Automatic gearbox diagnostics – is a complex of measures that determines the exact cause of the malfunction of the automatic transmission. As a rule, diagnostics start from the simplest operations with increasing complexity. It is important to determine the area of occurrence of a malfunction correctly because breakdowns can occur not only in the gearbox itself but also in its control system. Some malfunctions related to the engine.
When should I need to Diagnose a Transmission?
The next symptoms say that you need check the transmission: grinding or shaking sensation in gear, a car doesn’t respond when in gear, car makes noises, smells like its burning, gears slipping, leaking transmission fluid.
Gearbox diagnostic process
There are 7 Steps in the Diagnosis of an Automatic Gearbox:
- Tire pressure check;
- Check the automatic transmission fluid level;
- Checking the idle speed;
- Checking the throttle cable and throttle control cable;
- Checking the control rod of the automatic transmission;
- Checking the engine start inhibit switch.
- Checking for Trouble Codes (for automatic transmission with electronic control system).
- Check how the gear shifting and the working of an electrical control system.
- Check the gearbox with the car stopped.
- Do a road test. Pay attention to noises, and vibrations, which may indicate an exact malfunction of the car.
- Check the pressure into the main line and the pressure of the speed controller (for automatic transmission with a hydraulic control system).
- Check the transmission shift time. Check the wear of the gearbox parts (clutches, brakes and planetary gears).