Yamaha WR450FB 2012, Owner'S Service Manual

Page: 331 / 392

FUEL INJECTION SYSTEM
9-27
TIP
When the Yamaha diagnostic tool is connected to the vehicle, the operation of the meter and indica-
tors will be different from the normal operation.
EAS1DX3221
ECU SELF-DIAGNOSTIC FUNCTION
The ECU is equipped with a self-diagnostic function in order to ensure that the fuel injection system
is operating normally. If this function detects a malfunction in the system, it immediately operates the
engine under substitute characteristics and illuminates the engine trouble warning light to alert the
rider that a malfunction has occurred in the system. Once a malfunction has been detected, a fault
code number is stored in the memory of the ECU.
• To inform the rider that the fuel injection system is not functioning, the engine trouble warning light
flashes while the start switch is being pushed to start the engine.
• If a malfunction is detected in the system by the self-diagnostic function, the ECU provides an ap-
propriate substitute characteristic operation, and alerts the rider of the detected malfunction by illu-
minating the engine trouble warning light.
• After the engine has been stopped, the lowest fault code number appears on the clock LCD. Once
a fault code has been displayed, it remains stored in the memory of the ECU until it is deleted.
Engine trouble warning light indication and fuel injection system operation
* The warning light flashes when any one of the following conditions is present and the start switch
is pushed:
Warning light indica-
tion
ECU operation
Fuel injection opera-
tion
Vehicle operation
Flashing* Warning provided
when unable to start
engine
Operation stopped Cannot be operated
Remains on Malfunction detected Operated with substi-
tute characteristics in
accordance with the
description of the mal-
function
Can or cannot be oper-
ated depending on the
fault code
12: Crankshaft position sensor 41: Lean angle sensor
(open or short circuit)
30: Lean angle sensor
(latch up detected)
50: ECU internal malfunction
(faulty ECU memory)
33: Ignition coil
(Malfunction detected in the primary wire
of the ignition coil)