Ecu Self-Diagnostic Function - Yamaha MT-01 T 2005 Service Manual

EAS27350

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 en-
gine 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.
• 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 provides an appro-
priate substitute characteristic operation, and alerts the rider of the detected malfunction by illuminat-
ing the engine trouble warning light.
• After the engine has been stopped, the lowest fault code number appears on the odometer/tripme-
ter/fuel reserve tripmeter 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
Warning light indica-
tion
Flashing*
Remains on
* The warning light flashes when any one of the conditions listed below is present and the start switch
is pushed:
12: Crankshaft position sensor
Blue/yellow ECU lead
19:
(broken or disconnected)
Lean angle cut-off switch
30:
(latch up detected)
Checking the engine trouble warning light bulb
The engine trouble warning light comes on for 1.4 seconds after the main switch has been turned to
"ON" and it comes on while the start switch is being pushed. If the warning light does not come on under
these conditions, the warning light bulb may be defective.
ECU operation
Warning provided
when unable to start
engine
Fault code No. 63
detected
Malfunction detected
FUEL INJECTION SYSTEM
Fuel injection opera-
tion
Operation stopped
Operates
Operated with
substitute
characteristics in
accordance with the
description of the
malfunction
Lean angle cut-off switch
41:
(open or short-circuit)
ECU internal malfunction
50:
(memory check error)
7-27
Vehicle operation
Cannot be operated
Can be operated
Can or cannot be
operated depending on
the fault code