NEW FEATURES

Clutch Pressure Optimal Control

1. The TCM monitors the signals from various types of sensors, such as the transmission revolution sensor (NT), allowing the shift solenoid valve SL1, SL2, SL3, SL4, SL5 (Shift Control Solenoid Assembly), SLT (line pressure control solenoid assembly) and shift solenoid valve SLU (lock up control solenoid assembly) to minutely control the clutch pressure in accordance with engine output and driving conditions. As a result, smooth shift characteristics are achieved.

   

Clutch to Clutch Pressure Control

1. Clutch to clutch pressure control is used for shift control. As a result, shift control in the 2nd gear or above is possible without using the 1-way clutch, and the automatic transmission has been made lightweight and compact.

2. Using the fluid pressure circuit, which enables the clutches and brakes (C1, C2, C3, C4 and B1) to be controlled independently, and the high flow SL1, SL2, SL3, SL4 and SL5 shift solenoid valves, which directly control the line pressure, the TCM controls each clutch and brake accordingly with the optimum fluid pressures and timings in accordance with the information transmitted by the sensors, and then shifts the gears. As a result, highly responsive and excellent shift characteristics have been achieved.

   

Powertrain Cooperative Control

1. Through cooperative control with ETCS-i (Electronic Throttle Control System-intelligent) and ESA (Electronic Spark Advance), and electronic control of the engagement and release speed of the clutch and brake hydraulic pressures, excellent response and shift shock reduction have been achieved.

   

Coast Downshift Control

1. The TCM performs downshift control to prevent the engine speed from decreasing, thus keeping fuel cut control operating for as long as possible. In this way, the fuel economy is improved.

2. In this control, the transmission downshifts from 8th to 7th, 7th to 6th and then 6th to 5th before fuel cut control ends when the vehicle is decelerated in the 8th gear, so that fuel cut control continues operating. In addition, the TCM performs downshifting when the vehicle is decelerated both in the 6th and 7th gears.

   

Multi-mode Transmission

1. The driver can select the desired gear range by moving the shift lever to "+" (forward) or "-" (backward) while the shift lever is in S.

2. When the vehicle is being driven at a prescribed speed or higher, any attempt to shift to a lower range by operating the shift lever will not be executed, in order to protect the automatic transmission. In this case, the ECM sounds the buzzer in the combination meter assembly twice to alert the driver.

   

Lock-up Timing Control

1. The TCM operates lock-up timing control in order to improve fuel economy performance.

   Figure 1. Lock-up Operating Range:

   

   Lock-up Timing Control Operation

   Gear	Shift Position and Shift Range
   	D, S8	S7	S6	S5
   1st	X	X	X	X
   2nd	X	X	X	X
   3rd	X	X	X	X
   4th	X	X	X	X
   5th	○	○	○	○
   6th	○	○	○	-
   7th	○	○	-	-
   8th	○	-	-	-

   ○: Operates

   X: Does not operate

   -: Not applicable

Flex Lock-up Clutch Control

1. During acceleration, partial control of the power transmission between the lock-up clutch and torque converter greatly boosts transmission efficiency in accordance with the driving conditions, improving fuel economy.

2. Even when the vehicle is decelerating (the accelerator pedal is released), flex lock-up clutch control operates. As a result, the fuel-cut area is expanded and fuel economy is improved.

3. By allowing flex lock-up clutch control to continue operating during gearshifts, smooth torque transmission is obtained. As a result, fuel economy and drivability are improved.

   

   Figure 2. Flex Lock-up Operating Range:

   

   Flex Lock-up Timing Control Operation

   Gear	Shift Position and Shift Range (Fixed Shift Range Mode)
   	D, S8	S7	S6	S5
   1st	X	X	X	X
   2nd	X	X	X	X
   3rd	X	X	X	X
   4th	X	X	X	X
   5th	○	○	○	○
   6th	○	○	○	-
   7th	○	○	-	-
   8th	○	-	-	-

   Tech Tips

   ○: Flex lock-up clutch control operates.

   X: Flex lock-up clutch control does not operate.

   -: Not applicable gear

Artificial Intelligence Shift Control (AI-shift Control)

• AI-shift control determines optimal transmission control based on input signals and automatically changes the shift pattern. As a result, a high caliber of transmission operation is achieved.

• AI-shift control includes road condition support control and a driver's intention support.

• AI-shift control is performed with the shift lever in D, based on the accelerator pedal and brake operation data. AI-shift control will be canceled when the shift lever is moved to a position other than D.

1. Road Condition Support Control

   
   

   • The TCM identifies the throttle valve opening angle, accelerator pedal opening angle and vehicle speed to determine whether the vehicle is being driven uphill or downhill. Unnecessary upshift is restrained to automatically achieve optimal drive force at all times while driving uphill. Downshift is automatically conducted to achieve optimal engine brake force, while driving downhill.

   

2. Driver's Intention Support Control

   
   

   • Driver's intention support control is estimated based on the accelerator pedal operation, vehicle condition and a shift pattern that is well-suited to the driver is selected without operating the switch.

   
   

   1. Sudden Accelerator Pedal Release Control

   
   

   • When the accelerator pedal is released suddenly, the transmission is kept in gear as long as possible, which improves engine braking force.

     

   2. Sudden Accelerator Pedal Depress Control

   
   

   • When the accelerator pedal is depressed suddenly, downshifting occurs earlier ensuring improved acceleration response.

     

   3. Downshifting Control During Hard Braking

   
   

   • High engine braking force and good re-acceleration response have been achieved by actively downshifting during deceleration when hard braking is made.

     

Blipping Downshift Control

1. The blipping downshift control regulates each clutch and brake using the clutch to clutch pressure control, allowing them to be engaged smoothly and disengaged quickly. In addition, fuel injection volume is increased and engine speed is boosted by the powertrain cooperative control, thus ensuring engine brake force. In this way, a smooth and quick downshift is achieved. In addition, further quick down-shifting has been available by directly controlling clutch pressure.

   Tech Tips

   When the ATF and engine coolant temperature is low, blipping down shift control will not be performed.

   

Engine Stall Avoidance Control

• When an engine stall has occurred, the TCM suspects an ON malfunction of the linear solenoid valve SLU (lock-up control solenoid assembly), and engine stall avoidance control may be engaged by release of the C1 clutch or C3 clutch when the engine is started again. While engine stall avoidance control is engaged, creeping does not occur after the engine is restarted, even when in the D, S, or R shift position.

• Slowly stepping on the accelerator pedal until the vehicle starts to move with the brake off engages the clutch, which makes departure possible.

• When the linear solenoid valve SLU (lock-up control solenoid assembly) is normal, running at a constant speed for a short while with the engine speed from 1000 rpm to 3000 rpm releases engine stall avoidance control. The control can also be released by using Techstream and implementing the diagnosis code deletion procedure for the TCM. Furthermore, it is possible to carry out the deletion procedure even without the diagnosis code being entered.

• When the vehicle departs, and then the linear solenoid valve SLU (lock-up control solenoid assembly) malfunctions or the vehicle stops before the above-mentioned conditions are reached, engine stall avoidance control is not released, so again creeping does not occur.

Torque Converter

1. A compact, lightweight and high-capacity torque converter assembly is used. The torque converter supports lock-up clutch control, thus improving fuel economy.

   

   *1	Lock-up Damper	*2	1-way Clutch
   *3	Turbine Runner	*4	Lock-up Clutch
   *5	Stator	*6	Pump Impeller

Oil Pump

1. The oil pump is operated by the torque converter. It lubricates the planetary gear units and supplies operating fluid pressure for hydraulic control. The oil pump drive gear is continually driven by the engine via the pump impeller. The pump has sufficient capacity to supply the necessary fluid pressure throughout all speed ranges, as well as in reverse.

2. The pump cover is made of aluminum to reduce weight.

3. A pump cover with an integrated piston cylinder for the No. 1 brake (B1) is used.

   

   *1	Pump Body	*2	Drive Gear
   *3	Driven Gear	*4	Stator Shaft
   *5	Pump Cover	-	-

ATF Filling Procedure

1. An ATF filling procedure is used in order to improve the accuracy of the ATF level when the transmission is being repaired or replaced. As a result, the oil filler tube and the oil level gauge used in a conventional automatic transmission have been discontinued, eliminating the need to inspect the fluid level as a part of routine maintenance. For details about the ATF filling procedures, refer to the Repair Manual.

   

   *1	Refill Plug	*2	Overflow Plug
   *a	Oil Level	-	-

Planetary Gear

1. The gear train consists of 4 multi-plate clutches, 2 multi-plate brakes, a 1-way clutch, and 2 sets of planetary gears each consisting of a sun gear, a pinion gear and a ring gear.

2. Gear noise has been reduced through the optimized gears including the number of teeth, arrangements, and contact surfaces.

   

   *1	No. 1 Brake (B1)	*2	No. 4 Clutch (C4)
   *3	Front Planetary Gear Unit	*4	Rear Planetary Gear Unit
   *5	No. 2 Clutch (C2)	*6	No. 2 Brake (B2)
   *7	No. 1 1-way Clutch (F1)	*8	No. 1 Clutch (C1)
   *9	No. 3 Clutch (C3)	-	-

   

   *1	Input Shaft	*2	Front Planetary Sun Gear
   *3	Front Planetary Ring Gear	*4	Front Planetary Gear Unit
   *5	Intermediate Shaft	*6	Rear Planetary Middle Sun Gear
   *7	Rear Planetary Ring Gear	*8	Rear Planetary Gear Unit
   *9	Rear Planetary Rear Sun Gear	*10	Output Shaft
   *11	Rear Planetary Short Pinion Gear	*12	Rear Planetary Long Pinion Gear
   *13	Front Planetary Pinion Gear	-	-
   C1	No. 1 Clutch	C2	No. 2 Clutch
   C3	No. 3 Clutch	C4	No. 4 Clutch
   B1	No. 1 Brake	B2	No. 2 Brake
   F1	No. 1 1-way Clutch	-	-

Centrifugal Fluid Pressure Canceling Mechanism

1. The clutch engagement force during shift transmission is affected by the centrifugal fluid pressure that acts on the fluid inside the piston fluid pressure chamber (referred to as "chamber A"), in addition to the original clutch pressure regulated by the valve body. In order to eliminate the influence caused by the centrifugal fluid pressure, the canceling fluid pressure chamber (referred to as "chambers") is provided on the opposite side of chamber A to cancel out the centrifugal fluid pressure. As a result, the centrifugal fluid pressure canceling mechanism provides responsive, smooth shift transmission.

   

   *1	Piston	*2	No. 4 Clutch (C4)
   *3	No. 3 Clutch (C3)	*4	No. 1 Brake (B1)
   *a	Chamber A	*b	Chamber B

2. Chamber B is filled by fluid supplied to the shaft for lubrication. As a result of filling chamber B, the same amount of fluid pressure is present on both sides of the piston due to centrifugal force. This cancels the effects of fluid pressure on the piston caused by centrifugal force. Accordingly, it is not necessary to discharge the fluid through the use of a check ball, and highly responsive and smooth shifting characteristics are achieved.

   

   	Target fluid pressure		Centrifugal fluid pressure applied to chamber A
   	Centrifugal fluid pressure applied to chamber B	-	-

Transmission Valve Body

1. The transmission valve body assembly consists of the upper and lower valve bodies and 9 shift solenoid valves.

   

   *1	Shift Solenoid Valve SLU (Lock Up Control Solenoid Assembly)	*2	Upper Valve Body
   *3	Plate	*4	Lower Valve Body
   *5	Shift Solenoid Valve SLT (Line Pressure Control Solenoid Assembly)	*6	Shift Solenoid Valve SL1 (Shift Control Solenoid Assembly)
   *7	Shift Solenoid Valve SL4 (Shift Control Solenoid Assembly)	*8	Shift Solenoid Valve SL2 (Shift Control Solenoid Assembly)
   *9	Shift Solenoid Valve SL5 (Shift Control Solenoid Assembly)	*10	Shift Solenoid Valve SL3 (Shift Control Solenoid Assembly)
   *11	Shift Solenoid Valve SC1 (Transmission 3-way Solenoid Assembly)	*12	Shift Solenoid Valve SC2 (Transmission 3-way Solenoid Assembly)

Shift Solenoid Valves SL1, SL2, SL3, SL4 ,SL5 (Shift Control Solenoid Assembly), SLT (Line Pressure Control Solenoid Assembly) and SLU (Lock Up Control Solenoid Assembly)

1. In order to provide a hydraulic pressure that is proportional to the current that flows to the solenoid coil, shift solenoid valves SL1, SL2, SL3, SL4, SL5, SLU and SLT linearly control the line pressure and clutch and brake engagement pressure based on the signals from the TCM.

2. The shift solenoid valves SL1, SL2, SL3, SL4 and SL5 are large flow linear solenoid valves that can supply more pressure than conventional ones. These shift solenoid valves control engagement elements by directly regulating the line pressure without using the pressure regulation valve or the pressure reduction valve. Thus, the number of valves and the length of the valve body fluid passage have been reduced, the shifting response has been improved and the shift shock has been minimized.

   Figure 3. Shift Solenoid Valve SL1, SL4 and SL5 (Shift Control Solenoid Assembly)

   

   *1	Spool Valve
   *2	Hydraulic Pressure
   *3	Sleeve
   *4	Current

   Figure 4. Shift Solenoid Valve SL2 and SL3 (Shift Control Solenoid Assembly)

   

   *1	Spool Valve
   *2	Hydraulic Pressure
   *3	Sleeve
   *4	Current

   Figure 5. Shift Solenoid Valve SLU (Lock Up Control Solenoid Assembly)

   

   *1	Spool Valve
   *2	Hydraulic Pressure
   *3	Sleeve
   *4	Current

   Figure 6. Shift Solenoid Valve SLT (Line Pressure Control Solenoid Assembly)

   

   *1	Spool Valve
   *2	Hydraulic Pressure
   *3	Sleeve
   *4	Current

Shift Solenoid Valves SC1 and SC2

1. A 3-way solenoid valve is used for the shift solenoid valves SC1 and SC2.

2. A filter is provided at the tip of the shift solenoid valves to further improve operational reliability.

   Figure 7. Shift Solenoid Valve SC1 (Transmission 3-way Solenoid Assembly)

   

   Figure 8. Shift Solenoid Valve SC2 (Transmission 3-way Solenoid Assembly)

   

Transmission Revolution Sensor

1. This automatic transmission uses the transmission revolution sensor (NT) and Transmission Revolution Sensor (SP2). Thus, the TCM can detect the timing of the shifting of the gears and appropriately control the engine torque and hydraulic pressure in response to various conditions. These transmission revolution sensors are Hall type.

2. The transmission revolution sensor (NT) detects the input speed of the transmission. The input shaft is used as the timing rotor for this sensor.

3. The Transmission Revolution Sensor (SP2) detects the speed of the output shaft. The rear planetary ring gear is used as the timing rotor for this sensor.

4. The Hall type transmission revolution sensor consists of a magnet and Hall IC. The Hall IC converts the changes in the magnetic flux density that occur through the rotation of the timing rotor into an electric signal, and outputs the signal to the TCM.

   

   *1	Input Shaft	*2	Transmission Revolution Sensor (NT)
   *3	Transmission Revolution Sensor (SP2)	*4	Rear Planetary Ring Gear

ATF Temperature Sensor

1. The No. 1 ATF temperature sensor is installed in the transmission valve body assembly for direct detection of the fluid temperature.

2. The No. 1 ATF temperature sensor is used for the revision of clutch and brake pressures to maintain a smooth shift quality every time.

   

   *1

   Transmission Valve Body Assembly

   *2

   No. 1 ATF Temperature Sensor

3. The No. 2 ATF temperature sensor is measures the temperature of the ATF to the oil cooler.

   

   *1

   No. 2 ATF Temperature sensor

   -

   -

Park/Neutral Position Switch and Transmission Control Switch

1. The park/neutral position switch assembly sends the C and NSW signals to the ECM.

2. The park/neutral position switch assembly sends the PA, A, B and C signals to the TCM.

3. The transmission control switch is installed inside the transmission floor shift assembly to detect the S mode position and to inform the ECM.

4. The transmission control switch detects whether the shift lever is in D or S, and detects the operating conditions of the shift lever "+" (forward) or "-" (backward) when the shift lever is in S, and sends signals to the ECM.

   

Transmission Power Flow

○: On

●: In Accordance with Flex Lock-up

X: Off

○: On

●: In Accordance with Flex Lock-up

X: Off

○: Operates

-: Does not Operate

Figure 9. 1st Gear (S1)

	Output		Input
	Operates	-	-

Figure 10. 1st Gear (D, S2 to S8)

	Output		Input
	Operates	-	-

Figure 11. 2nd Gear (D, S)

	Output		Input
	Operates	-	-

Figure 12. 3rd Gear (D, S)

	Output		Input
	Operates	-	-

Figure 13. 4th Gear (D, S)

	Output		Input
	Operates	-	-

Figure 14. 5th Gear (D, S)

	Output		Input
	Operates	-	-

Figure 15. 6th Gear (D, S)

	Output		Input
	Operates	-	-

Figure 16. 7th Gear (D, S)

	Output		Input
	Operates	-	-

Figure 17. 8th Gear (D, S)

	Output		Input
	Operates	-	-

Figure 18. Reverse Gear

	Output		Input
	Operates	-	-

SHIFT LOCK SYSTEM

1. The shift lock system prevents the shift lever from being moved to any position other than P, unless the engine switch is turned on (IG) and the brake pedal is depressed. This prevents the vehicle from starting off suddenly.

2. The shift lock system is controlled by the shift lock control ECU, and it has a shift lock function.

3. The shift lock control ECU has a built-in P detection switch to detect the shift lever position, and receives input signals from the stop light switch assembly and engine switch. Upon receiving these signals, the shift lock control ECU turns on the shift lock solenoid assembly in order to release the shift lock.

   Figure 19. System Diagram

   

   Figure 20. Parts Location

   

   *1	Engine Switch	*2	Certification ECU (Smart Key ECU Assembly)
   *3	Stop Light Switch Assembly	*4	Transmission Floor Shift Assembly
   *5	P Detection Switch	*6	Shift Lock Solenoid Assembly
   *7	Shift Lock Control ECU	*8	Shift Lock Release Button
   *9	Shift Lock Release Button Cap	-	-