Automatic gearbox diagnostics

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:

1. Pre-check;
2. Tire pressure check;
3. Check the automatic transmission fluid level;
4. Checking the idle speed;
5. Checking the throttle cable and throttle control cable;
6. Checking the control rod of the automatic transmission;
7. Checking the engine start inhibit switch.
8. Checking for Trouble Codes (for automatic transmission with electronic control system).
9. Check how the gear shifting and the working of an electrical control system.
10. Check the gearbox with the car stopped.
11. Do a road test. Pay attention to noises, and vibrations, which may indicate an exact malfunction of the car.
12. Check the pressure into the main line and the pressure of the speed controller (for automatic transmission with a hydraulic control system).
13. Check the transmission shift time. Check the wear of the gearbox parts (clutches, brakes and planetary gears).