Ecu Self-Diagnostic Function; Troubleshooting Method - Yamaha 2014 MT-07 Service Manual

EAS30505

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
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 " " side of the start/engine stop 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 meter display. This
number remains stored in the memory of the ECU until it is deleted.
Engine trouble warning light indication and fuel injection system operation
Warning light indication
Flashing*
Remains on
* The warning light flashes when any one of the following conditions is present and the " " side of the
start/engine stop switch is pushed:
12: Crankshaft position sensor
Black/red ECU lead
19:
(broken or disconnected)
Lean angle sensor
30:
(latch up detected)
Checking the engine trouble warning light
The engine trouble warning light comes on for around 2 seconds after the main switch has been set to
"ON" and it comes on while the " " side of the start/engine stop switch is being pushed. If the warning
light does not come on under these conditions, the warning light (LED) may be defective.
ECU detects an abnormal signal from a sensor
If the ECU detects an abnormal signal from a sensor while the vehicle is being driven, the ECU illumi-
nates the engine trouble warning light and provides the engine with alternate operating instructions 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 operating or stop operating, depending on the conditions.
EAS30506

TROUBLESHOOTING METHOD

The engine operation is not normal and the engine trouble warning light comes on.
1. Check:
• Fault code number
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a. Check the fault code number displayed on the meter.
ECU operation
Warning provided when
unable to start engine
Malfunction detected
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FUEL INJECTION SYSTEM
Fuel injection operation
Operation stopped
Operated with substitute
characteristics in accor-
dance with the descrip-
tion of the malfunction
Lean angle sensor
41:
(open or short circuit)
ECU internal malfunction
50:
(memory check error)
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8-35
Vehicle operation
Cannot be operated
Can or cannot be operat-
ed depending on the fault
code
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