Order of execution
1. Start the engine until the transmission 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 dedicated pressure gauge with adapter to each pressure test port.
4. Measure the pressure of the transmission fluid at various positions of the selector lever and the engine speed given in the table.
5. If the pressure does not meet the required values, check and repair the gearbox elements.
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.x. | 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 Z.H. (LR) | Brakes 2nd gear (2ND) | Clutch Regulator Pressure (DA) | Clutch damper regulator pressure (DR) |
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 |
– | – | Over 750 | 450–650 |
– | 780–880 | Over 750 | 450–650 |
Analysis of Transmission Fluid Pressure Test Results (F4A42)
Symptom | Possible reason |
All hydraulic pressures are high | Transmission control cable incorrectly adjusted |
Defective control valve | |
All hydraulic pressures are low | Transmission control cable incorrectly adjusted |
Faulty oil pump | |
Dirty internal oil filter | |
Oil cooler blocked | |
Defective control valve | |
Safety valve defective | |
Valve body incorrectly installed | |
Hydraulic pressure abnormal only in selector position «R» | Defective control valve |
Hole blocked | |
Valve body incorrectly installed | |
Hydraulic pressure abnormal only in selector position «3» or «4» | Defective control valve |
Hole blocked | |
Valve body incorrectly installed | |
Faulty overdrive solenoid valve | |
Faulty overdrive pressure control valve | |
Switch valve defective | |
Hydraulic pressure abnormal only in downshift | Damaged oil seal K |
Damaged oil seal L | |
Damaged oil seal M | |
Possible reason | |
Downshift solenoid valve defective | |
Downshift pressure control valve defective | |
Control ball damaged | |
Hole blocked | |
Valve body incorrectly installed | |
Hydraulic pressure abnormal only on reverse gear clutch | Damaged oil seal A |
Damaged oil seal B | |
Damaged oil seal C | |
Hole blocked | |
Valve body incorrectly installed | |
Hydraulic pressure abnormal only in overdrive | Damaged oil seal D |
Damaged oil seal E | |
Damaged oil seal F | |
Faulty overdrive solenoid valve | |
Faulty overdrive pressure control valve | |
Control ball damaged | |
Hole blocked | |
Valve body incorrectly installed | |
Hydraulic pressure is abnormal only in low and reverse gears | Damaged oil seal I |
Damaged oil seal J | |
Faulty low and reverse solenoid valve | |
Faulty pressure control valve for low gears and reverse gear | |
Switch valve defective | |
Relief valve A defective | |
Control ball damaged | |
Hole blocked | |
Valve body incorrectly installed | |
Only secondary hydraulic pressure is abnormal | Damaged oil seal G |
Damaged oil seal H | |
Damaged oil seal O | |
Faulty secondary solenoid valve | |
Defective secondary pressure control valve | |
Safety valve B defective | |
Hole blocked | |
Valve body incorrectly installed | |
Only reverse clutch hydraulic pressure is abnormal | Damaged oil cooler |
Damaged oil seal N | |
Faulty shock absorber clutch control solenoid valve | |
Faulty shock absorber clutch control valve | |
Defective torque converter pressure control valve | |
Hole blocked | |
Pressure is applied to a non-functioning element | Valve body incorrectly installed |
Transmission control cable incorrectly adjusted | |
Valve damaged | |
Control ball damaged |