Yamaha MTN850-A 2017 Service Manual page 439

Fault code No.
Item
3 Malfunction in ECU.
4 Delete the fault code and check
that the engine trouble warning
light goes off.
Fault code No. P1400
Fault code No.
Item
Fail-safe system
Diagnostic code No.
Actuation
48
Procedure
Probable cause of malfunc-
Item
tion and check
1 Connection of air induction sys-
tem solenoid coupler.
Check the locking condition of
the coupler.
Disconnect the coupler and
check the pins (bent or broken
terminals and locking condition
of the pins).
P1004
Intake air pressure sensor 1 or intake air pressure sensor 2: when
the main switch is turned to "ON", the intake air pressure sensor 1
voltage and intake air pressure sensor 2 voltage differ greatly.
Replace the ECU.
Refer to "REPLACING THE
ECU (Engine Control Unit)" on
page 8-157.
Confirm that the fault code has
a condition of "Recovered"
using the Yamaha diagnostic
tool, and then delete the fault
code.
P1400
Air induction system solenoid: open or short circuit detected.
Able to start engine
Able to drive vehicle
48
Actuates the air induction system solenoid five times at one-second inter-
vals.
The "check" indicator on the Yamaha diagnostic tool screen come on
each time the air induction system solenoid is actuated.
Check that the air induction system solenoid is actuated five times by lis-
tening for the operating sound.
Maintenance job
Improperly connected  Con-
nect the coupler securely or
replace the wire harness.
8-82
FUEL INJECTION SYSTEM
Service is finished.
Confirmation of service com-
Turn the main switch to "ON",
and then check the condition of
the fault code using the mal-
function mode of the Yamaha
diagnostic tool.
Condition is "Recovered"  Go
to item 6 and finish the service.
Condition is "Detected"  Start
the engine and check the status
of the fault code.
Condition is "Recovered"  Go
to item 6 and finish the service.
Condition is "Detected"  Go to
item 2.
TIP
Check that the start/engine stop
switch is turned to "ON" then.
pletion