Yamaha XP500, Service Manual

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FI
FUEL INJECTION SYSTEM
EAS00899
ECU (engine) SELF-DIAGNOSTIC FUNCTION
The ECU (engine) is equipped with a self-diagnostic function in order to ensure that the fuel injec-
tion 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 is stored in the memory of the ECU (engine).
• To inform the rider that the fuel injection system is not functioning, the engine trouble warning
light flashes when 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 (engine) pro-
vides an appropriate substitute characteristic operation, and alerts the rider of the detected mal-
function by illuminating 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 (engine) until
it is deleted.
EAS00900
Engine trouble warning light indication and FI system operation
* The warning light flashes when any one of the conditions listed below is present and the start
switch is pushed:
12: Crankshaft position sensor
19: Sidestand switch
(open circuit in the wire to the ECU
(engine))
30: Lean angle cut-off switch
(latch up detected)
41: Lean angle cut-off switch
(open or short-circuit)
50: ECU (engine) internal malfunction
(faulty ECU (engine) memory)
Warning light
indication
ECU (engine) opera-
tion
FI operation Vehicle operation
Flashing* Warning provided
when unable to start
engine Operation stopped Can not be operated
Remains ON Malfunction detected Operated with substi-
tute characteristics in
accordance with the
description of the mal-
function. Can or cannot be
operated depending
on the fault code