Troubleshooting Method; Diagnostic Mode - Yamaha YFM70RY Service Manual

Communication error with the meter
Fault
code No.
ECU internal malfunc-
Er-1 tion
(output signal error)
ECU internal malfunc-
Er-2 tion
(output signal error)
ECU internal malfunc-
Er-3 tion
(output signal error)
ECU internal malfunc-
Er-4 tion
(input signal error)
EAS27400

TROUBLESHOOTING METHOD

The engine operation is not normal and the
engine trouble warning light comes on.
1. Check:
• Fault code number
M MMM M MMM M M MMM M
a. Check the fault code number displayed on
the meter.
b. Identify the system with the malfunction. Re-
fer to "Self-Diagnostic Function table".
c. Identify the probable cause of malfunction.
Refer to "Diagnostic code table".
L LLL L LLL L L LLL L
2. Check and repair the probable cause of mal-
function.
Fault code No. YES
Check and repair.
Refer to "TROUBLE-
SHOOTING DE-
TAILS" on page 8-38.
Monitor the opera-
tion of the sensors
and actuators in the
diagnostic mode. Re-
fer to "Sensor opera-
tion table" and
"Actuator operation
table".
EAS27441

DIAGNOSTIC MODE

It is possible to monitor the sensor output data or check the activation of actuators without connecting
the measurement equipment by simply switching the meter indication from the normal mode to the di-
agnostic monitoring mode.
Item
No signals are received from the
ECU.
No signals are received from the
ECU within the specified duration.
Data from the ECU cannot be re-
ceived correctly.
Non-registered data has been re-
ceived from the meter.
M MMM M M MMM M M MMM M
L LLL L L LLL L L LLL L
Fault code No. NO
Check and repair.
Refer to "Self-diag-
nostic function table".
FUEL INJECTION SYSTEM
Symptom
3. Perform ECU reinstatement action.
Refer to "Reinstatement method" of table in
"TROUBLESHOOTING DETAILS".
4. Turn the main switch to "OFF" and back to
"ON", then check the fault code number is not
displayed.
TIP
MMM
If fault codes are displayed, repeat steps (1) to
(4) until no fault code number is displayed.
5. Erase the malfunction history in the diagnos-
tic mode. Refer to "Sensor operation table
(Diagnostic code No.d62)".
LLL
The engine operation is not normal but the
engine trouble warning light does not come
on.
1. Check the operation of following sensors and
actuators in the Diagnostic mode. Refer to
"Sensor operation table" and "Actuator oper-
ation table".
d01: Throttle position sensor (throttle angle)
d30: Ignition coil
d36: Fuel injector
If a malfunction is detected in the sensors or
actuators, repair or replace all faulty parts.
If no malfunction is detected in the sensors
and actuators, check and repair inner parts of
the engine.
8-33
Able / un-
Able / un-
able to
able to start
drive
Unable Unable
Unable Unable
Unable Unable
Unable Unable