Diagnostic Functions

Diagnostic functions

General
The control module has a built-in diagnostic system, Volvo Diagnostic, which continuously monitors internal functions as well as input and output signals.

Diagnostic trouble codes (DTCs)
A diagnostic trouble code (DTC) is stored if the control module detects a fault.
If a fault disappears for any reason after the diagnostic trouble code (DTC) has been permanently stored in the control module, information about the fault remains in the control module.

Reading and erasing diagnostic trouble codes (DTCs)
Using this, the stored Diagnostic trouble codes (DTCs) can be read off and erased. Diagnostic trouble codes (DTCs) can only be erased once they have been read off at least once.

Reading off input and output signals
This function can be used to continuously read off the values and status of the control module's input and output signals.
For more information, see Vehicle communication information in Specifications, other.

Reading off the control module identification
The diagnostic tool identifies control modules by reading off a number of codes from the control module memory.
The codes contain information about the control module:
- hardware P/N (control module without software)
- hardware serial number (control module without software)
- software P/N
- diagnostic software P/N.

Reading off extended fault-tracing information
This function can be used to read parameters, status identifiers and counters stored at the same time as a diagnostic trouble code (DTC). These are called frozen values.