Page 585 of 1449

MPI -Troubleshooting
Fig. 1
Vehicle
speedInitial ac-
celerator
pedal de-
pressionNormalHesitation
Sag
TimeFig. 2
Normal
Initial ac-
celerator
pedal de-
pression
IdlingStumble
Time Vehicle
speed
13A-53
PROBLEM SYMPTOMS TABLE (FOR YOUR INFORMATION)
ItemsSymptom
StartingWon’t startThe starter is used to crank the engine, but there is no combustion within the
cylinders, and the engine won’t start.
Fires up and diesThere is combustion within the cylinders, but then the engine soon stalls.
Hard startingEngine starts after cranking a while.
Idling
stability
HuntingEngine speed doesn’t remain constant; changes at idle.
stability
Rough idleUsually, a judgement can be based upon the movement of the tachometer
pointer, and the vibration transmitted to the steering wheel, shift lever, body, etc.
This is called rough idle.
Incorrect idle speedThe engine doesn’t idle at the usual correct speed.
Engine stall
(Die out)The engine stalls when the foot is taken from the accelerator pedal, regardless
of whether the vehicles is moving or not.
Engine stall
(Pass out)The engine stalls when the accelerator pedal is depressed or while it is being
used.
DrivingHesitation Sag“Hesitation” is the delay in response of the vehicle speed (engine speed) that
occurs when the accelerator is depressed in order to accelerate from the speed
at which the vehicle is now traveling, or a temporary drop in vehicle speed
(engine speed) during such acceleration.
Serious hesitation is called “sag”. (Refer to Fig. 1)
Poor accelerationPoor acceleration is inability to obtain an acceleration corresponding to the
degree of throttle opening, even though acceleration is smooth, or the inability
to reach maximum speed.
StumbleEngine speed increase is delayed when the accelerator pedal is initially
depressed for acceleration. (Refer to Fig. 2)
ShockThe feeling of a comparatively large impact or vibration when the engine is
accelerated or decelerated.
SurgeThis is repeated surging ahead during constant speed travel or during variable
speed travel.
KnockingA sharp sound like a hammer striking the cylinder walls during driving and which
adversely affects driving.
StoppingRun on
(“Dieseling”)The condition in which the engine continues to run after the ignition switch is
turned to “LOCK” (OFF) position. Also called “Dieseling”.
Page 586 of 1449

MPI -Troubleshooting13A-54
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
Communication between MUT-IIand entire system is not
possible.
Probable cause
Causes shown on right are suspected.DDiagnosis connector malfunction
DMUT-IImalfunction
Check and repair the harness between
the diagnosis connector and body
earth.
DCheck for damage of the earth
cable.
OK
OK
Check the harness between the
diagnosis connector and battery.
DCheck for damage of the power
cable.NG
Repair
NG
Check the following connectors:
C-213, C-211, C-132, C-35
drive vehicles>NG
Repair
Check the trouble symptoms.OK
End
OK
Replace the MUT-II.
OK
Check and repair the harness between
the diagnosis connector and battery.
DCheck for disconnection and
short - circuit of the power cable.
(2) NGCheck the following connectors:
C-213, C-211, C-132, C-35
drive vehicles>NG
Repair
Check and repair the harness between
the diagnosis connector and body
earth.
DCheck for disconnection and
damage of the earth cable.
OK
Measure at the C-22 diagnosis
connector.
DDisconnect the connector to
measure at the harness side.
(1) Resistance between terminal No. 4
and earth
Resistance between terminal No. 5
and earth
OK:2Ωor less
(2) Voltage between terminal No. 16
and earth
OK:System voltage(1) NG
Check the following connector:
C-22NG
Repair
Page 587 of 1449

MPI -Troubleshooting13A-55
Inspection Procedure 2
Only communication between MUT-IIand engine-ECU is
not possible.
Probable cause
Causes shown on right are suspected.DIgnition switch malfunction
DEngine control relay malfunction
DEngine-ECU malfunction
NG
Replace the engine-ECU.
OK
Check the trouble symptoms.OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
OK
Check the harness between the
diagnosis connector and engine-ECU.
DCheck for disconnection,
short-circuit and damage of the
communication cable.
DCheck for disconnection,
short-circuit and damage of the
signal cable.NG
Repair
OK
Check the following connectors:
C-26, C-130, C-118, C-108, C-28
, C-102
drive vehicles>, C-145
MMCS>NG
Repair
Check the engine warning lamp.
DIgnition switch: ON
OK:Engine warning lamp is
illuminated.NGCheck the Inspection Procedure 22:
Engine-ECU power supply, engine
control relay, ignition switch-IG system.
NOTE
If the problem symptom does not disappear in the vehicle with MMCS after carrying out the above - mentioned
inspection procedure, there may be a malfunction in the multi - center display.
Page 588 of 1449

MPI -Troubleshooting13A-56
Inspection Procedure 3
Engine warning lamp does not illuminate immediately
after ignition switch is set to ON position.
Probable cause
The engine-ECU illuminates the engine warning lamp for 5 seconds immediately after
ignition switch is set to “ON” position to check whether the engine warning lamp bulb
is dead.DEngine warning lamp bulb dead
DIgnition switch malfunction
DEngine control relay malfunction
DEngine-ECU malfunction
NG
Replace the engine-ECU.
OK
Check the trouble symptoms.OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note for Intermittent
Malfunctions.)
OK
Check the harness between the combination meter and engine-
ECU.
DCheck for damage of the output cable.NG
Repair
OK
Check the following connector:C-130NG
Repair
OK
Check the harness between the combination meter and ignition
switch.
DCheck for damage of the power cable.NG
Repair
OK
Check the following connectors:C-213, C-210, C-201NG
Repair
OK
Check and repair the harness between
the combination meter and engine-
ECU.
DCheck for disconnection and
short-circuit of the output cable.
OK
Measure at the C-122 engine-ECU
connector.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ON
DVoltage between terminal No. 36
and earth
OK:System voltageNGCheck the following connector:
C-130NG
Repair
OK
Check the following connector:
C-122NG
Repair
OK
Check and repair the harness between
the combination meter and ignition
switch.
DCheck for disconnection and
short-circuit of the power cable.
OK
Measure at the C-01 combination
meter connector.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ON
DVoltage between terminal No. 9 and
earth
OK:System voltageNGCheck the following connectors:
C-213, C-210, C-201NG
Repair
OK
Check the following connector:
C-01NG
Repair
YES
Check whether engine warning lamp bulb is dead.
(Refer to GROUP 54 - Combination Meter.)NGReplace the engine warning lamp.
Can engine be started?NOCheck the Inspection Procedure 22: Engine-ECU power supply,
engine control relay, ignition switch-IG system.
(Refer to P.13A-82.)
Page 589 of 1449
MPI -Troubleshooting13A-57
Inspection Procedure 4
Engine warning lamp stays illuminated and does not turn
OFF.
Probable cause
The engine-ECU illuminates the engine warning lamp when the occurrence of a
diagnosis code is recorded.DEngine-ECU malfunction
OK
Check and repair the harness between
the combination meter and engine-
ECU.
DCheck for short-circuit of the output
cable.
NG
Check the following connector:
C-130NG
Repair
NG
Replace the engine-ECU.
OK
Measure at the C-122 Engine-ECU
connector.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ON
DVoltage between terminal No. 36
and earth.
OK:System voltageOKCheck the trouble symptoms.OKIntermittent malfunction
(Refer to GROUP 00 - Points to Note
for Intermittent Malfunctions.)
NO
Check the following connector:
C-122NG
Repair
MUT-IISelf-Diag code
DIs a diagnosis code output?YESINSPECTION CHART FOR DIAGNO-
SIS CODE
(Refer to P.13A-12.)
Page 590 of 1449

MPI -Troubleshooting13A-58
Inspection Procedure 5
Starting disabled (Starter does not rotate.)
Probable cause
Causes shown on right are suspected.DBattery malfunction
DIgnition switch malfunction
DStarter malfunction
NG
Repair
OK
OK
NG
Repair
NG
OK
Check the harness between the igni-
tion switch and engine-ECU.
DCheck for disconnection,
short-circuit and damage of the
output cable.OK
Replace the ignition switch.
OK
Check the ignition switch.
(Refer to GROUP 54 - Ignition Switch.)
MUT-IIData list
DNo. 18: Cranking signal
DIgnition switch: ST
OK:ON
DIgnition switch: ON
OK:OFFNGNG
Repair
Check the battery.
(Refer to GROUP 54 - Battery.)NGReplace the battery.
Check the following connector:
C-201
OK
OK
Repair NG OK
Check the following connector:
B-19
OK
Check and repair the harness between
the ignition switch and starter.
DCheck for disconnection of the
output cable.
Measure at the B-19 starter connector.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ST
DVoltage between terminal No. 1 and
earth
OK:System voltageNG
Repair
Check the following connectors:
C-129, C-115
Check the following connector:
B-14
Check and repair the harness between
the ignition switch and starter.
DCheck for short-circuit of the output
cable.
NG
Repair
OK
Check the following connectors:
B-14, B-19
OK
NG
RepairCheck the following connector:
B-18NG
OK
Measure at the B-18 starter connector.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ST
DVoltage between terminal No. 1 and
earth
OK:System voltageNGCheck and repair the harness between
the battery and starter.
DCheck for disconnection and
short-circuit of the power cable.
NG
RepairOK
Replace the starter.
Check the harness between the bat-
tery and starter.
DCheck for damage of the power
cable.NG
RepairCheck the harness between the ignition
switch and starter.
DCheck for damage of the output
cable.OK
Page 591 of 1449

MPI -Troubleshooting13A-59
Inspection Procedure 6
Starting disabled (Starter rotates but initial combustion
does not occur.)
Probable cause
Causes shown on right are suspected.DBattery malfunction
DIgnition switch malfunction
DIgnition system malfunction
DFuel system malfunction
DThrottle valve malfunction
DTiming belt malfunction
DEngine-ECU malfunction-
OK
To the next page
OK
Check and repair the harness between
the ignition switch and ignition coil for
each cylinder.
DCheck for disconnection and
short-circuit of the power cable.
OK
Measure at the B-114 and B-119
ignition coil connectors.
DDisconnect the connector to
measure at the harness side.
DIgnition switch: ON
DVoltage between terminal No. 1 and
earth
OK:System voltageNGCheck the following connectors:
B-123, B-119NG
Repair
OK
Check the following connectors:
B-114, B-119NG
Repair
OK
MUT-IIData list
DNo. 22: Crank angle sensor (Refer to P.13A-103.)NGCheck the Code No. P0335: Crank angle sensor system.
(Refer to P.13A-35.)
OK
Check and repair the harness between the ignition switch inter-
mediate connector and engine-ECU.
DCheck for disconnection of the output cable.
YES
MUT-IIData list
DNo. 18: Cranking signal
DIgnition switch: ST
OK:ON
DIgnition switch: ON
OK:OFFNGCheck the following
connector:C-42NG
Repair
YES
Does the camshaft rotate during engine cranking?NOCheck the timing belt for defects.
NO
MUT-IIActuator test
DNo. 7: Fuel pump relay
OK:Fuel pump operation sound is heard.NOCheck the Inspection Procedure 23: Fuel pump system.
(Refer to P.13A-85.)
OK
MUT-IISelf-Diag code
DIs a diagnosis code output?YESINSPECTION CHART FOR DIAGNOSIS CODE
(Refer to P.13A-12.)
OK
Check the engine warning lamp.
DIgnition switch: ON
OK:Engine warning lamp is illuminated.NGCheck the Inspection Procedure 22: Engine-ECU power supply,
engine control relay, ignition switch-IG1 system.
(Refer to P.13A-82.)
Check the battery. (Refer to GROUP 54 - Battery.)NGReplace the battery.
Page 592 of 1449
MPI -Troubleshooting13A-60
NG
Check for the entry of foreign matter (water, kerosene, etc.) in fuel.
Check the trouble symptoms.OK
End
NG
Replace the engine-ECU.
OK
Check the trouble symptoms.OK
End
OK
Check the harness between the ignition switch and ignition coil for
each cylinder.
DCheck for damage of the power cable.NG
Repair
OK
Check the ignition coil parts.
(Refer to GROUP 16 - Ignition Device.)NGReplace the ignition coil.
OK
Check the spark plug. (Refer to GROUP 16 - Ignition Device.)NGReplace the spark plug.
OK
Check the spark plug cable.
(Refer to GROUP 16 - Ignition Device.)NGReplace the spark plug cable.
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