
DIAGNOSIS SYSTEM
MULTIPOINT FUEL INJECTION (MPI) <4A9>13A-19
Engine-ECU 
•Items useful for grasping the engine control con-
dition by the engine-ECU 
engine-CVT-ECU 
monitor item section.
•Values of these monitor items vary greatly 
depending on marginal difference of measure
-
ment conditions, difference of the environment, 
aged deterioration of vehicles and so on, and it is 
difficult to show the precise specification values. 
Therefore, check conditi ons, display range and 
movement of values are described.
Item No.Inspection itemDisplay range, numerical value
5AAir-fuel ratio learning value of B zone (Low 
speed load)−25 to 25%
5BIdle speed control position learned value−128 to 127STEP
5CIdle speed control position learned value (A/C 
load)−128 to 127STEP
6AKnock retardRetards in response to accelerator opening
6BLearned knock retard0 − 100%
6CTarget idle speedChanges in response to engine coolant 
temperature
9BAir-fuel ratio learning value of A zone (Low 
load)−25 to 25%
9DAir-fuel ratio feedback integration−25 to 25%
B2Alternator G terminal dutyIncreases
B3Purge control solenoid valve duty0 − 100%
81*Long-term fuel compensation−25 to 25%
82*Short-term fuel compensation−25 to 25%
87*Calculation load value0 − 100%
88*Fuel control conditionChanges depending on driving condition
NOTE: *: This item is not displayed when the data list in check mode is selected. 

GENERAL INFORMATION
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-4
CONTROL SYSTEM DIAGRAM
AK600529AB
6  Oil feeder control valve 
1  Oxygen sensor
(front)
8  Engine coolant 
 temperature sensor
3 
Throttle valve control servo
10  
Throttle position sensor  (main)
5   Throttle position sensor  (sub)
2  Purge control
   solenoid valve
4 Fuel pressure 
solenoid valve
7  Crank angle sensor
9  
Detonation sensor
4  
Intake air 
 temperature
 sensor
3  
Air flow sensor
Waste gate
actuator Canister
Check 
valve Air by-pass valve
Fuel pressure regulatorFrom 
fuel pump
To fuel 
tank
Catalytic converter
Catalytic 
converter
Air 
inlet
Oxygen sensor (front)
Oxygen sensor (rear)
Air flow sensor
Intake air temperature 
sensor
Throttle position 
sensor 
(sub)
Camshaft position 
sensor
Crank angle sensor
Engine coolant 
temperature sensor
Detonation sensor
Throttle position 
sensor  (main) Power supply
Ignition switch-IG
Ignition switch-ST
Accelerator pedal 
position sensor 
(main)
Accelerator pedal 
position sensor
(sub)
Alternator FR 
terminal
Stop lamp switch
Clutch switchEngine-
ECUEngine control relay
Fuel pump relay 
A/C compressor relay
Throttle valve
control servo relay
Ignition coil
Cooling fan 
control relay
(Hi, Lo)
Diagnosis output
Alternator G terminal
Oxygen sensor (front)
heater
Oxygen sensor (rear)
heater
Barometric
pressure
sensor
1 Injector
5  Waste gate
    solenoid valve
2   Oxygen sensor
(rear)
6   Camshaft position sensor
1
2
3
4
5
6
7
8
9
10 Injector
Purge control
solenoid valve
Throttle valve
control servo
Fuel pressure
solenoid valve
Waste gate
solenoid valve
Oil feeder control
valve
1
2
3
4
5
6 

DIAGNOSIS SYSTEM
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-16
P0500Vehicle speed sensor systemOpen circuit or short-circuit in 
sensor-related circuitsON
P0513Immobilizer malfunctionOpen circuit or short-circuit in 
sensor-related circuits−
P0603EEPROM malfunctionAbnormality in engine-ECU−
P0606Engine-ECU main processor 
malfunctionAbnormality in engine-ECUON
P0622Alternator FR terminal systemOpen circuit or short-circuit in 
system-related circuits−
P0638Throttle valve control servo circuit 
range/performance problemAbnormal throttle valve control 
servoON
P0642Throttle position sensor power 
supply malfunctionOpen circuit or short-circuit in 
sensor-related circuitsON
P0657Throttle valve control servo relay 
circuit malfunctionOpen circuit or short-circuit in 
sensor-related circuitsON
P1021Oil feeder control valve systemOpen circuit and short-circuit in 
solenoid valve-related circuits−
P1231Trustful check active stability 
control (ASC)ABS/ASC-ECU−
P1233Trustful check throttle position 
sensor (main)Abnormality in throttle position 
sensor (main)ON
P1234Trustful check throttle position 
sensor (sub)Abnormality in throttle position 
sensor (sub)ON
P1235Trustful check air flow sensorAbnormality in air flow sensorON
P1236A/D converter systemAbnormality in engine-ECUON
P1237Trustful check accelerator pedal 
position sensorAbnormality in accelerator pedal 
position sensorON
P1238Air flow sensor trustful for torque 
monitoringAbnormality in engine-ECUON
P1239Trustful check engine speedAbnormality in engine-ECUON
P1240Trustful check ignition angleAbnormality in ABS/ASC-ECU−
P1241Torque monitoringAbnormality in engine-ECUON
P1602Communication malfunction 
(between engine-ECU main 
processor and system LSI)Abnormality in engine-ECUON
P1603Battery back-up circuit malfunctionOpen circuit or short-circuit in 
system-related circuitsON
P2100Throttle valve control servo circuit 
(open)Open circuit in throttle valve control 
servo-related circuitON
P2101Throttle valve control servo 
magneto malfunctionShort-circuit in system-related 
circuitsON
P2108Throttle valve control servo 
processor malfunctionAbnormality in engine-CVT-ECUON
Code No. Diagnosis item Main diagnosis contents Engine 
warning lamp 

DIAGNOSIS SYSTEM
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-18
NOTE: Items marked "*" will not appear if a data list is selected in the check mode.
ACTUATOR TEST FUNCTION
The actuator test items are given in the table below
Item No.Inspection itemDrive contents
01InjectorsCut fuel to No.1 injector
02Cut fuel to No.2 injector
03Cut fuel to No.3 injector
04Cut fuel to No.4 injector
07Fuel pumpFuel pump operates and fuel is recirculated
08Purge control solenoid valveSolenoid valve turns from OFF to ON
12Waste gate solenoid valveSolenoid valve turns from OFF to ON
17Basic ignition timingSet to ignition adjustment mode
20Cooling fan control relay (high speed)Drive the fan motor at high speed
21Cooling fan control relay (low speed)Drive the fan motor at low speed
34Throttle valve control servoStop the throttle valve control servo
12*Air flow sensorgm/s
13*Intake air temperature sensor°C
21*Engine coolant temperature sensor°C
22*Crank angle sensorr/min
24*Vehicle speedkm/h
44*Ignition advancedeg
8A*Throttle position sensor (main)%
A1*Oxygen sensorV
Item No. Inspection item Unit 

DIAGNOSIS SYSTEM
MULTIPOINT FUEL INJECTION (MPI) <4G1>13B-19
Engine-ECU Monitor Item
•Items useful for grasping the engine control condition by the engine-ECU are provided in this monitor item 
section.
•Values of these monitor items vary greatly depending  on marginal difference of measurement conditions, 
difference of the environment, aged deterioration of vehicl es and so on, and it is difficult to show the pre
-
cise specification values. Therefore, check conditions, display range and movement of values are 
described.
Item No.Inspection itemDisplay range, numerical value
5AAir-fuel ratio learning value of B zone (Low 
speed load)−25 to 25%
5BIdle speed control position learned value−128 to 127STEP
5CIdle speed control position learned value (A/C 
load)−128 to 127STEP
6AKnock retardRetards in response to accelerator opening
6BLearned knock retard0 − 100%
6CTarget Idle speedChanges in response to engine coolant 
temperature
9BAir-fuel ratio learning value of A zone (Low 
speed load)−25 to 25%
9DAir-fuel ratio feedback integration−25 to 25%
B1Waste gate solenoid valve duty0 − 100%
B2Alternator G terminal dutyIncreases
B3Purge control solenoid valve duty0 − 100%
81*Long-term fuel compensation−25 to 25%
82*Short-term fuel compensation−25 to 25%
87*Calculation load value0 − 100%
88*Fuel control conditionChanges depending on driving condition
NOTE: *: This item is not displayed when the data list in check mode is selected. 

DIAGNOSTIC FUNCTION
SMART WIRING SYSTEM (SWS)54B-8
DIAGNOSTIC FUNCTION
M2541003000642
DIAGNOSIS CODE SET
For more information about diagnosis code output, 
refer to the Workshop Manual.
SWS INPUT SIGNAL CHECK USING 
M.U.T.-III
When the M.U.T.-III is connected to the diagnosis 
connector and any of the SWS-linked switches is 
operated, the PC buzzer sounds to evaluate whether 
the switch is normal or not.
SWS INPUT SIGNAL CHECK AND ECU 
CHECK BY USING SWS MONITOR
The switch signals sent by ECUs and the operations 
of these ECUs can be confirmed by using the SWS 
monitor and the M.U.T.-III.
INPUT SIGNALS THAT CAN BE CHECKED
Input signalCondition for sounding buzzerDisplay on 
M.U.T.-III (when 
SWS monitor is 
used)
Ignition switch (ACC)Turn from "LOCK" (OFF) to "ACC" positionfrom OFF to ON
Ignition switch (IG1)Turn from "ACC" to "ON" positionfrom OFF to ON
Key reminder switchRemove the ignition key from ignition key cylinder 
(form inserted position)from OFF to ON
Hazard lamp switchTurn from OFF to ONfrom OFF to ON
Fog lamp switch
Remote controlled mirror 
switch (unfolding/folding 
switch)
Speed signal When the speed changes from less than 10 km/h to 
more than 10 km/hDisplays the 
vehicle speed
Cranking signalWhile the ignition switch is in START position (while 
cranking the engine)−
Selector lever P position signal 
(parking)When the selector lever is shifted to the "P" position 
(Ignition switch: ON or START)−
Selector lever R position signal 
(reverse)When the selector lever is shifted to the "R" position 
(Ignition switch: ON or START)−
Buzzer triggered by 
ETACS-ECU
*1
When the following conditions are satisfied
•Ignition switch: LOCK (OFF) position
•Lighting switch: ON
•Driver’s door switch: ON (Driver’s door: OPEN)
ON
When requirements for sounding each warning buzzer 
are not satisfiedOFF
Door switchDriver’s doorWhen door(s) or tailgate is opened from the closed 
positionfrom OFF to ON
Passenger’s 
door
Rear door
All door switchA door is opened when all the doors are closedfrom OFF to ON 

CONSTRUCTION DIAGRAM
ACTIVE STABILITY CONTROL SYSTEM (ASC)35C-8
EXAMPLE OF THE EFFECT OF CONTROL
AC204504
AC204505
AC204506AC204507AB
Restraining under-steering Restraining over-steering
Avoiding under-steering Avoiding wheel spin
Improving ABS performance
Stable vehicle attitude
after avoiding obstacles
Example of TCL control
When th e driving  wheel  slip s (ex. during drivin g on 
low 
µ road), TCL  send s the  engine out put red u ction 
sign
al to  the en gine  ECU in order  to prevent th e driv
-
ing f o r c e  loss cau s e d   by t he  dr iving  whe e l slip . A t  t h e  
same time, TCL a
pplies th e brake to t he slipp i ng 
driving whe
e l so that  the drivin g force is applied  to 
t
he non-slipping  driving wheel, which  co ntrols the  slip 
o
f  th e drivi ng wheel,  securin g  the  prop er d r iving f o rce 
and increa
sed steering fo rce.
Fail-safe and diagnostic functions
ASC-ECU constantly mo nitors the input  and ou tput 
sign
als. If an  error is det ected  in th e syste m , 
ASC-ECU send
s a f a il  sign al a nd the  correspond ing 
indicato
r lamp is illuminate d  or blinks. V a riou s con
-
trols are proc essed  depen ding  on the  cause of  mal-
functi on a s  shown below . ASC-ECU has the 
follo
wing fu nctions  for  easier system checks.
•Diagnosis code set
•Service  dat a outp u t
•Actuator te st
All the above it ems can  be diagnosed using  
M.U.T
. -III. 

CONSTRUCTION DIAGRAM
ACTIVE STABILITY CONTROL SYSTEM (ASC)35C-11
C1371Yaw rate sensor signal 
errorEnabledEnabledProhibitedProhibitedProhibitedProhibited
C1385Yaw rate sensor error
C1387Lateral G-sensor errorEnabledEnabledProhibitedProhibitedProhibitedProhibited
C1388Yaw rate sensor active 
check errorEnabledEnabledProhibitedProhibitedProhibitedEnabled
C1394Steering wheel sensor 
neutral point not learnedEnabledEnabledProhibitedProhibitedProhibitedProhibited
C1396Engine torque 
intervention rejectionEnabledEnabledProhibitedProhibitedProhibitedProhibited
C1505Steering wheel sensor 
malfunction (detection at 
the ASC-ECU side)EnabledEnabledProhibitedProhibitedProhibitedProhibited
C1555Range exceeding of 
steering wheel sensor
C1607Malfunction of ASC-ECUProhibitedProhibitedProhibitedProhibitedProhibitedProhibited
ASC-ECU malfunction 
(CAN communication 
circuit failure)EnabledEnabledProhibitedProhibitedProhibitedProhibited
C1621G and yaw rate sensor 
improper installationEnabledEnabledProhibitedProhibitedProhibitedProhibited
C1860Abnormal rise of 
ASC-ECU power supply 
voltageProhibitedProhibitedProhibitedProhibitedProhibitedProhibited
C1861Abnormal drop of 
ASC-ECU power supply 
voltageProhibitedEnabledProhibitedProhibitedProhibitedProhibited
C1862Abnormal power supply 
voltage of G and yaw rate 
sensor (high voltage)EnabledEnabledProhibitedProhibitedProhibitedProhibited
C1863Abnormal power supply 
voltage of G and yaw rate 
sensor (low voltage)
U1073Bus-offEnabledEnabledProhibitedProhibitedProhibitedProhibited
U1100Engine-related CAN 
time-out errorEnabledEnabledProhibitedProhibitedProhibitedProhibited
U1104Steering wheel sensor 
CAN time-out errorEnabledEnabledProhibitedProhibitedProhibitedProhibited
U1105G and yaw rate sensor 
CAN time-out errorEnabledEnabledProhibitedProhibitedProhibitedProhibited
U1406Accelerator pedal position 
signal errorEnabledEnabledProhibitedProhibitedProhibitedProhibited
U1426Engine speed signal errorEnabledEnabledProhibitedProhibitedProhibitedProhibited
U1427Engine torque signal errorEnabledEnabledProhibitedProhibitedProhibitedProhibited
Diagnosis 
code No.Item ABS EBD TCL ASC
Engine 
controlBrake 
controlEngine 
controlBrake 
control