Kawasaki STX-15F - Manual (Page 78)

3-24 FUEL SYSTEM (DFI)
Self-Diagnosis
Note:
(1) D-J Method: the DFI control method from medium to heavy engine load. When the engine load
is light like at idling or low speed, the ECU determines the injection quantity by calculating from
the throttle vacuum (vacuum sensor output voltage) and engine speed (crankshaft sensor output
voltage).
(2) α-N Method: As the engine speed increases, and the engine load turns middle to heavy, the ECU
determines the injection quantity by calculating from the throttle opening (throttle sensor output
voltage) and the engine speed.
(3) If both throttle sensor system and inlet air pressure fails, the ECU locks ignition timing into the
ignition timing at closed throttle position and sets the DFI in the α-N method.
(4) The ECU may be involved in these problems. If all the parts and circuits checked out good, be
sure to check the ECU for ground and power supply. If the ground and power supply are checked
good, replace the ECU.
Memory of Service Code (Character)
The service codes (characters) in the past are stored in the ECU. However, the characters cannot be
displayed in the meter. The past service codes can be confirmed by using the Kawasaki Diagnostic
System (see General Information chapter), and they can be erased.