1990 MITSUBISHI SPYDER ESP

ENGINE (TURBO)
AND
ENGINE> Troubleshooting
DIAGNOSTIC BY TEST
(INCREASED SENSITIVITY)
When mode II is selected using the MUT-II, the chec k
engine/malfunction indicator lamp illuminates at the point when
the ECM detects a problem (except if the related
to emissions), and at the same time the correspondi ng
diagnostic trouble codes are stored.
Furthermore, in the case of comprehensive component
electrical faults (opens/shorts), the time from the occurrence
of the fault to the storing of the DTC is compresse d (4 seconds
1 second).
As a result of this, checking of the trouble symptoms
checking after have been completed are both made
easier.
Once mode II has been selected, it is necessary
ignition switch to OFF or to use the MUT-II to
I once more before mode I operation can resumed.
However, all
readiness test and frame
data will be erased after returning to mode
so this
should be recorded beforehand if necessary.
(1) Using the scan tool, changeover the diagnostic test mode
of the engine control module to DIAGNOSTIC TEST
MODE II. (INCREASED SENSITIVITY)
(2) Road test the vehicle.
(3) Read the diagnostic trouble code in the same ma nner
as “READ OUT OF DIAGNOSTIC TROUBLE CODE” and
repair the malfunctioning part.
(4) Turn off the ignition
NOTE
Turning OFF the ignition switch will cause the engi ne
control module to changeover the ECM from the diagn ostic
test mode II to the diagnostic test
Revision

ENGINE
A N D E N G I N E > .
FAIL-SAFE/BACKUP FUNCTION TABLE
When the main sensor malfunctions are by the diagnostic test mode, the vehicle is controlled
by means of the following defaults.
Malfunctioning item Control contents during malfunct ion
Volume air flow sensor
1. Uses the throttle position sensor signal and eng ine speed signal (crankshaft position
sensor signal) for basic injector drive timing and basic ignition timing from the
2. motor in the appointed position so idle air contro l is not performed.
Intake air temperature
Controls as if the intake air temperature is
sensor
Throttle position
sensor (TPS)
Engine coolant
temperaturesensor
Camshaft position
sensor
Barometric pressure
sensor
Knock sensor
Engine (Turbo)>
Ignition coil, power
transistor unit
Heated oxygen sensor
Heated oxygen sensor
Misfire detection
Turbocharger waste
gate actuator Engine
terminal Performs the closed loop control of the air/fuel ra
tio by using only the signal of the heated
oxygen sensor (front) installed on the front side o f the catalytic converter.
The ECM stops supplying fuel to the cylinder with t he highest misfiring rate if a misfiring that
could damage the catalytic converter is detected.
Shuts off fuel in case of overcharge.
Does not restrict the generator output with respect to electrical load.
No increase in fuel amount during acceleration due to the unreliable throttle position
sensor signal.
Controls as if the ‘engine coolant temperature is
fuel into the cylinders in the order with irregular timing.
(After the ignition switch is turned to ON, the No. 1 cylinder top dead center is not de-
tected at all.)
off the fuel supply 4 seconds after a problem is d etected.
(After the ignition switch is turned to ON, the No. 1 cylinder top dead center is not de-
tected at all.)
Controls as if the barometric pressure is 101
(30 (sea level).
Switches the ignition timing from ignition timing f or high octane to ignition timing for standard
octane fuel.
Cuts off the fuel supply to cylinders with an abnor mal ignition signal.
Air/fuel ratio closed loop control is not performed
TSB Revision

ENGINE (TURBO)
AND ENGINE> Troubleshooting
Code No. Volume Air Flow Circuit Malfunction
[Comment]Background
lWhile the engine is running, the volume air flow se nsor outputs a signal which
corresponds to the volume of air flow.
lThe engine control module checks whether the freque ncy of this signal output by the
volume air flow sensor while the engine is running is at or above the set value.
Check Area, Judgement Criteria
1. Check Area
Engine is not lower than 500
Judgement CriterialSensor output frequency has continued to be 3.3 Hz or lower for 4 sec.
2. Check Area l Throttle position sensor voltage is 2
or lower. Engine speed is not higher than 2000
Judgement CriterialSensor freauencv has continued to be 1000 Hz or hiaher fo r 4 sec. EnginelSensor output frequency has continued to be 800 Hz or higher for 4 sec. Engine>
3. Check Area
l Throttle position sensor voltage is 1.5 or higher.
l Engine speed is 2000 or higher.
Judgement CriterialSensor output frequency is Hz or lower for 4 seconds.
Measure at the volume air flow Check the volume air flow sensor
sensor connector A-l 02. circuit. (Refer to
l Connect the connector. (Use PROCEDURE 47.)
the test harness:
1. Voltage between 3 and ground(Engine: idling)OK: 2.2-3.2 2. Voltage between 7 and ground OK: (Engine: idling)
6 - 9
OK
Replace the ECM.
(Ignition switch: ON)
O K : 6 - 9
TSB Revision
Check the following connector
Probable cause
lVolume air, flow lOpen or shorted sensor or loose connector Engine control module failed
Check trouble symptom.
N G
Repair
Replacethevolumeairflowsensor.
, Check trouble
Repair
Replace the ECM.

ENGINE ( T U R B O )
AND ENGINE> Troubleshooting
Code No. Barometric Pressure Malfunction Probable cause ,
[ C o m m e n t ]BackgroundlThe barometric pressure sensor outputs a voltage wh
ich corresponds to the barometricpressure.
Barometric pressure sensor failedlOpen or shorted barometric or loose connectorl Engine control module failedl The engine control module checks whether this volta ge is within a specified range.
Check Area l 60
or more have passed since the starting sequence wa s completed.
l Battery voltage is not lower than 8 V.
Judgement CriterialSensor output voltage has continued to be 4.5 or higher [corresponding to a barometricpressure of 114 (17 psi) or higher] for 4 sec. ,
or
lSensor output voltage has continued to be 1.95 or lower a barometricpressure of 50 (7.4 psi) or lower] for 4 sec.
theECM and the barometric
NGMeasure at the volume air flow
sensor connector
lDisconnect the connector, andmeasure at the harness side.lVoltage between 1 and ground(Ignition switch: ON)
O K :
l Continuity between 5 andground
sor connector l Connect the connector. (Use
the test harness:
lVoltage between 2 and ground(Ignition switch: ON)
OK: 3.7-4.3
[Altitude: 0 (0 ft.)]
[Altitude: 1,200 (3,937
OK
at the ECM 3-56. Connect the connector. Voltage between 85 and ground (Ignition switch: ON)
OK: 3.7-4.3
[Altitude: 0 (0 ft.)]
I
[(Altitude: 1,200 (3,937ii.)]
Continuity
OKsure sensor connector.I
Check the following connector: Repair
A-i
OK
OK
Check trouble symptom.
NG
Replace the ECM.
N GCheck the harness wire between Repairthe ECM and the barometric pres-sure sensor connector.
OKOK
the ECM and the barometric pres- harness wire
sure sensor connector.
Repair
OK
the ECM.
TSB Revision1

ENGINE (TURBO)
AND ENGINE> Troubleshooting,
Code No. Intake Air Temperature Circuit
[Comment]
Background
lThe intake air temperature sensor converts the intake air temperature to a voltage and
outputs it.
l The engine control module checks whether the voltag e is within a specified range.
Check Area
l 60
or more have passed since the starting sequence wa s completed.
Judgement CriterialSensor output voltage has continued to be 4.6 or higher [corresponding to an intake
air temperature of or lower] for 4 sec.
or
lSensor output voltage has continued to be 0.2 or lower [corresponding to an intake
air temperature of or higher] for 4 sec.
l Intake air temperature lOpen or shorted intake circuit, or loose l Engine control
Check the intake air temperature sor. (Refer to Replace the volume air flow sensor.
Measure at the volume air flow sensor
l
l a n d g r o u n d Check the wire between the RepairECM and the intake air temperaturesensor connector.
Replace the ECM.
Revision

ENGINE (TURBO)
AND ENGINE>
Code No. 5 Engine Coolant Temperature Circuit
Malfunction Probable
[Comment]l
Engine coolant temperature BackgroundlOpen shorted engine l theenginecoolanttemperature and outputs it. sensor circuit, or l
The engine control module checks whether the voltag e is within a specified range.l
Engine control module In addition, it checks that the engine coolant temp erature (signal) does not drop while
the engine is warming up.
Check Area, Judgement Criteria
1. Check Area, Judgement Criteria
lSensor output voltage has continued to be 4.6 or higher [corresponding to an enginecoolant temperature of or lower] for 4 sec.
or
lSensor output voltage has continued to be 0.1 or lower [corresponding to an enginecoolant temperature of or higher] for 4 sec.
2. Check Area, Judgement CriterialSensor output voltage increased from a value lower than 1.6 to a value higher than1.6 [Engine coolant temperature decreases from a highe r than temperature to a lower than temperature.]lThen the sensor output voltage has continued to be 1.6 or higher for 5 min.
3. Check Area
lEngine coolant temperature is approximately immediately after engine
is started.
Judgement CriterialAbout 60 300 have passed for the engine coolant temperature to about after starting sequence was completed.
Measure at the engine coolant
temperature sensor connector
l Disconnect the connector, and
measure at the harness side.
l Voltage between 1 and ground
(Ignition switch: ON)
OK:
l Continuity between 2 and ground
OK: Continuity
Check trouble symptom.
NG
Replace the ECM.
Replace the
TSB Revision

ENGINE (TURBO)
AND ENGINE> Troubleshooting
Code No. Throttle Position Circuit MalfunctionProbable cause’
[Comment]lThrottle position sensor failed or Backgroundl lThe throttle position sensor outputs a voltage whic h corresponds to the throttle valve
or loose connector
opening angle.
l The engine control module checks whether the voltag e is within a specified range. InClosed switch l Closed throttle position switch addition, it checks that the voltage output does no t become too large while the engineshortedis at idle. Engine control module failed
Check Area, Judgement Criteria
1. Check Area, Judgement Criteria l
Withtheclose throttle position switch set to ON, the senso r output voltage has continuedto be 2 or higher for 4 sec.orI ,
l Sensor output has continued to be 0.2 or lower for 4 sec.
2. Check Area
l Engine speed is at between 500 and 3000 Volumetric efficiency is 30% or lower.
Judgement Criterial Sensor output voltage has continued to be 4.6 or higher for 4 sec.
3. Check Area
l Engine speed is higher than 2000 l Volumetric efficiency is 60% or higher.
Judgement Criterial Sensor output voltage is or less for 4 seconds.
26 Cosed throttle position switchsystemOK:With the throttle valve at the idleposition: ON
With the throttle valve slightly
ooen: OFF (Refer to
INSPECTION
Check the throttle position sensor. Replace
Measure at the position sensorconnectorl
Disconnect the connector, and
measure at the harness side.
l Voltage between
and ground
(Ignition switch: ON)
O K :
l Continuity between 4 and ground
OK: Continuity
TSB Revision
ECM and the throttle position sensor
Check the throttle position sensor Replace the ECM.

ENGINE (TURBO)
AND ENGINE> Troubleshooting
Code No. (Heated Oxygen) Sensor Circuit . .
Malfunction (Bank Sensor 1)
[Comment]lBackgroundHeated oxygen sensor deteriorated , ,l
lWhen the heated oxygen sensor begins to the sensor signal responseOpen circuit in heated oxygen l i n ebecomes poor. l Engine control module failedlThe engine control module forcibly the mixture to make it leaner and richer,and checks the response speed of the heated oxygen sensor.In addition, the engine control module also checks for an open circuit in the heated oxygensensor output line.
Check Area, Judgement Criteria
1. Check Areal Engine coolant temperature sensor: normallHeated oxygen sensor signal voltage has continued t o be 0.1 or lower for 3 minor more after the starting sequence was completed.l Engine coolant temperature is higher than l Engine speed is higher than 1200 l Volumetric efficiency is not lower than 25%.
l intake air temperature is or higher
l Barometric pressure is 76 (11 psi.) or higher.
Judgement CriterialInput voltage supplied to the engine control module interface circuit is not lower than
4.5 when 5 is applied to the heated oxygen sensor output line via a resistor.
2. Check Area l Engine coolant temperature sensor: Normal
l Engine
temperature is not lower than l Engine speed is between 1500 and 3000 lEngine speedis between and 3000 l Volumetric efficiency is 25 60%.
l Intake air temperature is or higher
l Barometric pressure is 76 (11 psi.) or higher.
l Under the closed loop air-fuel control.
l Monitoring time: 6
Judgement CriterialWhen the air-fuel ratio is forcibly changed (lean t o rich and rich to lean), the heated
oxygen sensor signal doesn’t provide response withi n 1.2 sec.
l Monitored only once per
TSB Revision
Check the heated oxygen sensor
(front). (Refer to N G Repair
NGOK
ReplaceCheck trouble symptom.
NGNGCheck the harness wire between the Repair
ECM and the heated sensor (front) connector.. .
OK
Replace the oxygen sensor (front).
I
Check trouble symptom.
NG
Replace the ECM.