Ecu Self-Diagnostic Function - Yamaha YZF-R15 Service Manual

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 fault code number appears on the engine trouble warning
light (or displayed on the FI diagnostic tool). It remains stored in the memory of the ECU until it is
deleted.
1. Engine trouble warning light
Engine trouble warning light fault code indication
Digit of 10: Cycles of 1 sec. ON and 1.5 sec. OFF.
Digit of 1: Cycles of 0.5 sec. ON and 0.5 sec. OFF.
Example: 42
a. Light ON
b. Light OFF
c. 1 sec.
d. 1.5 sec.
e. 0.5 sec.
f. 3 sec.
FUEL INJECTION SYSTEM
1
8-31