Ecu Self-Diagnostic Function - Yamaha 2016 Grizzly yfm700gplg Service Manual

EBS30278

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
comes on or 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 multi-function meter
display. Once a fault code has been displayed, it remains stored in the memory of the ECU until it is
deleted.
1. Engine trouble warning light
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 conditions listed below is present and the start switch
" " is pushed:
12: Crankshaft position sensor
Lean angle sensor
30:
(latch up detected)
33: Faulty ignition
Checking for a defective engine trouble warning light bulb
The engine trouble warning light comes on for around 2 seconds after the main switch has been turned
to " " (on). 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.
ECU operation
Warning provided when
unable to start engine
Malfunction detected
FUEL INJECTION SYSTEM
FI operation
Operation stopped
Operated with substitute
characteristics in accor-
dance with the descrip-
tion of the malfunction
Fuel injector
39:
(open or short-circuit)
Lean angle sensor
41:
(open or short-circuit)
ECU internal malfunction
50:
(faulty ECU memory)
9-31
1
Vehicle operation
Cannot be operated
Can or cannot be operat-
ed depending on the fault
code