Yamaha MT-09 2021 Service Manual page 499

SELF-DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE
DTC Item
P1806 [P1806] Shift sen-
P1807 sor: open or ground
short circuit detect-
ed.
[P1807] Shift sen-
sor: power short cir-
cuit detected.
P2122 [P2122] Accelerator
P2123 position sensor:
P2127 open or ground
P2128 short circuit detect-
P2138 ed.
[P2123] Accelerator
position sensor:
power short circuit
detected.
[P2127] Accelerator
position sensor:
open or ground
short circuit detect-
ed.
[P2128] Accelerator
position sensor:
power short circuit
detected.
[P2138] Deviation
error
Probable cause of
malfunction
• Defective coupler
between shift sen-
sor and ECU.
• Open or power
short circuit in wire
harness between
shift sensor and
ECU.
• Improperly in-
stalled shift sen-
sor.
• Defective shift
sensor.
• Malfunction in
ECU.
[P2122, P2127] Low
voltage of the accel-
erator position sen-
sor circuit (0.25 V or
less)
[P2123, P2128]
High voltage of the
accelerator position
sensor circuit (4.75
V or more)
[P2138] Difference
in output voltage 1
and output voltage 2
of the accelerator
position sensor
• Defective coupler
between accelera-
tor position sensor
and ECU.
• Open or short cir-
cuit in wire har-
ness between
accelerator posi-
tion sensor and
ECU.
• Improperly in-
stalled accelerator
position sensor.
• Defective acceler-
ator position sen-
sor.
• Malfunction in
ECU.
9-69
Vehicle symptom
Unable to carry out
QSS.
(If this abnormality
occurs during actual
shifting, the opera-
tion will be carried
out until the process
is completed.)
Engine response is
poor.
Loss of engine pow-
er.
Engine idling speed
is unstable.
Fail-safe system
operation
QSS is not carried
out.
No change in accel-
erator opening
(transient control is
not carried out).
Accelerator open-
ing is fixed to 0[°].
O feedback is not
2
carried out.
YCC-T evacuation
is activated.
Fuel cut is prohibit-
ed by accelerator
opening.
Output is restricted.
ISC feedback is not
carried out.
ISC learning is not
carried out.
QSS is not carried
out.
Cruise control sys-
tem cannot be oper-
ated. (for
MTN890D)