Mitsubishi 3000GT Service Manual page 136

LIST OF FAIL-SAFE/BACK-UP FUNCTIONS
When the failure of a major sensor is detected by the on-board diagnostics, the preset control logic
provides controls to assure safe operation of the vehicle.
Trouble item
Volume air flow
(1) Based on throttle position sensor (TPS) signal and engine speed signal (crank angle sensor
sensor
signal) basic driving time of injectors and basic ignition timing is read from the prese
map.
(2) Idle air control motor fixed at predetermined position, and no idling speed control achievec
Intake air temper-
Controls provided on the assumption that intake air temperature is 25% (77°F)
ature sensor
Throttle position
No additional fuel injection provided on the basis of throttle position sensor signal at acceleration
sensor (TPS)
Engine coolant Controls provided on the assumption that engine coolant temperature is 80°C (176°F) (Even if
temperature sen-
the sensor signal returns to normal, this control mode is retained until the ignition switch is set to
sor
OFF.)
Camshaft (1) Fuel injected into the cylinders in the order l-2-3-4-5-6 with irregular timing
position sensor (Provided that no No.1 cylinder top dead center position has been detected since the
ignition switch was placed in the ON position)
(2) Fuel cut 4 seconds after a failure was detected
(Provided that no No.1 cylinder top dead center position has been detected since the
ignition switch was placed in the ON position)
Barometric pres- Controls provided on the assumption that barometric pressure is 101 kPa (760 mmHg) (sea level)
sure sensor
Knock sensor Ignition timing is changed from that for premium gasoline to that for regular gasoline.
Ignition coil and Fuel cut for cylinders whose ignition signal is abnormal
ignition power
transistor unit
No ignition timing retard control (overall engine-transmission control) achieved when transmis-
Communication
line with trans- sion speeds are changed
mission control
module c/VT>
No air-fuel ratio closed loop control achieved
sensor (front) <All
models>
Heated oxygen Only signals of oxygen sensor (front) installed upstream of catalyst are used, and the air-fuel ratio
feedback control (closed loop control) is not performed.
sensor (rear)
cl994 and later
California model>
Controls to be provided in the event of trouble
TSB Revision