CVT-20
< SERVICE INFORMATION >
CVT SYSTEM
Hydraulic Control System
INFOID:0000000001703438
TCM FunctionINFOID:0000000001703439
The function of the TCM is to:
• Receive input signals sent from various switches and sensors.
• Determine required line pressure, shifting point, and lock-up operation.
• Send required output signals to the step motor and the respective solenoids.
CONTROL SYSTEM OUTLINE
The CVT senses vehicle operating conditions through various sensors. It always controls the optimum shift
position and reduces shifting and lock-up shocks.
SCIA1807E
SENSORS (or SIGNAL)
⇒TCM
⇒ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Engine speed signal
CVT fluid temperature sensor
Vehicle speed signal
Overdrive control signal
Stop lamp switch signal
Primary speed sensor
Secondary speed sensor
Primary pressure sensor
Secondary pressure sensorShift control
Line pressure control
Primary pressure control
Secondary pressure control
Lock-up control
Engine brake control
Vehicle speed control
Fail-safe control
Self-diagnosis
CONSULT-III communication
line
Duet-EA control
CAN system
On board diagnosisSte p m ot or
Torque converter clutch solenoid
valve
Lock-up select solenoid valve
Line pressure solenoid valve
Secondary pressure solenoid
valve
Shift position indicator
O/D OFF indicator lamp
Starter relay
CVT-22
< SERVICE INFORMATION >
CVT SYSTEM
Input/Output Signal of TCM
INFOID:0000000001703441
*1: Input by CAN communications.
*2: Output by CAN communications.
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
Line Pressure and Secondary Pressure ControlINFOID:0000000001703442
• When an input torque signal equivalent to the engine drive force is sent from the ECM to the TCM, the TCM
controls the line pressure solenoid valve and secondary pressure solenoid valve.
• This line pressure solenoid controls the pressure regulator valve as the signal pressure and adjusts the pres-
sure of the operating oil discharged from the oil pump to the line pressure most appropriate to the driving
state. Secondary pressure is controlled by decreasing line pressure.
NORMAL CONTROL
Control itemFluid
pressure
controlSelect con-
trolShift controlLock-up
controlCAN com-
munication
controlFail-safe
function
(*3)
InputPNP switch XXXXXX
Accelerator pedal position signal
(*1)XXXXXX
Closed throttle position signal
(*1)X XXX
Engine speed signal
(*1)XX XXX
CVT fluid temperature sensor X X X X X
Stop lamp switch signal
(*1)X XXX
Overdrive control signal
(*1)XX
Primary speed sensor X X X X X
Secondary speed sensor X X X X X X
Primary pressure sensor X X
Secondary pressure sensor X X X
TCM power supply voltage signal X X X X X X
Out-
putStep motor X X
TCC solenoid valve X X X
Lock-up select solenoid valve X X X
Line pressure solenoid valve X X X X
Secondary pressure solenoid valve X X X
O/D OFF indicator signal
(*2)XX
SCIA1846E
CVT-26
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ON BOARD DIAGNOSTIC (OBD) SYSTEM
IntroductionINFOID:0000000001703446
The CVT system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp) and is stored as a DTC in
the ECM memory, and the TCM memory.
The second is the TCM original self-diagnosis performed by the TCM. The malfunction is stored in the TCM
memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail, refer to CVT-47,
"CONSULT-III Function (TRANSMISSION)".
OBD-II Function for CVT SystemINFOID:0000000001703447
The ECM provides emission-related on board diagnostic (OBD-II) functions for the CVT system. One function
is to receive a signal from the TCM used with OBD-related parts of the CVT system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indicator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to CVT system parts.
One or Two Trip Detection Logic of OBD-IIINFOID:0000000001703448
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — 1st trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd trip
The “trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)INFOID:0000000001703449
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( with CONSULT-III or GST) CONSULT-III or GST (Generic Scan Tool) Examples: P0705, P0720 etc.
These DTC are prescribed by SAE J2012.
(CONSULT-III also displays the malfunctioning component or system.)
•1st trip DTC No. is the same as DTC No.
•Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring or
occurred in the past and returned to normal.
CONSULT-III can identify them as shown below, therefore, CONSULT-III (if available) is recom-
mended.
DTC or 1st trip DTC of a malfunction is displayed in SELF-DIAGNOSTIC RESULTS mode for “ENGINE” with
CONSULT-III. Time data indicates how many times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be “0”.
If a 1st trip DTC is stored in the ECM, the time data will be “1t”.
Freeze Frame Data and 1st Trip Freeze Frame Data
ON BOARD DIAGNOSTIC (OBD) SYSTEM
CVT-27
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The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-III
or GST. The 1st trip freeze frame data can only be displayed on the CONSULT-III screen, not on the GST. For
details, refer to EC-109, "
CONSULT-II Function (ENGINE)".
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data, and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
Both 1st trip freeze frame data and freeze frame data (along with the DTC) are cleared when the ECM mem-
ory is erased.
HOW TO ERASE DTC
The diagnostic trouble code can be erased by CONSULT-III, GST or ECM DIAGNOSTIC TEST MODE as
described following.
•If the battery cable is disconnected, the diagnostic trouble code will be lost within 24 hours.
•When you erase the DTC, using CONSULT-III or GST is easier and quicker than switching the mode
selector on the ECM.
The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to EC-47, "
Emission-related Diagnostic Information".
•Diagnostic trouble codes (DTC)
•1st trip diagnostic trouble codes (1st trip DTC)
•Freeze frame data
•1st trip freeze frame data
•System readiness test (SRT) codes
•Test values
HOW TO ERASE DTC (WITH CONSULT-III)
•If a DTC is displayed for both ECM and TCM, it is necessary to be erased for both ECM and TCM.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Turn CONSULT-III ON and touch “TRANSMISSION”.
3. Touch “SELF-DIAG RESULTS”.
4. Touch “ERASE”. (The DTC in the TCM will be erased.) Then touch “BACK” twice.
5. Touch “ENGINE”.
6. Touch “SELF-DIAG RESULTS”.
7. Touch “ERASE”. (The DTC in the ECM will be erased.)
HOW TO ERASE DTC (WITH GST)
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Select Mode 4 with GST (Generic Scan Tool). For details, refer to EC-119, "
Generic Scan Tool (GST)
Function".
Malfunction Indicator Lamp (MIL)INFOID:0000000001703450
DESCRIPTION
Priority Items
1
Freeze frame dataMisfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes CVT related items)
3 1st trip freeze frame data
CVT-32
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Diagnostic Worksheet Chart
Customer name MR/MS Model & Year VIN
Trans. Model Engine Mileage
malfunction Date Manuf. Date In Service Date
Frequency❏ Continuous❏ Intermittent ( times a day)
Symptoms❏ Vehicle does not move. (❏ Any position❏ Particular position)
❏ No shift
❏ Lock-up malfunction
❏ Shift shock or slip (❏ N → D❏ N → R❏ Lock-up❏ Any drive position)
❏ Noise or vibration
❏ No pattern select
❏ Others
()
Malfunction indicator lamp (MIL)❏ Continuously lit❏ Not lit
1❏ Read the item on cautions concerning fail-safe and understand the customer's complaint.CVT-29
2❏ CVT fluid inspection
CVT-36❏ Leak (Repair leak location.)
❏ Sta te
❏ Amount
3❏ Stall test and line pressure test
CVT-36
,
CVT-36
❏ Stall test
❏ Torque converter one-way clutch
❏ Reverse brake
❏ Forward clutch
❏ Steel belt❏ Engine
❏ Line pressure low
❏ Primary pulley
❏ Secondary pulley
❏ Line pressure inspection - Suspected part:
TROUBLE DIAGNOSIS
CVT-33
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4❏ Perform road test.CVT-40
4-1.Check before engine is started CVT-41
❏CVT-151, "O/D OFF Indicator Lamp Does Not Come On"
❏ Perform self-diagnosis. Enter checks for detected items. CVT-47
❏CVT-56
❏CVT-60
❏CVT-63
❏CVT-65
❏CVT-71
❏CVT-76
❏CVT-80
❏CVT-85
❏CVT-87
❏CVT-88
❏CVT-93
❏CVT-95
❏CVT-100
❏CVT-102
❏CVT-104
❏CVT-109
❏CVT-113
❏CVT-115
❏CVT-119
❏CVT-121
❏CVT-125
❏CVT-127
❏CVT-129
❏CVT-131
❏CVT-132
❏CVT-137
❏CVT-141
4-2.Check at idleCVT-41
❏CVT-153, "Engine Cannot Be Started in "P" and "N" Position"
❏CVT-153, "In "P" Position, Vehicle Moves Forward or Backward When Pushed"
❏CVT-154, "In "N" Position, Vehicle Moves"
❏CVT-154, "Large Shock "N" → "R" Position"
❏CVT-155, "Vehicle Does Not Creep Backward in "R" Position"
❏CVT-156, "Vehicle Does Not Creep Forward in "D" or "L" Position"
TROUBLE DIAGNOSIS
CVT-35
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CVT Electrical Parts LocationINFOID:0000000001703454
1. O/D OFF indicator lamp 2. Shift position indicator 3. Accelerator pedal position sensor
4. CVT unit harness connector 5. Fuel door release 6. TCM
7. Overdrive control switch
BCIA0033E
TROUBLE DIAGNOSIS
CVT-37
< SERVICE INFORMATION >
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• Inspect for fluid leakage and check the fluid level. Refer to MA-19, "Checking CVT Fluid" .
Fluid Condition Check
Inspect the fluid condition.
STALL TEST
Stall Test Procedure
1. Inspect the amount of engine oil. Replenish the engine oil if necessary.
2. Drive for about 10 minutes to warm up the vehicle so that the
CVT fluid temperature is 50 to 80°C (122 to 176°F). Inspect the
amount of CVT fluid. Replenish if necessary.
3. Securely engage the parking brake so that the tires do not turn.
4. Install a tachometer where it can be seen by driver during test.
•It is good practice to mark the point of specified engine
rpm on indicator.
5. Start engine, apply foot brake, and place selector lever in “D”
position.
Fluid status Conceivable cause Required operation
Varnished (viscous
varnish state)Clutch, brake
scorchedReplace the CVT fluid and check the
CVT main unit and the vehicle for
malfunctions (wire harnesses, cool-
er pipes, etc.)
Milky white or
cloudyWater in the fluidReplace the CVT fluid and check for
places where water is getting in.
Large amount of
metal powder mixed
inUnusual wear of
sliding parts within
CVTReplace the CVT fluid and check for
improper operation of the CVT.
SAT638A
SAT647B
SAT513G
SAT775B