Self-Diagnosis Function (Gsf650/S/A/Sak7) - Suzuki GSF650A Service Manual

Compensation of Injection Time (Volume)
The following different signals are output from the respective sensors for compensation of the fuel injection time
(volume).
Signal
ENGINE COOLANT TEMPERATURE SENSOR
SIGNAL
INTAKE AIR TEMPERATURE SENSOR SIGNAL
HEATED OXYGEN SENSOR SIGNAL
BATTERY VOLTAGE SIGNAL
ENGINE RPM SIGNAL
STARTING SIGNAL
ACCELERATION SIGNAL/ DECELERATION
SIGNAL
Injection Stop Control
Signal
TIP-OVER SENSOR SIGNAL (FUEL SHUT-OFF)
OVER-REV. LIMITER SIGNAL

Self-Diagnosis Function (GSF650/S/A/SAK7)

The self-diagnosis function is incorporated in the ECM. The function has two modes, "User mode" and "Dealer mode".
The user can only be notified by the LCD (DISPLAY) panel and LED (FI indicator light). To check the function of the
individual FI system devices, the dealer mode is provided. In this check, the special tool is necessary to read the code
of the malfunction items.
User Mode
Malfunction
"NO"
Engine can start
"YES"
Engine can not start
*1
When one of the signals is not received by ECM, the fail-safe circuit works and injection is not stopped. In this case,
"FI" and odometer are indicated in the LCD panel and motorcycle can run.
*2
The injection signal is stopped, when the crankshaft position sensor signal, tip-over sensor signal, ignition signal, #1,
#2, #3 and #4 injector signals, fuel pump relay signal or ignition switch signal is not sent to ECM. In this case, "FI" is
indicated in the LCD panel. Motorcycle does not run.
"CHEC":
The LCD panel indicates "CHEC" when no communication signal from the ECM is received for 5 seconds and more.
When engine coolant temperature is low, injection time (volume)
is increased.
When intake air temperature is low, injection time (volume) is
increased.
Air/fuel ratio is compensated to the theoretical ratio from density
of oxygen in exhaust gasses. The compensation occurs in such a
way that more fuel is supplied if detected air/fuel ratio is lean and
less fuel is supplied if it is rich.
ECM operates on the battery voltage and at the same time, it
monitors the voltage signal for compensation of the fuel injection
time (volume). A longer injection time is needed to adjust injection
volume in the case of low voltage.
At high speed, the injection time (volume) is increased.
When starting engine, additional fuel is injected during cranking
engine.
During acceleration, the fuel injection time (volume) is increased,
in accordance with the throttle opening speed and engine rpm.
During deceleration, the fuel injection time (volume) is decreased.
When the motorcycle tips over, the tip-over sensor sends a signal
to the ECM. Then, this signal cuts OFF current supplied to the fuel
pump, fuel injectors and ignition coils.
The fuel injector stops operation when engine rpm reaches rev.
limit rpm.
LCD (display) indication
"A"
Odometer
Odometer and "FI" letters
*1
"FI" letters
*2
Engine General Information and Diagnosis:
Descriptions
Descriptions
FI indicator light
indication "B"
—
FI indicator light turns ON.
FI indicator light turns ON
and blinks.
1A-2
B817H21101002
Indication mode
—
Each 2 sec. Odometer or
"FI" is indicated.
"FI" is indicated
continuously.