure the atmospheric pres-
sure.0–126 kPa
Displays the atmospheric pressure
according to the elevation and
weather.
Example
0 m above sea level: Approx: 101
kPa
3000 m above sea level:Approx: 70
kPa
D03 Intake air pressure DisplayDisplays the intake air pressure.
• Check the intake manifold pres-
sure.
• Check that the intake air pres-
sure changes while the engine is
being cranked.0–126 kPa
While the engine is stopped: Dis-
plays the atmospheric pressure ac-
cording to the elevation and
weather.
Example
0 m above sea level: Approx: 101
kPa
3000 m above sea level:Approx: 70
kPa
While the engine is being cranked:
Displays the intake air pressure.
D05 Intake air temperature DisplayDisplays the intake air tempera-
ture.
• Check the temperature in the in-
take manifold.-20–100°C
Cold engine: Displayed tempera-
ture is close to the ambient temper-
ature.
Warm engine: Displayed tempera-
ture is approximately 20 °C higher
than the ambient temperature.
D06 Coolant temperature DisplayDisplays the coolant temperature.
• Check the coolant temperature.-20–150°C
Cold engine: Displayed tempera-
ture is close to the ambient temper-
ature.
Warm engine: Displayed tempera-
ture is the current coolant tempera-
ture.
D08 Lean angle sensor DisplayDisplays the lean angle sensor
output voltage.
Remove the ECU and incline it 45°
or more.0–5.0 V
1.0 V: Upright
4.0 V: Overturned
D30 Ignition coil ActuationCheck that power is supplied to
the ignition coil.
• Check that a spark is generated.
• Illuminates the engine trouble
warning light.Actuates the ignition coil for five
times every second.
The "WARNING" LED on the FI di-
agnostic tool comes on each time
the fuel injector is actuated.

7-12
FUEL INJECTION SYSTEM
D36 Injectors ActuationCheck that power is supplied to
the fuel injector.
• Check the fuel injector operation
by listening for the operating
sound or by confirming the oper-
ation visually.Actuates the injector for five times
every second.
The "WARNING" LED on the FI di-
agnostic tool comes on each time
the fuel injector is actuated.
D60EEPROM fault code
display.DisplayDisplays the abnormal portion of
the data in the EEPROM that has
been detected as a fault code No.
44.
If code numbers more than one
are detected, the display alter-
nates every two seconds to show
all the detected code numbers.
When all code numbers are
shown, the display repeats the
same process.00: No fault
01: CO adjustment valve
07: Power Tuner adjustment val-
ues 0–8 for fuel injection amount or
ignition timing
D61Malfunction history
code display.DisplayDisplays the fault code numbers
that are stored in the malfunction
history.
If code numbers more than one
are detected, the display alter-
nates every two seconds to show
all the detected code numbers.
When all code numbers are
shown, the display repeats the
same process.00: No history
12–50: History exists
• Refer to the fault code number.
D62Malfunction history
code erasureActuation
and displayDisplays the total number of mal-
functions, including the current
malfunction, that have occurred
since the history was last erased.
In addition, deletes the fault code
numbers from the history if the cor-
responding items are currently op-
erating normally.00: No history
1–15: History exists
When this diagnostic code number
is selected, fault code numbers for
previously detected malfunctions
are deleted from the history if the
corresponding items are currently
operating normally.
D64 Setting history display DisplayDisplays whether or not history ex-
ists for settings that were made us-
ing the Power Tuner.00: There is no setting history.
01: There is setting history.
02: Whether or not setting history
data exists cannot be determined
(damage to history data).
D65 Setting map erasure DisplayErases the settings that were
made using the Power Tuner.00: There are no settings that were
made using the Power Tuner.
01: There are settings that were
made using the Power Tuner.
D70Program version
numberDisplayCheck the version number of the
program.0–254 Diagnos-
tic code
No.ItemActuation or
displayChecking methodActuation or LCD standard display
values

7-26
FUEL INJECTION SYSTEM
Fault code No. 33
Symptom Ignition system circuit signal is not received properly.
Fail-safe system Unable to start
Unable to drive
Diagnostic code No. D30
FI diagnostic tool display Actuates the ignition coil for five times every second.
The "WARNING" LED on the FI diagnostic tool comes on each time the ignition coil is ac-
tuated.
Checking methodCheck the spark five times.
• Connect an ignition checker.
Item Item/components and probable cause Check or maintenance job Checking method
1 Check the connection and locking condition of
the ignition coil coupler.
Disconnect the coupler and check the pins.
(bent or broken terminals and locking condition
of the pins)Poor connection→ Properly con-
nect, repair, or replace.Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 2.
2 Check the connection and locking condition of
the wire harness ECU coupler.
Disconnect the coupler and check the pins.
(bent or broken terminals and locking condition
of the pins)Poor connection → Properly con-
nect, repair, or replace.Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 3.
3 Continuity of harness Open or short circuit → Replace.
Between Ignition coil coupler and
ECU coupler.
(Orange–Orange)Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 4.

7-27
FUEL INJECTION SYSTEM
4 Installed condition of ignition coil Check that the sensor is installed
securely and that there are no
pinched leads.Check that the ECU
is installed securely and that there
are no pinched leads.
Incorrect installation → Reinstall
or repair.Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 5.
5 Defective ignition coil. (test the primary coils for
continuity)Defective → Replace.
Refer to "CHECKING THE IGNI-
TION COIL".Start the engine and let it
idle for approximately 5
seconds.
After completing the above
operation, check whether a
fault code number is dis-
played.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 6.
6 Malfunction in ECU. Execute the diagnostic mode (di-
agnostic code No. D30).
No spark → Replace the ECU. Fault code No. 33
Symptom Ignition system circuit signal is not received properly.
Fail-safe system Unable to start
Unable to drive
Diagnostic code No. D30
FI diagnostic tool display Actuates the ignition coil for five times every second.
The "WARNING" LED on the FI diagnostic tool comes on each time the ignition coil is ac-
tuated.
Checking methodCheck the spark five times.
• Connect an ignition checker.
Item Item/components and probable cause Check or maintenance job Checking method

7-30
FUEL INJECTION SYSTEM
Fault code No. 44
Symptom Error is detected while reading or writing on EEPROM.
Fail-safe system Able to start engine (depending on circumstances)
Able to drive vehicle (depending on circumstances)
Diagnostic code No. D60
FI diagnostic tool display 00: No fault
01: CO adjustment valve
07: Power Tuner adjustment values 0–8 for fuel injection amount or ignition timing
Checking method —
Item Item/components and probable cause Check or maintenance job Checking method
1 Determine the area of the problem Execute the diagnostic mode (di-
agnostic code No. D60).
00 is displayed: Refer to item 4.
01 is displayed: Refer to item 2.
07 is displayed: Refer to item 3.Set the switch on the FI di-
agnostic tool sub-wire har-
ness to "ON", and then
check the fault code dis-
play.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Repeat item 1.
If the fault code number
is still displayed, refer to
item 3.
2 EEPROM data error (CO adjustment value) Change the CO density and write
the changed setting on EEPROM.Set the switch on the FI di-
agnostic tool sub-wire har-
ness to "ON", and then
check the fault code dis-
play.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Repeat item 1.
If the fault code number
is still displayed, refer to
item 4.
3 EEPROM data error (Power Tuner adjustment
values for fuel injection amount or ignition tim-
ing)Erase the setting map in the diag-
nostic mode (diagnostic code No.
D65).Set the switch on the FI di-
agnostic tool sub-wire har-
ness to "ON", and then
check the fault code dis-
play.
Fault code number is not
displayed → Service is
finished.
Fault code number is dis-
played → Refer to item 1.
4 Malfunction in ECU. Replace the ECU.