2006 GREAT WALL HOVER transmission

Automatic transmission-2
Instruction for automatic transmission
1. M88 4-speed automatic transmission is equipped with the hydraulic torque converter and electric control system with locking.
When keep the stable forward status, the hydraulic torque converter can be locked automatically when the engine operates in low
speed, then reduce the unnecessary slide.
Figure 1.1 Electric automatic transmission control system
Figure 1.2 M88 4 speeds automatic transmission appearance figure (applied to 2 wheels driving)
2. The main advantage of the transmission is the application of transmission control unit (TCU). The control unit is the control
system based on the microprocessor system.. TCU control the shifting sensing and realize the Gear position shifting through the
signal of opening degree of throttle position, opening frequency of throttle position, engine speed, vehicle speed, transmission oil
temperature, gear position, mode selection and forced Gear reduction application.
3. TCU drives a variable pressure regulating solenoid valve to control three regulation valves and control the feeling of shifting.
Different transmission fluid temperatures are taken as one the main parameters to control the output pressure of the solenoid
valve, so as to keep consistent feeling of shifting within the normal operation scope.
4. The planning of shifting is very flexible. According to the car model, the different shifting plan is stored in the same TCU.
Generally speaking, the “economical mode” can increase the economical efficiency of the fuel and the driving performance of the
car to the maximum limit. The “dynamic mode” can bring into full play the drive performance of the car to the maximum limit. The
“winter mode” can make the car starting from shift 2.

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8. Use two bolts to install the back device on the extended case of the transmission, these lengths are important. If it is too long,
it will hinder the end of the bolt and affect the threads on the case. Ensure the proper length and special torque of the bolt.
9. Pay attention that the height of the oil has been determined before delivery from the ION Company. The oil height needs not
checking or correction, except that improper oil is suspected to be used, or additional oil is needed because of leakage.

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10. The gross weight of the transmission is 76kg; mostly weight is on the front of the transmission (side of torque converter). This
should be considered when design the handling/assembly tools.
11. The crankshaft speed/position sensor is installed on the top of transmission torque converter housing which must be installed
after the transmission is installed on the engine. The sensor will be damaged if it is installed before the installation of
transmission.
12. The transmission use the breathing tube connected to rear end of transmission. The tube must not be restricted or blocked
otherwise the air pressure in transmission will be increased. It is unallowable that the water/dirty/dust enters into the
breathing tube; otherwise the transmission will be damaged.
Removal of transmission
If the transmission needs removing for any reasons, following is the preventive measure to help the remove.
1. Must not only support the oil pan in middle of transmission for it will be deformed and leaked. The oil pan will not be deformed
when supports its external edge.
2. It must not allow the transmission to connect to the engine when the rear end is without connection, otherwise the exhaust
system of vehicle will be damaged.
3. Remove all torque converter bolts and push back the torque converter before remove the bolt connected the torque converter
housing to engine. Once all bolts connected the torque converter housing to engine are removed, use the torque converter the
push the transmission from the location pin, then ensure the torque converter is on the transmission and the transmission is
separated form location pin.
4. Install the dustproof cover on the cooler connector rapidly after open the oil cooler pipe; otherwise the oil leakage from the
torque converter will be 2L. The odometer dustproof cover can prevent the dirty from entering into the transmission and avoids
the leakage of oil form transmission.
5. The engine speed sensor is installed on the top of transmission and should be removed before the transmission is removed form
the engine, for the sensor will be damaged during the removal process of the transmission.
Figure 2.1 Gear selection interface
mode selection
gear selection
indicationgear slide way
Operation and display interface
The four-speed automatic transmission has three types of operation display interface which are shown as follows:
Gear selection
The transmission uses the traditional gear selection shifting handle, which is shown in figure. The gear rod can be moved on the gear
slide way according to the requirement. The relationship between the related gear and its function.

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Table 2.1 Gear selection and its function
Gear selection function
1st-Gear
(manual 1
st-Gear ) The first gear is using for climbing and braking. It is a function which limits the speed of
the car. The speed limitation by engine is realized by reduce the opening degree of
throttle position.
2nd-Gear (automatic, manual
2
nd-Gear) In economic mode, it can process the 1
st and 2nd shifting operation when engage the 2nd
–Gear. The limitation of vehicle speed by engine is realized through reducing the
opening of throttle position. in 4WD 4 high, , the transmission will maintain 2
nd-Gear
position The manual mode and winter-Mode will only maintain 2nd-Gear 。
3rd-Gear
(automatic, manual 3rd-Gea) In economic mode and dynamic mode, it can process the shifting operation of 1
st, 2nd
and 3rd-Gear when engage the 3rd-Gear, and can reaches the very high vehicle speed. At
this time the locking clutch can process the locking action, refer to vehicle user manual.
The limitation of vehicle speed by engine is realized by reduce the opening of throttle
position. In 4WD 4 low, the transmission should be maintained in 3
rd –Gear position.
Under manual mode, the transmission will be kept in 3rd-Gear.
D-gear
(drive) It can process the 1
st, 2nd, 3rd and 4th –Gear position operation and gear-shifting operation
of (1-2), (1-3), (2-3), (2-4), (3-4), (4-3), (4-2), (3-1) and (2-1). This shifting operation is
processed by taking the vehicle speed, throttle position, throttle position switching
frequency (or forced Gear-decreasing) as the parameter. The locking clutch can process
the locking action in 3rd –Gear, 4
th-Gear according to the type of vehicle. Refer to user
manual of vehicle.
N-Gear
(neutral gear) Only the rear brake belt is engaged at this time. It determines whether the function can
be realized according to the vehicle speed, engine speed and throttle position. But the
gear-position sensor allows the starting of engine. Allow the slide of N-Gear.
R-Gear
(reverse gear) Set the anti-misoperation in forward function according to the vehicle speed, engine
speed and throttle position opening to realize the reverse operation. The gear-position
sensor can start the revers e lamp.
P-gear
(parking gear) Only the rear brake belt is engaged at this time. The function can be determined
according to the vehicle speed, engine speed and throttle position. The output shaft of
transmission is locked. The gear-position sensor can start the engine.

Automatic transmission-6
Selection of drive mode
The selection of drive mode includes a mode selection switch and indicator lamp. The drive mode selection switch is located
on the operating panel. It can provide the different mode selection according to the different type of car.
It has the optimal fuel economy when select the “normal” mode. At this time, the indicator lamp is not light. When select the
“dynamic” mode, the car will have the maximum dynamic performance and the “dynamic” mode indicator lamp is light. When select
the “snowland” mode, it will realize the starting of “2
nd-Gear”, the “snowland” mode indicator lamp is light, meanwhile the
“dynamic” mode indicator lamp will be closed. When select the manual mode, press down the “snowland” switch firstly, the
“manual” light will be light when the gear is in 3, 2, 1. When in manual mode, 1-2, 2-3, 3-4, 3-2, 2-1, 1-3, 3-1 is shifted by driver
manually and can not be shifted automatically. It can be used in car-racing etc. for the special mode of each model of car refers to
operation manual of user.
Operation instruction
Function
5 Brake function
Can decrease the gear-position in slope to improve the brake effect and increase the vehicle safety.
6 Speed-up function
It can select the manual shifting to increase the vehicle speed completely during the speed-up.
cautions
7 It must place the transmission in the P-Gear or N-Gear when start the engine.
8 It must place the transmission in P-Gear during the parking.
9 It must place the transmission in N-Gear when trail the car.
10 It must be powered off when remove the transmission.
11 It must be powered off when install the transmission.
The transmission processes the communication and calculation with the engine electronic control computer by the precision
central on-line computer. It not only save the fuel, but also provide the maximum mode function, including field, winter and
manual selection. It provides the two conditions, manual and electric for the fast race of racing player. It has racing capacity wh i ch
can compete the speed increasing with the manual transmission.
automatic
Having anti-slide function
It is allowable that the D-Gear
in “W” mode is used in
snowland and M-A integration
mode. automatic
automatic

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Indicator lamp
Figure 2.2
control system
General
The transmission has two sets of control system, a electric control system and a hydraulic control system. The electric control
system monitors the vehicle parameter and adjusts the transmission performance; the hydraulic control system executes the
command of electric control system.
Electric control system
The electric control system consists of the sensor, TCU and 7 solenoid valves. TCU read in the data and make the output under the
control of software based on the value stored in Read Only Memory (ROM).
TCU controls the hydraulic control system and the control is realized through the valve and pump assembly. The system includes
7 solenoid valves, in which 6 valves are used to control the line pressure, operate the shift valve and hydraulic torque converter lock
clutch and switch on and off two regulating valves (Two regulating valves control the shift feel). The seventh solenoid valve is the
pressure regulating solenoid valve (VPS) which controls the shift feel with other three regulating valves. Figure 3.1 is the typical TCU
control system plan.
The figure includes all elements of electric control system involved in the section.
throttle position
open sensor
Engine speed
vehicle speed
Transmission
fluid temperature
mode selection
(instrument panel
/console )
Gear sensor
Forced step-
decreasingK line
shifting
logic
shifting
sensing
line
pressurehydraulic
control
system
Solenoid valve 1
Solenoid valve 2
Solenoid valve 3
Solenoid valve 4
Solenoid valve 5
Solenoid valve 6
Solenoid valve 7
pressure regulating
solenoid valve
Mode indicator lamp
Gear indicator lamp
set and other
necessary equipment
indication

Automatic transmission-8

Automatic transmission-9
Table 3.1 Feature parameter of temperature /resistance
-2013,638
5,177
2,278
177
7517,287
6,616
2,723
196
85


Figure 3.2 Pin number of temperature /resistance
Pin No. Wire color Connected solenoid valve
1 Red solenoid valve 1
2 Blue solenoid valve 2
3 yellow solenoid valve 3
4 orange solenoid valve 4
5 green solenoid valve 5
6 violet solenoid valve 6
7 brown solenoid valve 7
8 green solenoid valve 5
9 white temperature sensor
10 white temperature sensor
ohm
Temperature
Centigrade degree