Fail-Safe Function - Suzuki GW250 Service Manual

4-20 FI SYSTEM DIAGNOSIS

FAIL-SAFE FUNCTION

FI system is provided with fail-safe function to allow the engine to start and the motorcycle to run in a mini-
mum performance necessary even under malfunction condition.
ITEM
IAP sensor
TP sensor
ECT sensor
IAT sensor
Ignition signal
Injection signal
Gear position signal
HO2 sensor
PAIR control solenoid valve
ISC valve
The engine can start and can run even if the above signal is not received from each sensor. But, the engine
running condition is not complete, providing only emergency help (by fail-safe circuit). In this case, it is nec-
essary to bring the motorcycle to the workshop for complete repair.
When two ignition signals or two injector signals are not received by ECM, the fail-safe circuit can not work
and ignition/injection is stopped.
FAIL-SAFE MODE
Intake air pressure is fixed to 101
kPa (760 mmHg).
The throttle opening is fixed to full
open position.
Ignition timing is also fixed.
Engine coolant temperature value is
fixed to 80 °C (176 °F).
Cooling fan is fixed on position.
Intake air temperature value is fixed
to 40 °C (104 °F).
#1 fuel-cut
#2 fuel-cut
—
—
Gear position signal is fixed to 6th
gear.
Feedback compensation is inhibited.
(Air/fuel ratio is fixed to normal.)
ECM stops controlling PAIR control
solenoid valve.
When motor disconnection or lock
occurs, power from ECM is shut off.
STARTING RUNNING
ABILITY ABILITY
"YES" "YES"
"YES" "YES"
"YES" "YES"
"YES" "YES"
"YES" "YES"
#2 cylinder can run.
"YES" "YES"
#1 cylinder can run.
"YES" "YES"
#2 cylinder can run.
"YES" "YES"
#1 cylinder can run.
"YES" "YES"
"YES" "YES"
"YES" "YES"
"YES" "YES"