Yamaha MT-09 2021 Service Manual page 498

SELF-DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE
DTC Item
P1602 Malfunction in ECU
internal circuit (mal-
function of ECU
power cut-off func-
tion).
P1606 [P1606] Intake air
P1607 pressure sensor 2:
P1608 ground short circuit
detected.
[P1607] Intake air
pressure sensor 2:
open or power short
circuit detected.
[P1608] Intake air
pressure sensor 2:
signal out of range.
P1609 Intake air pressure
sensor 2: clogging
of hose or sensor
disconnection
Probable cause of
malfunction
• Open or short cir-
cuit in wire har-
ness between
ECU and battery.
• Open or short cir-
cuit in wire har-
ness between
ECU and main
switch.
• Blown backup
fuse.
• Malfunction in
ECU.
• Defective coupler
between intake air
pressure sensor 2
and ECU.
• Open or short cir-
cuit in wire har-
ness between
intake air pressure
sensor 2 and ECU.
• Improperly in-
stalled intake air
pressure sensor 2.
• Defective intake
air pressure sen-
sor 2.
• Malfunction in
ECU.
• Intake air pressure
sensor 2 hose is
not installed.
• Intake air pressure
sensor 2 hose is
not installed cor-
rectly (Detached,
clogged, kinked or
pinching).
• Intake air pressure
sensor 2 hole is
clogged, or intake
air pressure sen-
sor is not installed
correctly.
9-68
Vehicle symptom
Engine idling speed
is unstable.
Engine idling speed
is high.
Increased exhaust
emissions.
Engine is difficult to
start.
Engine is difficult to
start.
Increased exhaust
emissions.
Insufficient power at
high altitudes.
Engine idling speed
is unstable.
Engine idling speed
is high.
Engine idling speed
is unstable.
Loss of engine pow-
er.
Fail-safe system
operation
feedback learn-
O
2
ing is not carried
out.
O feedback learn-
2
ing value is not writ-
ten.
Cruise control sys-
tem cannot be oper-
ated. (for
MTN890D)
α–N is fixed.
Intake air pressure
difference is fixed to
0 [kPa].
Atmospheric pres-
sure is fixed to
101.3 [kPa].
Fuel is not cut off
due to the intake air
pressure difference.
O feedback is not
2
carried out.
ISC feedback is not
carried out.
ISC learning is not
carried out.
Intake air pressure
difference is fixed to
0 [kPa].
α–N is fixed.
Fuel is not cut off
due to the intake air
pressure difference.
Atmospheric pres-
sure is fixed to
101.3 [kPa].
O feedback is not
2
carried out.