Yamaha YZF-R1 Series Service Manual page 546

SELF-DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE
DTC Item
P1602 Malfunction in ECU
internal circuit (mal-
function of ECU pow-
er cut-off function).
P1806 [P1806] Shift sensor:
P1807 open or ground short
circuit detected.
[P1807] Shift sensor:
power short circuit de-
tected.
P2122 [P2122] Accelerator
P2123 position sensor: open
P2127 or ground short cir-
P2128 cuit detected.
P2138 [P2123] Accelerator
position sensor: pow-
er short circuit detect-
ed.
[P2127] Accelerator
position sensor: open
or ground short cir-
cuit detected.
[P2128] Accelerator
position sensor: pow-
er short circuit detect-
ed.
[P2138] Deviation er-
ror
Probable cause of
malfunction
• Open or short cir- Engine idling speed is
cuit in wire harness unstable.
between ECU and Engine idling speed is
battery. high.
• Open or short cir- Increased exhaust
cuit in wire harness emissions.
between ECU and Engine is difficult to
main switch. start.
• Blown backup fuse.
• Malfunction in ECU.
• Defective coupler Unable to carry out
between shift sensor QSS.
and ECU. (If this abnormality oc-
• Open or power short curs during actual
circuit in wire har- shifting, the operation
ness between shift will be carried out until
sensor and ECU. the process is com-
• Improperly installed pleted.)
shift sensor.
• Defective shift sen-
sor.
• Malfunction in ECU.
[P2122, P2127] Low Engine response is
poor.
voltage of the acceler-
ator position sensor Loss of engine power.
circuit (0.25 V or less) Engine idling speed is
[P2123, P2128] High unstable.
voltage of the acceler-
ator 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 harness
between accelera-
tor position sensor
and ECU.
• Improperly installed
accelerator position
sensor.
• Defective accelera-
tor position sensor.
• Malfunction in ECU.
9-49
Fail-safe system op-
Vehicle symptom
O
2
is not carried out.
O
2
value is not written.
QSS is not carried
out.
No change in acceler-
ator opening (tran-
sient control is not
carried out).
Accelerator opening is
fixed to 0[°].
O
2
carried out.
YCC-T evacuation is
activated.
Fuel cut is prohibited
by accelerator open-
ing.
Output is restricted.
ISC feedback is not
carried out.
ISC learning is not
carried out.
QSS is not carried
out.
eration
feedback learning
feedback learning
feedback is not