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.
Should a fault disappear for any reason after being permanently stored in the control module as a diagnostic trouble code (DTC), the information remains stored in the control module.
If a fault is no longer permanent, the diagnostic trouble code (DTC) remains as intermittent.

Reading and erasing diagnostic trouble codes (DTCs)
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.

Note! Certain functions are unavailable until the diagnostic trouble codes (DTCs) have been erased.

Reading off the control module identification
VIDA 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.
For further information about the MD Module (MP1), see Description of vehicle communication information Vehicle Communication Information, MD Module (MP1).
For further information about the CD Module (MP2), see Description of vehicle communication information Vehicle Communication Information, CD Module (MP2).

Reading off the parameters
Using this function, the status or value of parameters can be read off. The status/value can be presented digitally. For further information about the different parameters, for the MD Module (MP1) see Description of parameters Description of Parameters and for the CD Module (MP2) see Description of parameters Description of Parameters.