Part 1
Transmission Operation
Transmission Operation Overview
Transmission operation is controlled by the PCM.
Torque Converter
This transmission uses a torque converter with the following elements:
- Impeller
- Turbine
- Reactor
- Torque Converter Clutch (TCC)
For component information, refer to Torque Converter Torque Converter.
Planetary Gearsets
Operation of this transmission involves the use of 2 planetary gearsets that have the following components:
- Front (single planetary gearset)
- One sun gear
- One planetary carrier with 4 gears
- One ring gear
- Rear (ravigneaux planetary gearset)
- Two sun gears of different sizes
- Three short planetary gear pinions meshing with the sun gears
- Three long planetary gear pinions meshing with the sun gears
- One planetary carrier
- One ring gear
Apply Clutches
This transmission uses the following clutches to operate the 2 planetary gearsets:
- Forward clutch (A)
- Direct clutch (B)
- Intermediate clutch (C)
- Low/reverse clutch (D)
- Overdrive clutch (E)
- Low One-Way Clutch (OWC)
For information about planetary gearsets or the apply clutches, refer to Mechanical Components and Functions Mechanical Components and Functions.
Hydraulic System
The hydraulic operation of this transmission includes the following components:
- Main control assembly
- Pump assembly with filter
- Torque converter
- Apply components (clutches)
For component information, refer to Hydraulic System Hydraulic System.
Electronic Operation
The PCM controls the operation of this transmission with the following solenoids:
- Line Pressure Control (LPC) solenoid
- Shift Solenoid A (SSA)
- Shift Solenoid B (SSB)
- Shift Solenoid C (SSC)
- Shift Solenoid D (SSD)
- Shift Solenoid E (SSE)
- TCC (Torque Converter Clutch) solenoid
For solenoid information, refer to Transmission Electronic Control System Transmission Electronic Control System.
Park Position
Mechanical Operation
Apply components:
- Park pawl engaged holding the park gear (output shaft) stationary
- Low/reverse clutch (D) applied
Planetary Gearset Operation
Front planetary gearset driving components:
- Ring gear (input shaft)
Front planetary gearset driven components:
- Planetary carrier
Front planetary gearset held components:
- Sun gear (splined to pump assembly)
Rear planetary gearset driving components:
- None
Rear planetary gearset driven components:
- None
Rear planetary gearset held components:
- Planetary carrier
- Ring gear (output shaft)
Park Position Clutch Application Chart
- H = Hold Clutch
For component information, refer to Mechanical Components and Functions Mechanical Components and Functions.
Park Position Power Flow
Hydraulic Operation
Line pressure hydraulic circuits:
- The position of the main regulator valve controls line pressure. The position of the main regulator valve is dependent on the pressure applied to it by the LPC (Line Pressure Control) solenoid through the VFS5 circuit.
- The main regulator valve varies pressure in the PUMP circuit by controlling hydraulic flow from the SCHG circuit into the pump suction circuit.
- Line pressure is supplied to the:
- manual valve.
- lubrication control valve.
- converter release regulator valve.
- bypass clutch control regulator valve.
- solenoid pressure regulator valve.
- D1 latch and regulator valves.
Torque converter circuits:
- When the TCC (Torque Converter Clutch) is released, the converter release regulator valve applies pressure to the torque converter through the CREL circuit to release the TCC (Torque Converter Clutch).
- CREL pressure exits the torque converter through the CAPLY circuit to the bypass clutch control regulator valve.
- The bypass clutch control regulator valve directs the pressure from the CAPLY circuit back to the converter release regulator valve through the CAPLY EX circuit.
- The converter release regulator valve directs the pressure from the CAPLY EX circuit to the drain back valve through the DBACK circuit.
Cooler and lubrication hydraulic circuits:
- The lubrication control valve directs line pressure to the transmission fluid cooler or the thermal bypass valve through the COOLF circuit.
- When the transmission fluid exits the transmission fluid cooler or thermal bypass valve, it provides lubrication to the transmission through the LUBE circuit. For information about transmission lubrication, refer to Mechanical Components and Functions Mechanical Components and Functions.
Solenoid hydraulic circuits:
- The solenoid pressure regulator valve supplies regulated line pressure to the shift, LPC (Line Pressure Control) and TCC (Torque Converter Clutch) solenoids through the SREG hydraulic circuit.
- The LPC (Line Pressure Control) solenoid applies varying pressure to the main regulator valve through the VFS5 hydraulic circuit. The LPC (Line Pressure Control) solenoid regulates line pressure by controlling the position of the main regulator valve.
- SSD (Shift Solenoid D) supplies pressure to the solenoid multiplex valve through the VFS4 circuit.
- The position of the solenoid multiplex valve allows pressure from the VFS4 circuit to be directed to the D1 and D2 latch and regulator valves through the CL DC circuit to position the valves for low/reverse clutch (D) application.
Clutch hydraulic circuits:
- Line pressure is supplied by the pump to the D1 latch and regulator valves.
- Regulated line pressure from the D1 regulator valve is supplied to the low/reverse clutch (D) to apply the clutch.
For hydraulic circuit information, refer to Hydraulic Circuits Hydraulic Circuits.
Electrical Operation
Solenoid operation:
Park Position Solenoid Operation Chart
CB = Clutch brake
NC = Normally closed
NH = Normally high
NL = Normally low
For solenoid information, refer to Transmission Electronic Control System Transmission Electronic Control System.
Reverse Position
Mechanical Operation
Apply components:
- Low/reverse clutch (D) applied
- Direct clutch (B) applied
Planetary Gearset Operation
Front planetary gearset driving components:
- Ring gear (input shaft)
Front planetary gearset driven components:
- Planetary carrier
Front planetary gearset held components:
- Sun gear (splined to pump assembly)
Rear planetary gearset driving components:
- Sun gear No. 2
Rear planetary gearset driven components:
- Ring gear (output shaft)
Rear planetary gearset held components:
- Planetary carrier
Reverse Position Clutch Application Chart
- D = Drive Clutch
- H = Hold Clutch
For component information, refer to Mechanical Components and Functions Mechanical Components and Functions.
Reverse Position Power Flow
Hydraulic Operation
Line pressure hydraulic circuits:
- The position of the main regulator valve controls line pressure. The position of the main regulator valve is dependent on the pressure applied to it by the LPC (Line Pressure Control) solenoid through the VFS5 circuit.
- The main regulator valve varies pressure in the PUMP circuit by controlling hydraulic flow from the SCHG circuit into the pump suction circuit.
- Line pressure is supplied to the:
- manual valve.
- lubrication control valve.
- converter release regulator valve.
- bypass clutch control regulator valve.
- solenoid pressure regulator valve.
- D1 latch and regulator valves.
- In reverse, the manual valve directs line pressure to the No. 1 shuttle valve and the solenoid multiplex valve through the REV circuit.
- The No. 1 shuttle ball directs line pressure to the clutch B regulator valve.
Torque converter circuits:
- When the TCC (Torque Converter Clutch) is released, the converter release regulator valve applies pressure to the torque converter through the CREL circuit to release the TCC (Torque Converter Clutch).
- CREL pressure exits the torque converter through the CAPLY circuit to the bypass clutch control regulator valve.
- The bypass clutch control regulator valve directs the pressure from the CAPLY circuit back to the converter release regulator valve through the CAPLY EX circuit.
- The converter release regulator valve directs the pressure from the CAPLY EX circuit to the drain back valve through the DBACK circuit.
Cooler and lubrication hydraulic circuits:
- The lubrication control valve directs line pressure to the transmission fluid cooler or the thermal bypass valve through the COOLF circuit.
- When the transmission fluid exits the transmission fluid cooler or thermal bypass valve, it provides lubrication to the transmission through the LUBE circuit. For information about transmission lubrication, refer to Mechanical Components and Functions Mechanical Components and Functions.
Solenoid hydraulic circuits:
- The solenoid pressure regulator valve supplies regulated line pressure to the shift, LPC (Line Pressure Control) and TCC (Torque Converter Clutch) solenoid through the SREG hydraulic circuit.
- The LPC (Line Pressure Control) solenoid applies varying pressure to the main regulator valve through the VFS5 hydraulic circuit. The LPC (Line Pressure Control) solenoid regulates line pressure by controlling the position of the main regulator valve.
- SSD (Shift Solenoid D) supplies pressure to the solenoid multiplex valve through the VFS4 circuit.
- The position of the solenoid multiplex valve allows pressure from the VFS4 circuit to be directed to the D1 and D2 latch and regulator valves through the CLDC circuit to position the valves for low/reverse clutch (D) application.
- SSB (Shift Solenoid B) supplies pressure to the clutch B regulator and latch valves to position the valves for direct clutch (B) application.
Clutch hydraulic circuits:
- Line pressure is supplied by the pump to the D1 latch and regulator valves.
- Regulated line pressure from the D1 regulator valve is supplied to the low/reverse clutch (D) to apply the clutch.
- Line pressure is supplied by the manual valve to the clutch B latch and regulator valves.
- Regulated line pressure from the clutch B regulator valve is supplied to the direct clutch (B) to apply the clutch.
For hydraulic circuit information, refer to Hydraulic Circuits Hydraulic Circuits.
Electrical Operation
Solenoid operation:
Reverse Position Solenoid Operation Chart
CB = Clutch brake
NC = Normally closed
NH = Normally high
NL = Normally low
For solenoid information, refer to Transmission Electronic Control System Transmission Electronic Control System.
Neutral Position
Mechanical Operation
Apply components:
- Low/reverse clutch (D) applied
Planetary Gearset Operation
Front planetary gearset driving components:
- Ring gear (input shaft)
Front planetary gearset driven components:
- Planetary carrier
Front planetary gearset held components:
- Sun gear (splined to pump assembly)
Rear planetary gearset driving components:
- None
Rear planetary gearset driven components:
- None
Rear planetary gearset held components:
- Planetary carrier
Neutral Position Clutch Application Chart
- H = Hold Clutch
For component information, refer to Mechanical Components and Functions Mechanical Components and Functions.
Neutral Position Power Flow
Hydraulic Operation
Line pressure hydraulic circuits:
- The position of the main regulator valve controls line pressure. The position of the main regulator valve is dependent on the pressure applied to it by the LPC (Line Pressure Control) solenoid through the VFS5 circuit.
- The main regulator valve varies pressure in the PUMP circuit by controlling hydraulic flow from the SCHG circuit into the pump suction circuit.
- Line pressure is supplied to the:
- manual valve.
- lubrication control valve.
- converter release regulator valve.
- bypass clutch control regulator valve.
- solenoid pressure regulator valve.
- D1 latch and regulator valves.
Torque converter circuits:
- When the TCC (Torque Converter Clutch) is released, the converter release regulator valve applies pressure to the torque converter through the CREL circuit to release the TCC (Torque Converter Clutch).
- CREL pressure exits the torque converter through the CAPLY circuit to the bypass clutch control regulator valve.
- The bypass clutch control regulator valve directs the pressure from the CAPLY circuit back to the converter release regulator valve through the CAPLY EX circuit.
- The converter release regulator valve directs the pressure from the CAPLY EX circuit to the drain back valve through the DBACK circuit.
Cooler and lubrication hydraulic circuits:
- The lubrication control valve directs line pressure to the transmission fluid cooler or the thermal bypass valve through the COOLF circuit.
- When the transmission fluid exits the transmission fluid cooler or thermal bypass valve, it provides lubrication to the transmission through the LUBE circuit. For information about transmission lubrication, refer to Mechanical Components and Functions Mechanical Components and Functions.
Solenoid hydraulic circuits:
- The solenoid pressure regulator valve supplies regulated line pressure to the shift, LPC (Line Pressure Control) and TCC (Torque Converter Clutch) solenoid through the SREG hydraulic circuit.
- LPC (Line Pressure Control) solenoid applies varying pressure to the main regulator valve through the VFS5 hydraulic circuit. LPC (Line Pressure Control) solenoid regulates line pressure by controlling the position of the main regulator valve.
- SSD (Shift Solenoid D) supplies pressure to the solenoid multiplex valve through the VFS4 circuit.
- The position of the solenoid multiplex valve allows pressure from the VFS4 circuit to be directed to the D1 latch and regulator valves through the CL DC circuit to position the valves for low/reverse clutch (D) application.
Clutch hydraulic circuits:
- Line pressure is supplied by the pump to the D1 latch and regulator valves.
- Regulated line pressure from the D1 regulator valve is supplied to the low/reverse clutch (D) to apply the clutch.
For hydraulic circuit information, refer to Hydraulic Circuits Hydraulic Circuits.
Electrical Operation
Solenoid operation:
Neutral Position Solenoid Operation Chart
CB = Clutch brake
NC = Normally closed
NH = Normally high
NL = Normally low
a Solenoid state changes if vehicle is moving forward with the selector lever in the NEUTRAL position.
For solenoid information, refer to Transmission Electronic Control System Transmission Electronic Control System.
