Procedure
1. Start the engine until the gearbox warms up to a temperature of 80–100°C.
2. Raise the front of the vehicle so that the drive wheels can turn freely.
3. Connect a special pressure gauge with an adapter to each pressure test nipple.
4. Measure the transmission fluid pressure at various selector lever positions and engine speeds shown in the table.
5. If the pressure does not correspond to the required values, check and repair the gearbox components.
Automatic transmission F4A42
State | Standard transmission fluid pressure, kPa | ||||
Selector positions | Selector lever position | Crankshaft speed, min⁻¹ | Pressure Reduction (UD) | Rear Clutch (REV) | Overdrive Clutch Pressure (OD) |
R | – | 2500 | – | – | – |
R | Z.h. | 2500 | – | 1,270–1,770 | – |
N | Neutral. | – | – | – | – |
D | 1st lane. | 2500 | 1,010–1,050 | – | – |
2nd lane. | 2500 | 1,010–1,050 | – | – | |
3rd lane. | 2500 | 780–800 | – | 780–880 | |
4th lane. | 2500 | – | – | 780–880 | |
Automatic transmission F4A42 (continuation)
Standard transmission fluid pressure, kPa | |||
| Low gear brakes and reverse gear (LR) | Brakes 2nd gear (2ND) | Clutch regulator pressure (DA) | Clutch Damper Regulator (DR) Pressure |
260–340 | – | – | 220–360 |
1,270–1,770 | – | – | 500–700 |
260–340 | – | – | 220–360 |
1,010–1,050 | – | – | 500–700 |
– | 1,010–1,050 | – | 500–700 |
– | – | More than 750 | 450–650 |
– | 780–880 | More than 750 | 450–650 |
Transmission Fluid Pressure Test Results Analysis (F4A42)
Sign of malfunction | Possible cause |
| All hydraulic pressures are high | The transmission control cable is incorrectly adjusted |
| The control valve is faulty | |
| All hydraulic pressures are low | The transmission control cable is incorrectly adjusted |
| The oil pump is faulty | |
| The internal oil filter is dirty | |
| The oil radiator is blocked | |
| The control valve is faulty | |
| The safety valve is faulty | |
| The valve body is not installed correctly | |
| Hydraulic pressure is abnormal only in the selector position "R" | The control valve is faulty |
| The hole is blocked | |
| The valve body is not installed correctly | |
| Hydraulic pressure is abnormal only in selector position "3" or "4" | The control valve is faulty |
| The hole is blocked | |
| The valve body is not installed correctly | |
| Overdrive solenoid valve faulty | |
| Overdrive pressure control valve is faulty | |
| The commutator valve is faulty | |
| Hydraulic pressure is abnormal only in downshift gear | Oil seal K is damaged |
| Oil seal L is damaged | |
| Oil seal M is damaged | |
| Possible cause | |
| Downshift solenoid valve faulty | |
| The downshift pressure control valve is faulty | |
| The control ball is damaged | |
| The hole is blocked | |
| The valve body is not installed correctly | |
| Hydraulic pressure is abnormal only on the reverse clutch | Oil seal A is damaged |
| Oil seal B is damaged | |
| Oil seal C is damaged | |
| The hole is blocked | |
| The valve body is not installed correctly | |
| Hydraulic pressure is abnormal only on overdrive | Oil seal D is damaged |
| Oil seal E is damaged | |
| Oil seal F is damaged | |
| Overdrive solenoid valve faulty | |
| Overdrive pressure control valve is faulty | |
| The control ball is damaged | |
| The hole is blocked | |
| The valve body is not installed correctly | |
| Hydraulic pressure is abnormal only in low gears and reverse gear | Oil seal damaged I |
| Oil seal damaged J | |
| Low and Reverse Solenoid Valve Faulty | |
| Low and reverse gear pressure control valve is faulty | |
| The commutator valve is faulty | |
| Safety valve A is faulty | |
| The control ball is damaged | |
| The hole is blocked | |
| The valve body is not installed correctly | |
| Only secondary hydraulic pressure is abnormal | Oil seal G is damaged |
| Oil seal H is damaged | |
| Oil seal O is damaged | |
| Secondary solenoid valve is faulty | |
| The secondary pressure regulating valve is faulty | |
| The safety valve B is faulty | |
| The hole is blocked | |
| The valve body is not installed correctly | |
| Only the reverse clutch hydraulic pressure is abnormal | The oil radiator is damaged |
| Oil seal N is damaged | |
| Shock absorber clutch control solenoid valve is faulty | |
| The shock absorber clutch control valve is faulty | |
| The torque converter pressure control valve is faulty | |
| The hole is blocked | |
| Pressure is not applied to the operating element | The valve body is not installed correctly |
| The transmission control cable is incorrectly adjusted | |
| The valve is damaged | |
| The control ball is damaged |