Automatic transmission-37
power transmission Automatic 3rd-Gear and manual 3rd-Gear
In automatic and manual 3rd-Gear, the drive of transmission reaches the front cylinder through the input shaft. In this condition,
the operating principle of the transmission is shown as follows:
The engagement of clutch C2 drives the front sun gear
The engagement of clutch C1 drives the planetary gear carrier
The forward central gear and planetary gear carrier rotate in the same speed clockwise. So, there is not relative motion
between the forward central gear and planetary gear.
The gear ring and output shaft rotate in the speed of output shaft, and makes the moves forwardly.
The engagement of clutch C4 is through the 3-4 one-way clutch (OWC) and make the engine to provide the brake force
in overspeed.
Control:
In stable status, the status of solenoid valve and valve is shown as follows:
The solenoid valve S1 is powered off; Solenoid valve S2 is powered off
When the solenoid valve S1 and S2 is powered off, 2-3 and 3-4 shift valve are kept in 3rd-Gear position through the line
pressure 500.
1-2 Gear shifting valve is kept in 3rd-Gear position by the oil pressure of S1 and S2.
The (line pressure)oil form the 1-2 Gear shifting valve flows into the brake belt combination regulating valve directly and
flows into the 2-3 Gear shifting valve.
The brake belt combination regulating valve provides the 2nd-Gear oil (controlled by the product of line pressure and valve)
to the brake belt feed loop(BAF).
The brake belt feed loop directly provides the oil to:
External combination part of front servo
When the transmission is shifted to 1st-Gear, the 1-2 Gear shifting valve provides the oil drainage port.
When the transmission is in 4th –Gear position, it will use the 3-4 Gear shifting valve.
The 2nd-Gear oil of 2-3 Gear shifting valve flows into the 3rd-gear loop directly .
The 3rd-Gear oil from the 2-3 Gear shifting valve flows into the clutch combination regulating valve and sequence valve of
4-3 Gear directly.
The clutch combination regulating valve provides the oil of clutch attachment feed loop (controlled by the product of line
pressure of 500 and valve ratio) (CAF).
CAF directly provides the oil to :
clutch C1
Sequence valve of 4-3 Gear
In 4-3 Gear shifting valve, the CAF oil is changed to the release fluid of B1 (B1R-F), it cause the closing of brake belt 1
through the 3-4 Gear shifting valve to spring bottom of 4-3 gear sequence valve and release side of front servo.
The drive force (line pressure ) is sent to the clutch C4 through the 3-4 Gear shifting valve to engage the clutch C4 .
Refer to Figure 5.6 and Table 5.7.
Table 5.7
Table of participating condition of each unit in automatic and manual 3rd –Gear
Clutch
Name of participation unit
Automatic and manual
3
rd –Gear
Automatic transmission-38
Figure 5.6 Automatic 3
rd –Gear-manual 3
rd-gear
Automatic transmission-39
Power transmission locking of automatic and manual 3rd-Gear
When the automatic 3rd-Gear and manual 3rd-Gear is locked, the drive of transmission is basically same as that in automatic 3rd-
Gear. But it provide the variable torque drive without slide for the application of torque converter locking clutch.
Control:
The control for the automatic 3
rd-Gear locking and manual 3rd-Gear locking is basically same as that for automatic 3rd –Gear. But
it should be described additionally that the automatic 3
rd-Gear and manual 3rd-gear locking needs the action for variable torque
clutch loop by solenoid valve S7.
When the solenoid valve S7 is opened, the variable torque clutch control valve is closed and allow the oil feed of S7 loop pass
through the solenoid valve S7 to drainage port. It makes the control valve moves to the clutch combination position.
The loop oil from the line 500 flows into the combination part of variable torque clutch through the converter clutch control
valve through the action of variable torque clutch control valve.
The variable torque clutch release oil is drained from the variable torque clutch control valve.
The torque converter loop oil flows into the oil cooler and lubrication loop through the variable clutch control valve.
Refer to Figure 5.7 and table 5.8.
Table 5.8Participating condition of each unit in automatic and manual 3rd-Gear locking
Automatic 3rd-Gear locking and
manual 3
rd-gear locking
Name of participation unit
Automatic transmission-40
Figure 5.7 Automatic 3
rd –Gear locking and manual 3
rd-Gear locking
Automatic transmission-41
In automatic 4th-Gear (overspeed gear), the drive of transmission is sent to the front clutch cylinder through the input shaft. The
operation principle of each function assembly of transmission is shown as follows:
The engagement of clutch C1 drives the planetary gear carrier rotates in clockwise rotation.
The engagement of B1 brake belt makes the reverse sun gear to stop.
When the planetary gear carrier rotates, the long planetary gear rotates around the static reverse sun gear, at the same time, it
rotates around its axial line to drive the gear ring and output shaft to generate the forward movement in the speed higher than
that of input shaft (i.e. overspeed) clockwise.
The forward central gear rotates in the speed higher than input shaft and is more than the speed when 3-4 one-way clutch
(OWC) is engaged.
The engagement of clutch C2 is used to reduce the speed difference generated by 3-4 one-way clutch (OWC).
Control:
In the stable status, the status of solenoid valve and valve is shown as follows:
The solenoid valve S1 is powered on ; S2 is powered off.
When the solenoid valve S1 is powered on, the small end of 3-4 shift valve is in 4th-Gear position for the pressure of line 500.
When the solenoid valve S2 is powered off, the large opening of 2-3 shifting valve is in 4th- Gear position for the pressure of
line 500.
The 1-2 Gear shifting valve is kept in 4th-Gear position for the pressure of S2 oil loop.
The 2nd-Gear loop oil (line pressure) from the 1-2 shift valve flows into the brake belt combination regulating valve and 2-3
shift valve directly.
The brake belt combination regulating valve provides the 2nd-Gear loop oil for the brake belt attachment loop (BAF) (adjusted
by product of line pressure and valve ratio)
The brake belt combination lip oil is directly supplied to:
External combination part of front servo
Enter into the internal combination part of front servo piston through 3-4 shift valve
The 1st-Gear-2 switch valve provides a oil-drain port when the transmission is switched to 1st-Gear.
The 2nd-Gear loop oil in 2-3shift valve flows into the 3rd-Gear loop directly.
The 3rd-Gear loop oil from the 2-3 shift valve flows into the clutch combination regulating valve and 4th-Gear-3 sequence
valve directly
The clutch combination regulator valve supplies the oil for the clutch combination loop (CAF) (Regulated by the product of
line pressure and valve rate)
CAF oil is directly supplied to:
clutch C1
4th-Gear-3 sequence valve
The drive oil(line pressure) form the manual-operated valve forces the engagement of clutch C2
Refer to Figure 5.8 and Table 5.9.
Table 5.9
Participating condition of each unit in automatic 4th –Gear (overspeed Gear)
clutch
Name of participation unit
Automatic 4
th-Gear
(overspeed Gear)
Automatic transmission-45
Diagnosis and test
Test system
1. Recommended test equipment and program
The test equipment and control unit for design will be used for the test of all vehicles. The parts for transmission test includes:
Tester for service after sales
Special vehicle for test
2. Tester for service after sales
After the special programming, the tester equipped with special car test software can be used to test the specified system and unit.
The program allows the normal communication between the transmission control units (TCUs) .
The computer needs the required information from the customer and select the necessary data through the manual. For example:
view the code, clear the error code and make the real-time operation. For detailed operating instruction refer to user’s manual.
The equipment can be used by the trained specialized persons, such as technician, machinist to test the electronic and loop
problem related to transmission. The testable information includes: the engine speed, rode (shaft speed), transmission fluid
temperature, position of throttle position, status of solenoid valve and gear and position of operating lever. Additionally, it can be
used to detect the current and stored problem.
3. Description of TCU pin
The description of TCU pin code had been listed in Table 6.1.1
For description of wire bunch refer to Figure 6.1.1
Pin No. Function Type 2WD description
A14 Public grounding GND
● Negative pole of TCU supply, connected to negative pole of
battery.
A13 Nonuse
--
○ -----
A12 M ode indicator la mp
Snowland mode OP
● Indicate that select the “Snowland M ode” operating method.
A11 Parking-Gear indicator lamp O P
● T he drive instrum ent panel indicator la mp indicates tha t is in
the “Parking G ear”
A10 Reverse-Gear indicator lamp OP
● T he drive instrum ent panel indicator la mp indicates tha t is in
“ Revers e G ear”
A9 N-G ear indicator lamp O P
● T he drive instrum ent panel indicator la mp indicates tha t is in
“Idle N Gear”
A8 Nonuse -- ○ -----
A7 Nonuse -- ○ -----
A6 M ode indicator la mp
dynamic mode OP
● Indicate that select the “ dyna m ic mode” operating method.
A5 Nonuse ―― ○ ---――
A4 Nonuse ―― ○ -----
A3 Nonuse ―― ○ -----
A2 Mode switch IP
● The switch is used to select the “economic mode”, “dynamic
m ode” and “ snowla nd mode”. T he voltage is varia ble in
range of 0 V-2V .
A1 Nonuse ―― ○ -----
A30 Power supply PWR
● Power supply for TCU; is the main power source of drive
unit and solenoid valve.
A29 Nonuse ―― ○ -----
A28 1st-G ear indicator lamp
/1st-G ear position﹡ OP
● Drive the instrument panel indicator lamp indication, indicate
that the gear-position is in “1st-G ear”
A27 2nd-G ear indicator lamp
/2nd-G ear position OP
● Drive the instrument panel indicator lamp indication, indicate
that the gear-position is in “2nd-G ear”
A26 3rd-G ear indicator lamp
/3rd-Gear position﹡ OP
● Drive the instrument panel indicator lamp indication, indicate
that the gear-position is in “3rd-Gear”
A25 Automatic gear indicator
lamp /4th –Gear position OP
● Drive the instrument panel indicator lamp indication, indicate
that the gear-position is in “automatic-Gear”
Automatic transmission-48
s oleno id
valve Condition Transmission operation
1 Opened
always 1st-Gear replaces 2nd-Gear; 4th-Gear replaces 3rd-Gear. It causes the car form the G ear shift of 1
→1→4→4 when accelerate form static. The transmission stay longer time in Gear; worse 1→4
shift feeling.
Closed always 2nd-Gear replaces 1st-Gear; 3rd-Gear replaces 4th-Gear. It causes the car form the G ear shift of 2
→2→3→3 when accelerate form static. It is said that starts form 2nd-Gear.
2 Closed always 4th-Gear replaces 1st-Gear; 3rd-Gear replaces 2nd-Gear. It causes the car form the G ear shift of 2
→2→3→3 when accelerate form static. That is saying that start form 4th-Gear.
Opened
always 2nd-Gear replaces 3rd-Gear; 1st-Gear replace 4th-Gear.
It cause the car is shifted form 1st-Gear to 2nd-Gear, then from 2nd-G ear to Gear when accelerate
form static. It will feel the transmission is in free gear position after 2→1 Gear shift.
1&2 Opened
always Can not realize the reverse gear; only has 1st-Gear operation.
3 Closed always Following shifts are bad. (2→3 is worst ):1→3, 1→4, 2→3, 2→4, 4→2, 4→1
Opened
always Following gear shifts are worse: 3→4, 4→3, 3→2。
It may cause the gear slide when the hydraulic torque converter is locked.
4 Closed always Following gear shifts are worse:
1→2, 1→3, 1→4, 2→3, 2→4, 3→1, 3→2, (including manual) 3→4, 4→1, 4→3
Opened
always Following gear shifts are worse: (1→2 is worst) 2→4, 3→2 It may cause the gear slide when
the hydraulic torque converter is locked.
6 Closed always The line pressure is high always.
Opened
always The line pressure is low always. So it cause the slide between gears. The clutch C1 and brake belt
B1 will be burned.
7 Closed always The hydraulic torque converter is without lock.
Opened
always The hydraulic torque converter is locked in 3rd-Gear and 4th-Gear. It cause the car generates the
vibration in low-speed status.
Table 6.1.2 Operation of transmission when ON/OFF solenoid valve is faulty
Mechanical detection
1.Inspection of transmission on car
It should process the following detections before disassemble the transmission:
process the on-road drive test to determine the failure cause .(according to requirement)
Detect the standard of transmission fluid. (refer to 7.2.1)
Ensure the transmission fluid in not overheated. (Normal color and smell)
Detect the failure information.
Check the battery terminal and grounding for corrosion or loose.
The engine speed is within the specified value in manual.
Check the cooling system for normal operation.
All power supply and plug wires is tight and not loose.
Check the transmission fluid, ensure the oil pan is without other martial material or pollutant.
2. Oil leakage detection
It should wash the polluted part of the transmission before select the oil leakage part, then drive the car.
When detect the leakage part of the rear servo system, it should lift the car by lifter firstly, then switch the gear to reverse
gear within 10s.
When detect the leakage part of front servo system, it should lift the car by lifter firstly, then switch the gear to gear-2
(winter mode).
The time switched to 2nd-Gear should be no more than 10s to avoid the oil in the torque converter is overheated.
3. FAQ table
Automatic transmission-49
The distribution of FAQ table is shown as follows:
Table 6.2.1 Drive failure Table 6.2.3 Shift quality failure
Table 6.2.2 Shift mode failure Table 6.2.4 Disassembly failure
failure Possible reason Corresponding measure
“D”-Gear operation
has not drive The automatic transmission fluid is insufficient.
The oil-entering of C1/C2 piston is blocked.
The “Z” is assembled incorrectly.
The primary regulating valve plug is opened.
The overspeed shaft or input shaft sealing ring is
failure.
3→4, 1→2 single-way clut ch is installed in revers e or
failure. Check the liquid level. Fill it up if necessary.
Check and wash the C1/C2 oil inlet device.
Reinstall the “Z” connection.
Remove, wash and reinstall the primary
regulating valve.
Check and replace it if necessary.
Check and replace it if necessary.
The reverse shifting
operation is without
drive.
The manual 1
st-Gear
has not engine
brake.
The engine brake is
normal in manual
1
st-Gear. The input shaft oil seal ring is damaged.
The rear brake belt or servo system is faulty.
C3, C3 wheel shaft or C1/C2 cylinder are out of work. Check and replace it if necessary.
Test the servo system or replace the rear brake
belt according to the requirement.
Test the failure C3, C3 wheel axle or C1/C2
cylinder.
Repair it in time if necessary.
“D” –Gear and reverse
–Gear operation is
without drive. The primary regulating valve is blocked.
The pump gear is damaged.
Take out the output shaft clasp. Det ect and clean the primary regulating valve.
Check and replace the pump gear if necessary.
Check and repair it if necessary.
Only can 2→3 shifting
(can not realize the
4
th-Gear and 1st-Gear) S1 is closed always. Test the S1. Repair or replace it if necessary.
Test the failure of S1 12V power supply
voltage or wire bundle.
Only can 1→4 shifting
1→3→4 shifting (1
→2 shifting delay). S1 is opened always Test the S1. Repair or replace it if necessary.
Test the failure of S1 12V power supply
voltage or wire bundle.
Only can 4→3 shifting S2 is closed always.
Test the S2. Repair or replace it if necessary.
Test the failure of circuit break or wire bundle.
1→2→neutral position
shifting (1st-Gear
transition) S2 is opened always Test the S2. Repair or replace it if necessary.
Test the failure of circuit break or wire bundle.
Only can 1→3 shifting B1 is out of work
The brake belt is loose.
The front servo piston or oil s eal is out of work.
S1/S2 ball spool is reinstalled in wrong place. Test and adjust it according to the requirement.
Test and maintain it according to the
requirement. Test and replace or reinstall it according
to the requirement.
Only can 1→3→4
shifting The small O-ring of front s ervo piston is invalid or
lost.
2→3 Gear position shifting valve is blocked. Det ect the O-ring. Process the replacement or
reinstallation if necessary. Detect the 2→3
Gear shifting valve; Process the maintenance
or replacement according to the requirement.
Only can 1→2→1
shifting C1 is invalid or 3rd-Gear and 4th-Gear is loose. (give
to 1st-Gear in 3rd-gear; give to 2nd-Gear in 4th-Gear) Det ect the clutch C1. Repair or replace it if
necessary.
Can not realize the
man ual 4→3, 3→2, 2
→1 Overspeed clutch /ball spool has displacement.
C4 is invalid. Detect the ball spool. Process the replacement
or reinstallation according to the requirement.
Det ect the C4. Repair C4 or r eplace the C4
wave pan according to the necessary.