Fail-Safe Function Table - Suzuki VLR1800 Service Manual

Fail-Safe Function Table

FI system is provided with fail-safe function to allow the engine to start and the motorcycle to run in a minimum
performance necessary even under malfunction condition.
Item
IAP sensor
TP sensor
ECT sensor
IAT sensor
Ignition signal
STV actuator
STP sensor
Gear position signal
O2 sensor
EXCV actuator
PAIR control solenoid valve
ISC valve
EVAP system purge control
solenoid valve (E-33 only)
The engine can start and can run even if the signal in the table 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 necessary 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
or injection is stopped.
Fail-Safe Mode
Intake air pressure value 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
Secondary throttle valve is fixed to full close
position. When motor disconnection or lock
occurs, power from ECM is shut off.
Secondary throttle valve is fixed to full close
position.
Gear position signal is fixed to 6th gear.
Feedback compensation is inhibited. (Air/
fuel ratio is fixed to normal.)
EXCV actuator is fixed to full open position.
When motor disconnection or lock occurs,
power from ECM is shut off.
ECM stops controlling PAIR control solenoid
valve.
When motor disconnection or lock occurs,
power from ECM is shut off.
ECM stops controlling EVAP system purge
control solenoid valve.
Engine General Information and Diagnosis:
Starting Ability
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
1A-22
B822H11104007
Running Ability
"YES"
"YES"
"YES"
"YES"
"YES"
#2 cylinder can run.
"YES"
#1 cylinder can run.
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"
"YES"