DESCRIPTION
The new small sized automatic transaxle (A4CF2) is for gasoline 2.0 engine.
The transaxle (A4CF2) is improved on the durability, fuel consumption and efficiency by the new main features as followed.
The new main features
- The hydraulic centrifugal oil pressure balance piston.
- The full line pressure variable control system.
- The long travel damper clutch.
- The disc type return spring.
- The ultra flat torque converter.
GENERAL DESCRIPTION
The TCU check ROM I.D all the time, in order to maintain for best condition and surrounding.
DTC DESCRIPTION
The TCU set this code When the ROM I.D is changed by external force or input non-available data.
The Transaxle Range Switch sends the shift lever position information to the TCM (PCM) using a 12V (battery voltage) signal. When the shift lever is in the D (Drive) position the output signal of Transaxle Range Switch is 12V and in all other positions the voltage is 0V. The TCM (PCM) judges the shift lever position by reading all signals, for the Transaxle Range Switch, simultaneously.
The TCM (PCM) sets this code when the Transaxle Range Switch has no output signal for more than 30 seconds.
Refer to DTC P0707 .
The TCM sets this code when the Transaxle Range Switch outputs multiple signals for more than 30 seconds.
The automatic TRANSAXLE fluid (ATF) temperature sensor is installed in the Valve Body. This sensor uses a thermistor whose resistance changes according to the temperature changes. The TCM supplies a 5V reference voltage to the sensor, and the output voltage of the sensor changes when the ATF temperature varies. The automatic TRANSAXLE fluid (ATF) temperature provides very important data for the TCM's control of the Torque Converter Clutch, and is also used for many other purposes.
This DTC code is set when the ATF temperature output voltage is lower than a value generated by thermistor resistance, in a normal operating range, for approximately 1 second or longer. The TCM regards the ATF temperature as fixed at a value of 80°C (176°F).
Refer to DTC P0711 .
Refer to DTC P0711 .
Refer to DTC P0711 .
This DTC code is set when the ATF temperature output voltage is higher than a value generated by thermistor resistance, in a normal operating range, for an extended period of time. The TCM regards the ATF temperature as fixed at a value of 80°C (176°F).
The input (turbine) speed sensor outputs pulse-signals according to the revolutions of the input shaft of the transmission. The PCM/TCM determines the input shaft speed by counting the frequency of the pulses. This value is mainly used to control the optimum fluid pressure during shifting.
The PCM/TCM sets this code if an output pulse-signal is not detected, from the input speed sensor, when the vehicle is running faster than 19 Mile/h (30 Km/h). The Fail-Safe function will be set by the PCM/TCM if this code is detected.
Refer to DTC P0716 .
Refer to DTC P0716 .
The Output Speed Sensor outputs pulse-signals according to the revolutions of the output shaft of the transmission. The Output Speed Sensor is installed in front of the Transfer Drive Gear to determine the Transfer Drive Gear rpms by counting the frequency of the pulses. This value, together with the throttle position data, is mainly used to decide the optimum gear position.
The TCM sets this code if the calculated value of the pulse-signal is noticeably different from the value calculated, using the Vehicle Speed Sensor output, when the vehicle is running faster than 12mph (20km/h). The TCM will initiate the fail safe function if this code is detected.
The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 1st gear ratio, while the transaxle is engaged in the 1st gear. For example, if the output speed is 1000 rpm and the 1st gear ratio is 2.842, then the input speed is 2,842 rpm.
This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 1st gear ratio, while the transaxle is engaged in 1st gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.
The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 2nd gear ratio, while the transaxle is engaged in the 2nd gear. For example, if the output speed is 1000 rpm and the 2nd gear ratio is 1.529, then the input speed is 1,592 rpm.
This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 2nd gear ratio, while the transaxle is engaged in 2nd gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.
The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 3rd gear ratio, while the transaxle is engaged in the 3rd gear. For example, if the output speed is 1,000 rpm and the 3rd gear ratio is 1.000, then the input speed is 1,000 rpm.
This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 3rd gear ratio, while the transaxle is engaged in 3rd gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.
The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 4th gear ratio, while the transaxle is engaged in the 4th gear. For example, if the output speed is 1,000 rpm and the 4th gear ratio is 0.712, then the input speed is 712 rpm.
This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 4th gear ratio, while the transaxle is engaged in 4th gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.
The PCM/TCM controls the locking and unlocking of the Torque Converter Clutch (or Damper Clutch), to the input shaft of the transmission, by applying hydraulic pressure. The main purpose of T/C clutch control is to save fuel by decreasing the hydraulic load inside the T/C. The PCM/TCM outputs duty pulses to control the Damper Clutch Control Solenoid Valve (DCCSV) and hydraulic pressure is applied to the DC according to the DCC duty ratio value. When the duty ratio is high, high pressure is applied and the Damper Clutch is locked. The normal operating range of the Damper Clutch Control duty ratio value is from 30% (unlocked) to 85% (locked).
The PCM/TCM increases the duty ratio to engage the Damper Clutch by monitoring slip rpms (difference in value between engine speed and turbine speed). To decrease the slip of the Damper Clutch, the PCM/TCM increases the duty ratio by applying more hydraulic pressure. When slip rpm does not drop under some value with 100% duty ratio, the PCM/TCM determines that the Torque Converter Clutch is stuck OFF and sets this code.
Refer to DTC P0741 .
The TCM increases the duty ratio to engage the Damper Clutch by monitoring the slip rpms (difference in value between engine speed and turbine speed). If a very small amount of slip rpm is maintained though the TCM applies 0% duty ratio value, then the TCM determines that the Torque Converter Clutch is stuck ON and sets this code.
Refer to DTC P0741 .
The PCM/TCM checks the Damper Clutch Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected) the PCM/TCM judges that DCCSV circuit is malfunctioning and sets this code.
Variable Faced Solenoid (Linear Solenoid): With the duty control which uses higher frequency (600Hz), instead of the existing PWM type which adapts low frequency (60Hz) to control, spool valve can be controlled precisely.
In PWM control, the amount of oil flow is determined by the duration of "ON" signal among continuously repeated ON/OFF signals.
In VFS, the amount is decided by how widely spool valve open the passage of going through.
The TCM checks the VFS Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected), the TCM judges that the Low and Reverse control solenoid circuit is malfunctioning and sets this code.
The Automatic transmission changes the gear position of the transmission by utilizing a combination of clutches and brakes, which are controlled by solenoid valves. This HIVEC automatic transmission consists of a: LR (Low and Reverse Brake), 2ND (2nd Brake), UD (Under Drive Clutch), OD (Over Drive Clutch).
The PCM/TCM checks the Low and Reverse Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected), the PCM/TCM judges that the Low and Reverse control solenoid circuit is malfunctioning and sets this code.
Refer to DTC P0750 .
The PCM/TCM checks the Under Drive Clutch Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected), the PCM/TCM judges that Under Drive Clutch control solenoid circuit is malfunctioning and sets this code.
Refer to DTC P0750 .
The PCM/TCM checks the 2nd brake drive control signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored, (For example, high voltage is detected when low voltage is expected or low voltage is detected when high voltage is expected) the PCM/TCM judges that 2nd Brake drive control solenoid circuit is malfunctioning and sets this code.
Refer to DTC P0750 .
The PCM/TCM checks the Under Drive Clutch Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected or low voltage is detected when high voltage is expected), the PCM/TCM judges that the OVER DRIVE CLUTCH drive control solenoid circuit is malfunctioning and sets this code.
The TCM monitors suppling voltage to "SOLENOID VALVE".
The gear position is fixed at 3rd gear when input value is higher or lower than specification.
The TCM set this code If an input voltage is higher or lower than specification.
The TCM can either receive data from the Engine Control Module or ABS control module, or it can send data to the ECM and ABSCM by using CAN communication. The CAN communication is one of the vehicle communication methods, which is now widely used to transfer the vehicle data.
The TCM reads data on the CAN-BUS line and checks whether the data is equal to the data which the TCM sent before. If the data is not the same the TCM decides that either the CAN-BUS line or TCM are malfunctioning and sets this code.
Refer to DTC U0001 .
Refer to DTC U0001 .
TCM calculates the best condition using the information from all kinds of sensors. If the solenoid valve receives the information on the oil pressure, the solenoid valve actuates according to the driving signal. All kinds of regulators in the valve body are controlled to change the oil passage and also the line pressure is controlled by TCM.
Identifying PWM Solenoid Valve, Bracket And Connector. Scheme 18
PWM (Pulse Width Modulation) SOLENOID VALVE
Structure and functions
PWM solenoid valve is composed of five solenoid valves and the oil capacity in the solenoid valve is changed by the electric duty value of TCM. The oil pressure of the valve body and the torque converter engages or disengages the damper clutch. The solenoid valves send the operating oil pressure to the clutches and brakes at the each range and also control the strength and weakness of oil pressure to reduce the shock when shifting the range.
Identifying PWM Solenoid Valve Terminals. Scheme 19
VFS valve controls the regulator valve and varies the line pressure from 4.5bar to 10.5bar according to the throttle open angle and the shift range. The holder is installed on the upper side of the case and the filter is installed to the two places on the holder outside to prevent in the strange material from flowing in the VFS.
Identifying Variable Force Solenoid Valve Connector, Holder And Filter. Scheme 20
Scheme 21
PWM solenoid valve is controlled linearly according to the current value.
| Type | 3way & Normal High |
|---|---|
| Input voltage | 12V |
| Coil resistance | 3.5±0.2ohms (at 25°C, 77°F) |
| Operating current | 0 ~ 1200 mA |
VOLTAGE AND RESISTANCE SPECIFICATION
Scheme 22
- Remove the battery terminal.
- Lift the vehicle.
- Remove the under cover.
- Loosen the drain plug and drain the transaxle oil.
- Remove the oil pan.
- Remove the oil filter.
- Remove the valve body (refer to Valve Body Disassembly in overhaul)
- Disconnect the VFS solenoid valve connector (A). see scheme 210: Identifying VFS Solenoid Valve Connector
- Remove the solenoid valve assembly (B).
INPUT SPEED SENSOR DESCRIPTION Sensor type Type : HALL SENSOR Operating voltage : DC 12V Current consumption : 22mA (Max) Function Input shaft speed sensor: Detect the input shaft rotation at the OD & REV retainer side to control oil pressure when shifting. Feedback control, clutch-clutch control, damper clutch control, shift range control, incorrect ratio control and sensor trouble detection signal. Connector
Scheme 23
Scheme 24
| Item | Inspection item | Standard value |
|---|---|---|
| Air gap | Input shaft speed sensor | 0.05in (1.3mm) |
| Sensor resistance | Input shaft speed sensor | Over 1 Mohms |
| Output voltage | HIGH | Over 4.8V |
| LOW | Below 0.8V |
VOLTAGE AND RESISTANCE SPECIFICATION
Scheme 25
- Remove the battery terminal.
- Remove the battery and battery tray.
- Remove the air duct.
- Remove the air cleaner assembly (refer to «REMOVAL»(ref-287431-S12728302022008061200000) )
- Remove the input shaft speed sensor connector (A). see scheme 214: Identifying Input Shaft Speed Sensor Connector
- Remove the input shaft speed sensor (A).
Identifying Inside Structure Of Output Speed Sensor. Scheme 26
OUTPUT SPEED SENSOR DESCRIPTION Sensor type Type : HALL SENSOR Output voltage : DC 12V Current consumption : 22mA (Max) Function Output shaft speed sensor : Detect the output shaft rpm (T/F DRIVE GEAR RPM) at the T/F drive gear Feedback control, clutch-clutch control, damper clutch control, shift range control, incorrect ratio control and sensor trouble detection signal. Connector
Scheme 27
| Item | Inspection item | Standard value |
|---|---|---|
| Air gap | Output shaft speed sensor | 0.033in (0.85mm) |
| Sensor resistance | Output shaft speed sensor | Over 1 Mohms |
| Output voltage | HIGH | Over 4.8V |
| LOW | Below 0.8V |
VOLTAGE AND RESISTANCE SPECIFICATION
TRANSAXLE OIL TEMPERATURE SENSOR DESCRIPTION Sensor type Type : Thermister Use available temperature :-40~160°C (-40~320°F) Function and feature Detect the temperature of ATF through the thermistor which is exposed outside. When shifting the range, it is used as the oil pressure control information. Connector
Scheme 28
| Temp.[°C (°F)] | Resistance (Kohms) | Temp.[°C (°F)] | Resistance (Kohms) |
|---|---|---|---|
| 40 (-40) | 139.5 | 80 (176) | 1.08 |
| 20 (-4) | 47.4 | 100 (212) | 0.63 |
| 0 (32) | 18.6 | 120 (248) | 0.38 |
| 20 (68) | 8.1 | 140 (284) | 0.25 |
| 40 (104) | 3.8 | 160 (320) | 0.16 |
| 60 (140) | 1.98 |
TEMPERATURE AND RESISTANCE SPECIFICATION
Shift Lever Position Reference Chart. Scheme 29
| Sensor type | Type : ROTARY Available temperature range : -40~150°C (-40~320°F) TORQUE : 10~12Nm (1.0~1.2kgf.m, 7~8lb-ft) |
|---|---|
| Function | Detect the position of select lever through the contact switch. It makes starting possible in "P" and "N". |
TRANSAXLE RANGE SWITCH DESCRIPTION
Scheme 30
Scheme 31
Scheme 32
- Remove the battery terminal.
- Remove the battery and battery tray.
- Remove the air duct.
- Remove the air cleaner assembly (refer to «REMOVAL»(ref-287431-S12728302022008061200000) )
- Disconnect the inhibitor switch connector (A). see scheme 229: Identifying Inhibitor Switch Connector
- Remove the control cable (A) from the manual control lever. see scheme 230: Identifying Control Cable
- Remove the inhibitor switch and manual control lever.