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)
If the control module detects a fault, a diagnostic trouble code (DTC) is set. Any fault detected during the last run cycle is defined as permanent. Other faults are defined as intermittent. A run cycle comprises ignition on, the car speed exceeding 10 km/h (20 km/h in XC90 with B8444S engine) and ignition off.

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.

Reading off input and output signals
This function can be used to continuously read off the status of the control module's input and output signals.

Activating components
This function can be used to activate components to check that they are working.

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 the following 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 (part of the software).