
TCM FUNCTION=NCAT0014S03The function of the TCM is to:
IReceive input signals sent from various switches and sensors.
IDetermine required line pressure, shifting point and lock-up operation.
ISend required output signals to the step motor and the respective solenoids.
INPUT/OUTPUT SIGNAL OF TCMNCAT0014S04
Sensors and actuators Function
InputPNP switch Detects select lever position and sends a signal to TCM.
Throttle position sensor Detects throttle valve position and sends a signal to TCM.
Closed throttle position switch Detects throttle valve's fully-closed position and sends a signal to TCM.
Wide open throttle position switchDetects a throttle valve position of greater than 1/2 of full throttle and
sends a signal to TCM.
Engine speed signal From ECM.
CVT fluid temperature sensor Detects transmission fluid temperature and sends a signal to TCM.
CVT fluid pressure sensor Detects transmission fluid pressure and sends a signal to TCM.
Primary speed sensor Detects primary pulley rpm and sends a signal to TCM.
Secondary speed sensor Detects secondary pulley rpm and sends a signal to TCM.
Stop lamp switchSends a signal to the TCM relaying the operation condition of the brake
pedal.
Sport mode switchSends a signal to the TCM relaying the operation condition of the sport
mode switch.
Indicator control unit*1Sends a signal to the TCM operation condition of the manual mode switch
in control device.
ABS control unit Sends a signal to the TCM operation condition of the ABS.
OutputStep motor Regulates pulley position in relation to a signal sent from TCM.
Line pressure solenoid valveRegulates (or decreases) line pressure suited to driving conditions in rela-
tion to a signal sent from TCM.
Torque converter clutch solenoid
valveRegulates (or decreases) lock-up pressure suited to driving conditions in
relation to a signal sent from TCM.
CVT indicator (warning) lamp*2 Shows TCM faults, when CVT control components malfunction.
SPORT indicator lamp*3 Shows the operation condition of the SPORT mode switch. *3
Indicator control unit *1Receives the information of gear position on manual mode from TCM, and
sends a signal to indicator.
*1: Hyper CVT M6 models only
*2: Hyper CVT M6 models
*3: Hyper CVT models
OVERALL SYSTEM
Control System (Cont'd)
AT-14

CVT Fluid CheckNCAT0025FLUID LEAKAGE CHECKNCAT0025S011. Clean area suspected of leaking. Ð for example, mating sur-
face of converter housing and transmission case.
2. Start engine, apply foot brake, place selector lever in ªDº posi-
tion and wait a few minutes.
3. Stop engine.
4. Check for fluid leakage.
FLUID CONDITION CHECKNCAT0025S02
Fluid color Suspected problem
Dark or black with burned odor Wear of frictional material
Milky pink Water contamination Ð Road water
entering through filler tube or breather
Varnished fluid, light to dark brown and
tackyOxidation Ð Over or under filling, Ð
Overheating
FLUID LEVEL CHECKNCAT0025S03Refer to MA section (ªChecking CVT Fluidº, ªCHASSIS AND BODY
MAINTENANCEº).
Stall TestNCAT0026STALL TEST PROCEDURENCAT0026S011. Check CVT fluid and engine oil levels. If necessary, add.
2. Drive vehicle for approx. 10 minutes or until engine oil and CVT
fluid reach operating temperature.
CVT fluid operating temperature:
50 - 80ÉC (122 - 176ÉF)
SAT767B
SAT288G Fluid leakage
SAT638A
SAT647B
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
CVT Fluid Check
AT-34

Wiring Diagram Ð AT Ð FTSNCAT0200
YAT203
CONTROL VALVE
(CVT FLUID
TEMPERATURE
SENSOR)
: Detectable line for DTC
: Non-detectable line for DTC
TCM
(TRANSMISSION
CONTROL MODULE)ECM
DTC P0710 CVT FLUID TEMPERATURE SENSOR CIRCUIT
Wiring Diagram Ð AT Ð FTS
AT-56

Wiring Diagram Ð AT Ð FPSNCAT0233
YAT209
TCM
(TRANSMISSION
CONTROL MODULE): Detectable line for DTC
: Non-detectable line for DTC CONTROL VALVE
(CVT FLUID
PRESSURE
SENSOR)ECM
DTC P1791 CVT FLUID PRESSURE SENSOR
Wiring Diagram Ð AT Ð FPS
AT-96

DescriptionNLEC1748The specification (SP) value indicates the tolerance of the value that is displayed in ªDATA MONITOR (SPEC)º
mode of CONSULT-II during normal operation of the Engine Control System. When the value in ªDATA MONI-
TOR (SPEC)º mode is within the SP value, the Engine Control System is confirmed OK. When the value in
ªDATA MONITOR (SPEC)º mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
IB/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
IA/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
IMAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionNLEC1749IVehicle driven distance: More than 5,000 km (3,107 miles)
IBarometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm2, 14.25 - 15.12 psi)
IAtmospheric temperature: 20 - 30ÉC (68 - 86ÉF)
IEngine coolant temperature: 75 - 95ÉC (167 - 203ÉF)
ITransmission: Warmed-up*1
IElectrical load: Not applied*2
IEngine speed: Idle
*1: For after the engine is warmed up to normal operating temperature, drive vehicle until ªFLUID TEMP SEº
(CVT fluid temperature sensor signal) indicates less than 0.9V.
*2: Rear window defogger switch, air conditioner switch, lighting switch are ªOFFº. Cooling fans are not oper-
ating. Steering wheel is straight ahead.
SEF601Z
Inspection ProcedureNLEC1750NOTE:
Perform ªDATA MONITOR (SPEC)º mode in maximum scale dis-
play.
1. Perform ªBasic Inspectionº, EC-QG-72.
2. Confirm that the testing conditions indicated above are met.
3. Select ªB/FUEL SCHDLº, ªA/F ALPHA-B1º and ªMAS A/F
SE-B1º in ªDATA MONITOR (SPEC)º mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to ªDiagnostic Procedureº, EC-QG-99.
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUEQG16I18DE
Description
EC-98

Idle Air Volume LearningNCEC0541DESCRIPTIONNCEC0541S01ªIdle Air Volume Learningº is an operation to learn the idle air vol-
ume that keeps each engine within the specific range. It must be
performed under any of the following conditions:
IEach time IACV-AAC valve, throttle body or ECM is replaced.
IIdle speed or ignition timing is out of specification.
PRE-CONDITIONINGNCEC0541S04Before performing ªIdle Air Volume Learningº, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
IBattery voltage: More than 12.9V (At idle)
IEngine coolant temperature: 70 - 94ÉC (158 - 201ÉF)
IPNP switch: ON
IElectric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime running light systems, set
lighting switch to the 1st position to light only small lamps.
ICooling fan motor: Not operating
ISteering wheel: Neutral (Straight-ahead position)
IVehicle speed: Stopped
ITransmission : Warmed up
For CVT models with CONSULT-II, drive vehicle until ªFLUID
TEMP SEº in ªDATA MONITORº mode of ªCVTº system indi-
cates less than 0.9V.
For CVT models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.
OPERATION PROCEDURENCEC0541S02With CONSULT-IINCEC0541S02011. Start engine and warm it up to normal operating temperature.
2. Check that all items listed under the topic ªPre-Conditioningº
(previously mentioned) are in good order.
3. Turn ignition switch ªOFFº and wait at least 9 seconds.
4. Start the engine and allow it to idle for at least 28 seconds.
5. Select ªIDLE AIR VOL LEARNº in ªWORK SUPPORTº mode.
6. Touch ªSTARTº and wait 20 seconds.
7. Make sure that ªCMPLTº is displayed on CONSULT-II screen.
If ªINCMPº is displayed, ªIdle Air Volume Learningº will not be
carried out successfully. In this case, find the cause of the
problem by referring to the NOTE below.
8. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed750 50rpm (in ªPº or ªNº position for CVT)
Ignition timing15 2É BTDC
SEF712X
SEF713X
SEF714X
BASIC SERVICE PROCEDURESR20DE
Idle Air Volume Learning
EC-46

DescriptionNLEC1748The specification (SP) value indicates the tolerance of the value that is displayed in ªDATA MONITOR (SPEC)º
mode of CONSULT-II during normal operation of the Engine Control System. When the value in ªDATA MONI-
TOR (SPEC)º mode is within the SP value, the Engine Control System is confirmed OK. When the value in
ªDATA MONITOR (SPEC)º mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
IB/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
IA/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
IMAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionNLEC1749IVehicle driven distance: More than 5,000 km (3,107 miles)
IBarometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm2, 14.25 - 15.12 psi)
IAtmospheric temperature: 20 - 30ÉC (68 - 86ÉF)
IEngine coolant temperature: 75 - 95ÉC (167 - 203ÉF)
ITransmission: Warmed-up*1
IElectrical load: Not applied*2
IEngine speed: Idle
*1: For after the engine is warmed up to normal operating temperature, drive vehicle until ªFLUID TEMP SEº
(CVT fluid temperature sensor signal) indicates less than 0.9V.
*2: Rear window defogger switch, air conditioner switch, lighting switch are ªOFFº. Cooling fans are not oper-
ating. Steering wheel is straight ahead.
SEF601Z
Inspection ProcedureNLEC1750NOTE:
Perform ªDATA MONITOR (SPEC)º mode in maximum scale dis-
play.
1. Perform ªBasic Inspectionº, EC-84.
2. Confirm that the testing conditions indicated above are met.
3. Select ªB/FUEL SCHDLº, ªA/F ALPHA-B1º and ªMAS A/F
SE-B1º in ªDATA MONITOR (SPEC)º mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to ªDiagnostic Procedureº, EC-111.
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUESR20DE
Description
EC-110

8 CHECK IACV-AAC VALVE
Refer to ªComponent Inspectionº, EC-SR-270.
OK or NG
OK©GO TO 9.
NG©Replace IACV-AAC valve.
9 REPLACE IACV-AAC VALVE
1. Replace IACV-AAC valve assembly.
2. Perform ªIdle Air Volume Learningº, EC-46.
Is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©INSPECTION END
INCMP©Follow the construction of ªIdle Air Volume Learningº.
10 CHECK TARGET IDLE SPEED
1. Turn ignition switch ªOFFº.
2. Reconnect all harness connectors and vacuum hoses.
3. Start engine and warm it up to normal operating temperature.
4. Also warm up transmission to normal operating temperature
IFor CVT models with CONSULT-II, drive vehicle until ªFLUID TEMP SEº in ªDATA MONITORº mode of ªCVTº system
indicates less than 0.9V.
IFor CVT models without CONSULT-II and M/T models, drive vehicle for 10 minutes.
5. Stop vehicle with engine running.
6. Check target idle speed.
M/T: 750 50 rpm
A/T: 750 50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 11.
NG©Perform ªIdle Air Volume Learningº, EC-45.
11 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-SR-114.
©INSPECTION END
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Diagnostic Procedure (Cont'd)
EC-269