Note: If it becomes necessary to tow a vehicle with a working transmission, only tow it forward (transmission in N), on four wheels, for a distance of not more than 100 km at a speed not exceeding 80 km/h. If the transmission is suspected to be faulty or if the vehicle needs to be towed a considerable distance (or at high speed), the vehicle must be towed on its rear wheels only.
1. The transmission unit includes a torque converter and two assemblies of epicyclic gears, which are hydraulically controlled by multi-plate clutches and brake bands. The final drive differential is similar to that described in Section 7A. Fluid temperature is controlled by an optional transmission fluid cooler mounted on the radiator.
2. Electrically controlled gear shifting activates the 3rd and 4th gear lock mechanism and provides multiple driving modes and sub-modes to be selected according to the road conditions and the driver's desire.
3. Gearshift timing is determined by the electronic control device (ECU) automatically, according to various sensors (transmission fluid temperature, input and output shaft torque, engine coolant temperature, throttle and valve positions, etc.) and varies depending on the selected driving mode (see illustration). The ECU is located behind the glove compartment or behind the driver's footwell side trim panel.
1.3 Electric system of automatic transmission control unit AF 14/20 - version with Motronic ignition/fuel injection system
1 Distributor
2 Transmission fluid temperature sensor
3 Starter lock
4 Connection of solenoid pressure control units
5 Input shaft rotation sensor
6 Output speed sensor
7 Speedometer drive wiring connection
8 Throttle position sensor
9 Motronic unit
10 automatic transmission ECUs
11 Sub mode button "Winter"
12 Sub mode button "Economy/Sport"
13 Downshift mechanism
14 Stop lamp switch
4. The ECU controls the transmission through four solenoid units that regulate fluid pressure, which allows or shifts (solenoid blocks 1 and 2), or control the operation of the transformer clutch (solenoid block 3), or match fluid pressure to throttle position (solenoid block 4).
5. The ECU also reduces the ignition timing during gear changes (to ensure switching accuracy) and turn off the air conditioner (where used), if its operation interferes with the operation of the system. In addition, the ECU has a self-diagnostic function that turns on a special warning lamp if a problem occurs in the system.
6. Driving mode "D" has the following submodes:
7. "Economical" - turns on automatically when the engine is started. When the ignition is switched on, the control lamp on the panel lights up, which then goes out. The submode uses all four gears, including overdrive 4th. Gear changes are performed at low engine speeds for maximum smoothness and economy.
8. "Sports" - activated by pressing a button "S" at the top of the gear selector (the control lamp on the panel will light up). Submode blocks (electrically) 4th gear. Gear shifting is carried out at higher engine speeds. To exit the submode, either press the button again, or turn the ignition off and on again, or activate the self-diagnosis system (on the run), or switch to submode "Winter".
9. Submode "Winter" (also known as "Ease of launch") is activated by pressing the button with the symbol located at the base of the gear selector lever.
This sub-mode locks 1st and 2nd gears so that the car can start smoothly (in 3rd gear) on a slippery road. Switch to submode "Economical" can be done in several ways: press the button again, move the gear lever to another position, turn the ignition off and on again, hold the accelerator pedal fully depressed for more than two seconds, activate the self-diagnosis system (on the run) or increase the speed to 80 km/h.
10. The transmission and its control unit is a very complex system, but if the transmission is operated correctly, it will last reliably and for a long time. Transmission repairs and overhauls cannot be done by most dealers, let alone car enthusiasts. However, the dealer can test the control unit's electrical system using Opel's specific diagnostic equipment. Therefore, this Chapter is limited to maintenance procedures that can be performed by a motorist. Overhaul, troubleshooting, or any repair work should only be entrusted to a suitably equipped Opel dealer.
11. Models equipped with the X20 XEV engine have a modified ECU. One of the changes is a downshift lock that prevents mode switching "D" into mode "3" at speeds above 194 km/h.
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