Yamaha YP400T Service Manual page 304

Fault code No. 13 Symptom
Used diagnostic code No. 03 (intake air pressure sensor)
Order Inspection operation item and
probable cause
1 Connected condition of connector
Inspect the coupler for any pins
that may have pulled out.
Check the locking condition of the
coupler.
NOTE:
Set the main switch to OFF before
connecting or disconnecting the
connector.
2 Open or short circuit in wiring har-
ness and/or sub lead.
3 Defective intake air pressure sen-
sor
FUEL INJECTION SYSTEM
Intake air pressure sensor - open or short circuit detected.
Operation item and countermeasure
If there is a malfunction, repair it and connect it
securely.
Intake air pressure 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
pink/white – pink/white
blue – blue
Execute the diagnostic mode (code No. 03)
Replace if defective.
1. Connect the pocket tester (DC 20 V) to the intake
air pressure sensor coupler as shown.
Positive tester probe → pink/white 1
Negative tester probe → black/blue 2
2. Set the main switch to "ON".
3. Measure the intake air pressure sensor output
voltage.
Intake air pressure sensor output
voltage
3.4 ~ 3.8 V
4. Is the intake air pressure sensor OK?
7 - 14
FI
Reinstatement
method
Reinstated by turn-
ing the main switch
ON.