tallinn@hobenool.eu +372 5191 5001

The transmission is the most complex electromechanical device of a modern car, being significantly more complex than an engine. At the same time, the transmission is more difficult to diagnose because it has few sensors and transducers to make the vehicle’s transmission computer (TCU) perform a self diagnosis.

Fault codes are visible to the TCU if there are strong and measurable malfunctions (e.g. no gear change) in the transmission. As a rule, no cosmetic disturbances (e.g. gear change as a shock or the presence of a vibration) are recorded as an error code and TCU alarms are not displayed.

Thus, diagnostics based only on fault codes gives a false and incomplete overview of the operation of the vehicle’s transmission.

Transmission’s cosmetic disorders indicate transmission malfunctions and repair needs. The complexity is compounded by the fact that a similar symptom can be caused by several different errors, individually or in combination.

Determining the exact cause of the transmission malfunctions requires thorough and special transmission testing, test drive and diagnosis.

Special transmission diagnostic process

Our long-term professionals have developed the special transmission diagnostic process of the Hõbenool, which aims primarily to find out whether the transmission only needs maintenance or more thorough repair. Special transmission diagnostics detects particular transmission faults and malfunctions that are inputs to the repair work.

Diagnostics of an automatic transmission

The following parameters are tested and analyzed during the special diagnostics of the Hõbenool:

  • The analysis of the transmission’s (TCU) fault code
  • The analysis of the adaptation values
  • The assessment of the load-bearing capacity
  • The assessment of the clutch engagement quality
  • The assessment of the control unit quality
  • The assessment of the clutches of the torque converter