2006 GREAT WALL HOVER Service Repair Manual

Automatic transmission-13
Symbol of solenoid valve (On/off solenoid valve)
Figure 3.5 Normal-opened type
1.Variable pressure regulating valve regulating system
The shifting pressure of abrasion unit is controlled by the variable pressure regulating valve.
The line pressure is independent of the shifting pressure and determined by the thro
position, shifting status and engine speed.
S5 is a proportional or variable pressure regulating valve which provides the pressure signal control shifting pressure for
the clutch and brake belt regulating valve.
In automatic shifting period, it process the integral times enlarging and contracting
regulation for the clutch regulating valve, brake belt regulating valve, torque converter regulating valve and VPS.
The hydraulic pressure generated by variable pressure regulating valve is in inverse ratio with current. During the shifting, TCU
will increase or decrease the current of solenoid valve according to the program. The current is variable in the range of 200mA
to 1000mA. The increasing of the current will decrease the S5 output pressure; the decreasing of current will increase the output
pressure of S5.
Lin 500 pressure (about 440 to 560kPa) is the reference pressure of VPS, meanwhile, the VPS output pressure equals to the
pressure on line 500 always.
When the VPS is in waiting status, it means there is not the generation of shifting action. VPS current is 200mA. At this time,
it gives the maximum output pressure.
In stable status, the brake belt and clutch regulating solenoid valve is in closed status. In this condition, the pressure of line 500
is applied on the piston. For the line 500 pressure is more than S5 pressure always, so it pushed the oil in S5 to the place
between the regulating valve and piston. At this time, oil pressure applied on the friction unit equals to the product of pressure
on line 500 and magnification factor.
During the starting of shifting, the used on/off solenoid valve is in opened status which cut off the oil loop supply from line 500
to piston.
At the same time, VPS pressure is decreased to starting pressure valve, pressure set by regulating valve and pressure setting
value required by execution of VPS by pushing the piston from the valve. The shifting is finished through the on/off solenoid
valve, VPS returns to the waiting status
Pointed to each gear-position, the system can make the brake belt; clutch or both realize
the electronic control.
Mode indicator lamp: the mode indicator lamp can be used to indicate the current selected and whether the overpeed status
exists. The mode indicator lamp is located in instrument panel generally. (Refer to Part 2.3)

Automatic transmission-14
The main box includes:
z BIR blow-off valve
1. Valve
Figure 3.7 shows the valve unit in the view of transmission fluid tank. Figure 3.8 illustrates the pump cover.
2. Manual-operated valve
The manual-operated valve (refer to Figure 3.9) is connected to the car gear selection mechanism. It controls the transmission
fluid flow to the forward or reverse loop. Except in manual 1st-Gear position, the function of manual-operated valve is same
in all forward gear. In manual 1st-Gear, the transmission fluid will enter into the shift valve 1
2 to make the rear brake belt
and C4 overspeed gear clutch is engaged respectively. The hydraulic control system is located in the valve, pump and main box.
The valve includes the following types:
zManual-operated valve
z Three shift valves
zsequence valve
z electromagnetic pressure control valve
zline pressure control valve
zclutch connection regulating valve
zbrake belt connection regulating valve
zsolenoid valve 1 to solenoid valve 6
zreverse lock valve
The pump includes the following types:
zprimary regulating valve (control line pressure)
ztorque converter clutch regulating valve
ztorque converter clutch control valve
z
solenoid valve 7 Hydraulic control system

Automatic transmission-15
Figure 3.6Hydraulic control circulation flow

Automatic transmission-16
Figure 3.9 manual-operated valve 3.
1-2 shift valve (refer to Figure 3.10) has two position status. It must be in the position (2, 3, 4) for the convenience of raising
gear in 1
st-Gear. It is using for all 1-2 and 2-1 shift.
Through the power supply of S1 and (or ) S2, the 1-2 shift valve can acquire its On/Off status.
During 1-2 shift period, drive the transmission fluid from manual-operated valve to the 2
nd-Gear loop. During the shifting form
2 to 1, the brake belt is engaged and drain the oil through the 1-2 Gear shift valve.
When in 1
st-gear position, the 1-2 gear shift valve operates with the 3-4gear shift valve (described as follows) combinedly to
separate the clutch C4; if in 2
nd-Gear position, engage the clutch C4. When select the manual Gear-1, the clutch C4 engages with
the rear brake belt (B2).
31-2 shift valve

Automatic transmission-17
Figure 3.10 1-2 gear shift valve
Clutch combination regulating valve (refer to Figure 3.15) is a constant ratio regulating valve which provide the regulating pressure
of clutch C1 to control the change ratio of shifting quality clutch status. The ratio is about 2.25:1.
When the S3 is opened, the oil of 3
rd-Gear is provided to the valve and adjust the pressure (CAF) to 2.25 times of S5 signal
pressure. When S3 is in closed status, the output pressure is 2.25 times of pressure of line 500.
9. Clutch combination regulating valve

Automatic transmission-18
Figure 3.11 2-3gear shift valve
Figure 3.12 3-4gear shift valve
Figure 3.13 4-3sequence valve
Figure 3.14 Electromagnetic pressure regulating valve and line pressure impelling valve

Automatic transmission-19
Figure 3.15 clutch combination regulating valve
10. Brake belt combination regulating valve
aP-Gear or N-Gear, vehicle speed 3km/h
b
R-Gear , speed 10km/h
c
Speed of engine : 1250rpm
d
Diesel vehicle , Opening degree of throttle position: 25
eGasoline vehicle, opening degree of throttle position: 12
In this condition, the TCU control solenoid valve S1 and S2 are closed. The reverse lock valve is affected by the pressure form
S1-S2 transmission fluid; connect the line pressure to loop B2. The transmission fluid flows to servo internal and external
attachment area, the B2 is engaged.
When none of above condition is met, TCU control the solenoid valve S1 and S2 to be opened. The pressure of S1-S2 is
released and the spring control valve body is in locking status at the same. In this condition, the B2 attachment is prohibited.
The feature can realize the protection for transmission by controlling the B2 in high speed and providing the reverse-gear
locking.
If the transmission is in failure mode, then the rear brake belt will be attached in P-Gear, R-Gear and N-Gear.
Figure 3.16 brake belt combination regulating valve

Automatic transmission-20
Figure 3.17 reverse lock valve
12. Primary regulating valve
Primary regulating valve (PRV) (refer to Figure 3.18) can regulate the line pressure of transmission (or pump output
pressure). The valve can give the high or low line pressure according to the on/off status of S6. When S6 is in on or off status,
the pressure S6 is applied on PRV, move it and has the action of spring force. Open the line pressure loop to turn on the inlet
of pump to reduce the line pressure. Generally, the line pressure is small when the throttle position is opened lightly and in
patrol status. It will cause the closing of S6 when the opening degree of throttle position is large and because the high line
pressure valve
For all shifting pressures are controlled by output of separation brake belt , clutch regulating valve and S5, so all step control
of line pressure has not affect on effect of shifting sensing.
By the oil inlet of torque converter, PRV also adjust the oil supply of hydraulic torque converter. The level effect of PRV
should ensure the priority of valve, i.e. it can keep the line pressure in low engine speed condition. When the speed of engine
is increased and the pump supplies excess oil, the PRV acts to open the torque converter oil inlet cover to increase the pressure
of torque converter. If the oil amount is beyond the requirement of transmission, PRV will act further to allow the oil return
to the suction inlet.
Figure 3.18 Primary regulating valve
Figure 3.19 Torque converter on/off regulating valve
The torque converter regulating valve (refer to Figure 3.19) adjusts the pressure applied on torque converter clutch oil.
According to the signal pressure form loop S5, adjust the oil flow status from line pressure loop in valve. With the change of
pressure signal of loop S5, the engagement and disengagement of torque converter clutch can be finished by electric control.
13. Torque converter on/off regulating valve