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.
There are two diagnostic trouble codes (DTCs) for the Accessory USB unit (AUU). A fault that was detected during the last driving cycle is defined as permanent. Other faults that are detected are defined as intermittent.

Reading out and erasing diagnostic trouble codes
Stored diagnostic trouble codes (DTCs) can be read off and erased using this function. Diagnostic trouble codes (DTCs) can only be erased once all the diagnostic trouble codes (DTCs) have been read off at least once.

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 out parameters, identify status and counts stored at the same time as a diagnostic trouble code (known as frozen values).
For more information, see Vehicle communication information in Specifications, other.