Yamaha YP400T Service Manual page 307

Fault code No. 22 Symptom
Used diagnostic code No. 05 (intake air temperature sensor)
Order Inspection operation item and
probable cause
1 Installed condition of sensor
2 Connected condition of connector
Inspect the coupler for any pins
that may have pulled out.
Check the locking condition of the
coupler.
3 Open or short circuit in wiring har-
ness and/or sub lead.
4 Defective intake air temperature
sensor.
FUEL INJECTION SYSTEM
Intake temperature sensor open or short circuit is detected.
Operation item and countermeasure
Check the installed area for looseness or pinching.
If there is a malfunction, repair it and connect it
securely.
Intake air temperature sensor coupler
Main wiring harness ECU coupler
Sub-wire harness coupler
Repair or replace if there is an open or short circuit.
Between sensor coupler and ECU coupler
black/blue – black/blue
brown/white – brown/white
Execute the diagnostic mode (code No. 05)
Replace if defective.
1. Remove the intake air temperature sensor from
the air filter case.
2. Connect the pocket tester (Ω × 100) to the intake
air temperature sensor terminal as shown.
Positive tester probe → brown/white 1
Negative tester probe → black/blue 2
2 1
3. Measure the intake air temperature sensor resis-
tance.
Intake air temperature sensor
resistance
2.3 ~ 2.6 kΩ at 20 °C (68 °F)
WARNING
• Handle the intake air temperature sensor
with special care.
• Never subject the intake air temperature sen-
sor to strong shocks. If the intake air temper-
ature sensor is dropped, replace it.
4. Is the intake air temperature sensor OK?
7 - 17
FI
Reinstatement
method
Reinstated by turn-
ing the main switch
ON.
Br/W B/L