Parameter
For quick troubleshooting many of the vehicle systems provide digital measured values in the forms of parameters. Parameters indicate the current status or rather nominal and actual values of the component. The device displays the parameters alphanumerically and graphically.
Example
The engine temperature can be within a range of -30 °C to 120 °C.
If the temperature sensor reports 9 °C but the engine actually has a temperature of 80 °C, the ECU calculates an incorrect injection time.
A trouble code is not stored, as this temperature is logical for the ECU.
Fault text: Oxygen sensor signal faulty
In both cases, diagnostics can be significantly eased if the corresponding parameters are read out.
The mega macs S 20 reads the parameters and displays them in plain text. It additionally provides information on the parameters.