Yamaha RX10LTGTAX, Service Manual

Page: 295 / 1664

FI
SUBSTITUTE CHARACTERISTICS OPERATION CONTROL (FAIL-SAFE ACTION)
If the ECU detects an abnormal signal from a sensor while the vehicle is being driven, the ECU illu-
minates the engine trouble warning light and provides the engine with alternate operating instruc-
tions that are appropriate for the type of malfunction.
When an abnormal signal is received from a sensor, the ECU processes the specified values that
are programmed for each sensor in order to provide the engine with alternate operating instructions
that enable the engine to continue to operate or stop operating, depending on the conditions.
The ECU takes fail-safe actions in two ways: one in which the sensor output is set to a prescribed
value, and the other in which the ECU directly operates an actuator. Details on the fail-safe actions
are given in the table below.
FAIL-SAFE ACTIONS TABLE
Fault
Code No.
Item Symptom Fail-
S
afe
A
ction
Starting
Capability
Running
Capability
11
Cylinder identification
sensor No normal signals are received
from the cylinder identification
sensor. Continues to operate the engine
based on the results of the
cylinder identification that
existed up to that point.
Unable Able
12
Crankshaft position
sensor No normal signals are received
from the crankshaft position
sensor. • Stops the engine (by stopping
the injection and ignition). Unable Unable
13
14
Intake air pressure
sensor (open or short
circuit) (pipe system) Intake air pressure sensor-open
or short circuit detected.
Faulty intake air pressure sensor
system. • Fixes the intake air pressure to
85.0 k
P
a.
Able Able
15
16
Throttle position sensor
(open or short circuit)
(stuck) Throttle position sensor-open or
short circuit detected. • Fixes the throttle position
sensor to fully open. Able Able
20
Intake air pressure
Atmospheric pressure Defective values are detected
due to the internal malfunction. • Fixes the intake air pressure
and atmospheric pressure to
85.0 k
P
a.
Able Able
21
Coolant temperature
sensor Coolant temperature sensor-
open or short circuit detected. • Fixes the coolant temperature
to 60°C.
After the engine starts,
Able Able
22
Intake temperature
sensor Intake temperature sensor-open
or short circuit detected. • Fixes the intake temperature to
0°C.
Able Able
23
Atmospheric pressure
sensor (open or short
circuit) Atmospheric pressure sensor-
open or short circuit detected. • Fixes the atmospheric
pressure to 85.0 k
P
a. Able Able
30
Oil pressure dropped Engine stops when the oil
pressure drop is detected. • Fuel pump and fuel injection
are stopped. (Main relay is off.)
Unable Unable
33
34
35
36
Faulty ignition Open circuit detected in the
primary lead of the ignition coil. • Cut the injection of other
cylinder in the same group with
the cylinder that the error is
detected.
(Example: when the #1
cylinder is detective, cut the
injection of #1 and #4
cylinders, when the #2 cylinder
is detective, cut the injection of
#2 and #3 cylinders).
Turn on the power to the air
induction solenoid to always
cut-off the air.
Able
(depending
on the
number of
faulty
cylinders)
Able
(depending
on the
number of
faulty
cylinders)
42
Speed sensor No normal signals are received
from the speed sensor
.
•
Assumes highest ratio.
Able Able
43
Fuel system voltage
(monitor voltage) The ECU is unable to monitor
the battery voltage (an open
circuit in the line to the ECU). • Fixes the battery voltage to 12 V.
Able Able
FUEL INJECTION SYSTEM
61
the radiator fan relay will be
turned ON.