Fail-Safe Function - Suzuki TU250X Service Manual

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
IAT sensor
ET sensor
HO2 sensor
STV actuator
STP sensor
PAIR control solenoid 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.
FAIL-SAFE MODE
Intake air pressure is fixed to 101.3
kPa (760 mmHg).
The throttle opening is fixed to full
open position.
Ignition timing is also fixed.
Intake air temperature value is fixed
to 40 °C (104 °F).
Engine temperature value is fixed to
90 °C (194 °F).
Feedback compensation is inhibited.
(Air/fuel ratio is fixed to normal.)
When motor disconnection or lock
occurs, power from ECM is shut off.
Secondary throttle valve is fixed to
full open position.
ECM stops controlling PAIR control
solenoid valve.
FI SYSTEM DIAGNOSIS 4-17
STARTING RUNNING
ABILITY ABILITY
"YES" "YES"
"YES" "YES"
"YES" "YES"
"YES" "YES"
"YES" "YES"
"YES" "YES"
"YES" "YES"
"YES" "YES"