7-21
FUEL INJECTION SYSTEM
Make sure that the engine is completely cool before checking the intake air temperature sensor.
5 Defective coolant temperature sensor. Execute the diagnostic mode (di-
agnostic code No. D06).
Cold engine: Displayed temper-
ature is close to the ambient
temperature.
Displayed value is incorrect → Re-
place. 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 6.
6 Malfunction in ECU. Replace the ECU.
Fault code No. 22
Symptom Intake air temperature sensor signal is not received properly.
Fail-safe system Able to start Able to drive
Diagnostic code No. D05
FI diagnostic tool display -20–100°C Cold engine: Displayed temperature is close to the ambient temperature.
Warm engine: Displayed temperature is approx imately 20°C higher than the ambient tem-
perature.
Checking method Check the temperature in the intake manifold. Item Item/components and probable cause Check or maintenance job Checking method
1 Check the connection and locking condition of the intake air temperature sensor 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. 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 2.
Fault code No. 21
Symptom Coolant temperature sensor signal is not received properly.
Fail-safe system Able to start
Able to drive
Diagnostic code No. D06
FI diagnostic tool display -20–150°C Cold engine: Displayed temperature is close to the ambient temperature.
Warm engine: Displayed temperature is the current coolant temperature.
Checking method Check the coolant temperature. Item Item/components and probable cause Check or maintenance job Checking method
7-36
ELECTRICAL COMPONENTS
ELECTRICAL
COMPONENTS
CHECKING THE COOLANT
TEMPERATURE SENSOR
1. Remove:
•Coolant temperature sensor
Refer to "REMOVING THE CYL-
INDER HEAD" section in the
CHAPTER 4.
•Handle the coolant temperature
sensor with special care.
•Never subject the coolant tem-
perature sensor to strong
shocks. If the coolant tempera-
ture sensor is dropped, replace
it.
2. Check:
• Coolant temperature sensor re-
sistance
3. Connect:
•Tester
Tester (+) lead → Brown lead "1"
Tester (-) lead → Black/Blue lead
"2"
4. Immerse the coolant temperature
sensor in a container filled with
coolant.
Make sure the coolant temperature
sensor terminals do not get wet.
5. Place a thermometer "3" in the
coolant.
6. Slowly heat the coolant, and then
let it cool to the specified temper-
ature indicated in the table.Out of specification → Replace.
CHECKING THE INTAKE AIR
PRESSURE SENSOR
1. Check:
• Intake air pressure sensor output
voltage
2. Connect:
• Test harness S–pressure sensor
(3P) "1"
•Tester
Tester (+) lead → Pink/White lead
(wire harness color)
Tester (-) lead → Black/Blue lead
(wire harness color)
3. Connect the FI diagnostic tool
sub-wire harness to a battery, and
then set the switch on the harness
to "ON".
When checking the intake air pres-
sure sensor, do not start the en-
gine.
4. Measure the intake air pressure
sensor output voltage.
Out of specification → ReplaceCHECKING THE INTAKE AIR
TEMPERATURE SENSOR
1. Remove:
• Intake air temperature sensor
(from the air filter case.)
•Handle the intake air temperature
sensor with special care.
•Never subject the intake air tem-
perature sensor to strong
shocks. If the intake air tempera-
ture sensor is dropped, replace
it.
2. Check:
• Intake air temperature sensor re-
sistance
3. Connect:
•Tester
Tester (+) lead → Brown/White
lead "1"
Tester (-) lead →Black/Blue lead
(wire harness color) "2"
Out of specification → Replace.
CHECKING THE ATMOSPHERIC
PRESSURE SENSOR
1. Check:
• Atmospheric pressure sensor out-
put voltage
2. Connect:
• Test harness S- pressure sensor
(3P) "1"
•Tester
Tester (+) lead → Pink lead (wire
harness color)
Tester (-) lead → Black/Blue lead
(wire harness color)
B/L Br
Coolant
tempera-
ture sensor
resistanceTester se-
lector posi-
tion
210–220 Ω
(100°C,
212°F)Ω×100
2.51–2.78
kΩ (20°C,
68°F)kΩ×1
Test harness S–pressure
sensor (3P)
YU-03207/90890-03207
Output volt-
ageTester se-
lector posi-
tion
3.4–3.8 V DCV
Intake air
tempera-
ture sensor
resistanceTester se-
lector posi-
tion
5.4–6.6 kΩ
(0°C, 32°F)kΩ×1
290–390 Ω
(80°C,
176°F)Ω×100
Br/WB/L
