Description Of Frozen Values, Engine Control Module (ECM): Explanation

Frozen values are parameter values that are stored when a diagnostic trouble code (DTC) is stored.

Not all parameters can be read off for all diagnostic trouble codes (DTCs). The parameter values can only be read off where they can provide more information about the prevailing circumstances when the diagnostic trouble code (DTC) was stored.

When the control module detects a fault and stores the DTC, a number of parameters and their current values are stored in the control module's memory. These can be useful for example to troubleshoot as they give a good insight into the current conditions of and around the vehicle on which the fault was detected

The parameters can be divided into global and local parameters. The global parameters are always saved, regardless of which control module has stored the DTC. The local parameters are control module unique parameters and the storing of local parameters therefore depends on which the control module has stored the DTC.

Frozen values are parameter values that are stored when a diagnostic trouble code (DTC) is stored.

Not all parameters can be read out for all diagnostic trouble codes. The parameter values can only be read if they can provide additional information on the prevailing conditions when the code was generated.