Take Volkswagen car for example, select Diagnosis, then select Europe Car, users can see Volkswagen’s logo. If the logo has not been seen,
Different vehicles have slight different menus.
Common main function menu includes the following options:
Read ECU:
This function is to read ECU version information, which is the equivalent of “System Identification” or “System Information” in some electronic
control systems, all mean to read ECU related software and hardware versions, models and production date of diesel engine, part number,
etc. It is convenient for us to make record in the maintenance process, and it also makes later date feedback and management easier.

Read DTCs:
read trouble codes stored in ECU.
Select Read Trouble Codes to read trouble codes stored in ECU. Screen will show the trouble code and its definition when read the
trouble codes,shown as below.

Tip: In the process of diagnosis, if the device shows “System is OK” or “No Trouble Code”, it means there is no related trouble code
stored in ECU or some troubles are not under the control of ECU, most of these troubles are mechanical system troubles or executive
circuit troubles, it is also possible that signal of the sensor may bias within limits, which can be judged in Live Data.
Clear DTCs:
Return to the previous step, select Clear DTCs to clear current and historical trouble codes memory in ECU. Performing this function will
clear all thecurrent and historical trouble codes. Make sure whether the trouble codes have been recorded before clearing, shown as below.

Click YES to make clear confirmation, if the communication is normal, it will show “Trouble Codes Successfully Cleared” or “Trouble Codes Cleared”. Generally, users need re-read trouble codes after cleaning them to confirm whether the trouble codes have been cleared.
Suggestion:
users should better not to clear trouble codes, we need record the trouble details after reading code, which is provided as reference for maintenance.
After dealing with troubles, there will be no trouble code when we re-read.
Read Live Data:
that is to read the parameters of running engine, such as oil pressure, temperature, engine speed, fuel oil temperature, coolant temperature,
intake air temperature, etc. Based on these parameters, we can judge directly where the problem lies, which helps to narrow the scope
in maintenance. For some vehicles, during their actual operation, the problems such as performance characteristics offset, sensitivity reduction,
can be judged in live data. This function needs us very familiar with engine parameters, for instance, when idle speed is 800RPM or 750RPM,
coolant operating temperature is between 80~105℃, what are the operating voltage and time of each sensor and actuator?
