40/104 24.43  27.61 

50/122 16.60  18.54 

60/140 11.53  12.73 

70/158 8.161  8.916 

80/176 5.880  6.360 

90/194 4.306  4.614 

100/212 3.201  3.399 

110/230 2.392  2.562 

120/248 1.811  1.955 

130/266 1.388  1.510 

140/284 1.075  1.179 

150/302 0.843  0.930 

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3.5.2 Description and operation 

3.5.2.1 DSIAutomatic transmission overview 

The speed change gear has the following characteristics: 

• 

Six forward gears are provided. 

• 

A reverse gear is provided. 

• 

A hydraulic torque converter is provided and includes a lock clutch capable of carrying out sliding abrasion 
control. 

• 

Employ the electric gear shift and pressure control 

• 

A single planetary gear row is provided. 

• 

A double-planetary gear row is provided. 

• 

A hydraulic control brake belt and a multi-friction sheet type brake are provided. 

• 

Four multi-sheet wet clutches (clutches C1, C2 and C3 and brake B1) are provided. 

All hydraulic functions are controlled and managed by an electromagnetic valve: 

• 

Adjusting meshing 

• 

Adjusting shift mass 

• 

Selecting mode of shift curve 

• 

Adjust hydraulic torque converter 

This automatic transmission uses synthesized automatic transmission oil. To ensure the automatic transmission 
can normally operate within its service life, you must replace the automatic transmission oil per 60000km 
traveled. 

The engine power is transmitted to the automatic transmission through the hydraulic torque converter with the 
lock clutch. 

This automatic transmission provides gear shift among six forward gears and one reverse gear by means of the 
combination of one driving single-row planet wheel and one driven dual-row planet wheel and such type of gear 
structure is usually referred to as Lepelletire type gear assembly. 

DSIAutomatic transmission control by electrical, its control system composition as follow: 

• 

Input shaft and the output shaft speed sensor 

• 

Four switch electromagnetic valves and fix variable flow electromagnetic valve units 

• 

Hydraulic torque converter (TC) 

• 

Automatic transmission control module (TCU) 

• 

Internal embedded memory module (EMM) 

Operate the internal clutch of the transmission and the brake strap by controlling the flow direction and pressure 
of the automatic transmission fluid (ATF). The transmission control unit (TCU) can control all electronic 
components as well as the gear selection, shift pressure and trackslip of the hydraulic torque converter. 

If the transmission incurs the system fault, the transmission control unit (TCU) can also maintain maximized run 
of the function of the transmission through fault mode effect control (FMEC). If the transmission control unit 
(TCU) is completely out of control or powers off, the transmission still can retain its basic variable speed function 
(i.e., parking, reversing, and driving at neutral and fourth gear. The fourth forward gear, the reverse gear and the 
hydraulic torque converter clutch can be opened via the pure hydraulic system in the case without electronic 
control assistance completely. 

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The transmission also comprises an externally built gear (P, R, N and D) selector sensor (gear switch) and a 
built-in gear box oil temperature sensor. 

Under the application program of the manual mode, the transmission control unit (TCU) further needs to obtain 
the relevant signal from the transmission selector to determine the time that the driver stars the function of the 
manual mode. 

If the transmission is broken down seriously or the other parts of the whole vehicle are broken down affecting the 
normal operation of the transmission, the transmission control unit (TCU) can automatic operate the limp home 
(malfunction) mode, thereby ensuring the vehicle can travel to the authorized dealer for maintenance. In limp 
mode, the engine malfunction (MIL) indicator lamp on the dashboard will be controlled to turn on, and the 
transmission will continue to operate in the case of functional limitation. The limit grade of the function depends 
on the severity of the fault detected by the TCU. 

If the transmission overheats, the shift mode shall be automatically switched to the working condition that is 
conductive to the transmission cooling. 

In extremely high temperature environments, in order to protect the transmission hardware, the transmission 
control unit (TCU) would disable all the shift functions of the transmission, so that the transmission is in the 
neutral state, until the transmission oil temperature is cooled to a safe level. 

The transmission control unit (TCU) can also perform the transmission diagnosis and monitor all components that 
may affect the emissions from the vehicle. The diagnosis protocol complies with the requirements of the on-board 
diagnosis protocol II. In addition, the additional diagnostic function is supported to ensure all faults are quickly 
dismantled under the use environment. 

If the vehicle is broken down to tow, firstly dismantle the main driving axle or support the driving wheel off the 
ground, and then drag the vehicle. If not moving the main transmission shaft or dragging the vehicle after 
supporting the driving shaft, the transmission may be broken down due to insufficient lubrication of the 
transmission bearing. 

If the occurrence of the failure mode is sporadic, pull out the ignition key to withdraw limp home mode, and 
restart after 30 s; if the fault is still present, the transmission will still re-enter the limp home mode. where whether 
the failure mode will appear again, immediately slow down to the nearest service station for repairs. 

3.5.2.2 Six forward gear characteristic 

Emergency brake skip-level shift down function 

When the emergency brake is detected, the transmission can downshift with skid-level to increase the engine 
brake in order to avoid the gear from suffering from instantaneous excessive pressure. 

Uphill / downhill gear control 

If releasing the accelerator pedal during uphill, the normal upshift will be postponed, thereby reducing the 
frequent replacement of the gear to alleviate the sense of effort when climbing. If releasing the accelerator pedal 
during downhill, the normal upshift will be also postponed, thereby improving the engine brake. 

Forward gear and reverse gear 

When selecting forward gear or reversing gear, impact startup may be avoided from resulting in vehicle running 
forward through gentle clutch engagement performance. The process is realized by limiting the engine speed and 
torque. When the shift level is put into the position D or R immediately from Position P or Neutral, the time from 
starting gear shifting to completely combining the clutch is less than 2.2s. 

Note: the vehicle can be switched from gear D to gear N in the process of moving; if the speed is higher, put 
into the gear D from the gear N; in order to ensure the safety of the transmission and the vehicle, the 
transmission control unit (TCU) does not engage the gear immediately; when the following conditions are met, 
restore the corresponding gear to drive, with slight impact at the moment. For safety consideration, put the 
vehicle back to Gear D after stopping the vehicle completely. 

Combination condition-gear D:accelerator pedal opening is less than 20%; 

 

The engine speed is less than 2,000 rpm. 

Combination condition-gear R: 

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Accelerator pedal opening is less than 12%; 

 

The engine speed is less than 1,700 rpm; 

 

The vehicle speed is lower than 10km/h. 

The torque converter clutch can be locked under all gear conditions. 

This transmission can lock the torque converter clutch under all gear conditions. This function can save fuel and 
improve the vehicle performances. Further improve the transmission cooling efficiency when driving with large 
load at low speed, such as driving in city or mountain. 

Embedded memory module 

During the assembly of the transmission, the embedded memory module (EMM) is matched with the transmission 
valve body to ensure the precise shift quality. Embedded memory module (EMM) is installed on the transmission 
valve body. Embedded memory module (EMM) is used for storing data, such as valve body calibration data and 
valve body S/N data. 

Upon completion of the installation, the transmission control unit (TCU) will download data from the embedded 
memory module (EMM) and use such data when the transmission is in operation. 

3.5.2.3 Transmission cooling system 

The transmission cooling system ensures rapid warm-up and the transmission can operate at a constant 
temperature to reduce the fuel consumption and ensure the high shift quality. 

The transmission cooling system also comprises the cooler branch in the hydraulic system, so it can be ensured 
that a sufficient amount of coolant and lurbcant is conveyed to the transmission system of the transmission when 
the transmission cooler is blocked. 

Max.stall pressure (Max.flow is 6.5 lt/min with 90 )

℃

 

Max. 1.65 bar

 

3.5.2.4 Shift strategy 

Shift transformation 

Gear shifting of the transmission is controlled by the transmission control unit (TCU). The transmission control 
unit (TCU) receives different signals from all engine and vehicle sensors and select appropriate shift curves and 
controls the shifting quality and the action of the hydraulic toruqe converter clutch (TCC) in each shifting process. 

Sliding downshift 

Slide downshift occurs in the course of the vehicle sliding until stopping, the throttle pedal is completely released, 
so that the transmission automatically downshift in the free slide deceleration process of the vehicle. 

Torque demand 

When the torque needing for the driver is more than that provided by the engine under such transmission ratio, the 
transmission will open a hydraulic torque converter clutch (TCC) to provide extra torque output. 

Manual mode 

Differing from the Manual transmission, the manual mode of the automatic transmission includes certain 
automatic control factor in order to avoid high engine speed to damage the transmission. 

When the shift level is in the position M, the driver can define the applicable gear positions through + or - on the 
selector When initially moving the shift level to a manual M position, the transmission will select the minimum 
applicable gear position. 

Note: if the higher gear is selected under the condition that the vehicle speed is too low, or the lower gear is 
selected under the condition that the speed is too high, a shift operation shall not be executed with the 
consideration of the vehicle safety. 

If the engine speed or the vehicle speed is too low, the transmission will automatically downshift to maintain 
the minimum engine speed. The downshift process is the same as the automatic control of the gear D. 

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