Yamaha F400A 2022 - Fail-Safe

Electronic control system
2-38
Fail-safe
In the fail-safe control, the engine ECM enters the fail-safe control mode when an electrical component
malfunctions.
The fail-safe control system records the trouble codes according to the engine trouble conditions.
*: For applications with multiple outboard motors
Item Trouble conditions to be detected Controls performed by ECM
Crankshaft position
sensor
There are 7 signals from cam posi-
tion sensor (PORT EX), but no sig-
nal from crankshaft position sensor.
Set VCT in full retard position.
Stop engine synchronization con-
trol.*
Cam position sensor
(PORT EX)
No signal from cam position sensor
(PORT EX) for 1 second.
High engine idle speed.
Ignition timing advance angle is lim-
ited to BTDC 10°.
Perform cylinder position identifica-
tion using cam position sensor
(PORT IN).
Set VCT in full retard position.
Stop engine synchronization con-
trol.*
Cam position sensor
(STBD IN)
No signal from cam position sensor
(STBD IN) for 1 second.
High engine idle speed.
Set VCT in full retard position.
Stop engine synchronization con-
trol.*
Cam position sensor
(PORT IN)
No signal from cam position sensor
(PORT IN) for 1 second.
High engine idle speed.
Perform cylinder position identifica-
tion using cam position sensor
(PORT EX).
Set VCT in full retard position.
Stop engine synchronization con-
trol.*
TPS
TPS 1 output voltage is 0.35 V or
less or 4.80 V or more. TPS 2 output
voltage is 2.25 V or less or 4.80 V or
more.
Engine speed is limited to 4200 r/
min.
Stop engine synchronization con-
trol.*
Difference between TPS 1 and TPS
2 voltages is 1.7 V or less or 2.30 V
or more.
Engine speed is limited to 1500 r/
min.
Stop engine synchronization con-
trol.*
Intake air pressure
sensor
Output voltage is less than 0.20 V or
more than 4.80 V.
High engine idle speed.
Stop engine synchronization con-
trol.*
Engine temperature
sensor
Output voltage is less than 0.20 V or
more than 4.80 V.
Set to intake air temperature when
starting.
Set to 40 °C (104 °F) when running.
High engine idle speed.
Set VCT in full retard position.
Stop engine synchronization con-
trol.*