Diagnostic Functions

TCM diagnostic functions

General




The control unit has built-in diagnostics, Volvo Diagnostics, which continually monitor the system and the input and output signals.

Diagnostic trouble codes
If the control unit detects a fault, it stores a diagnostic trouble code. If, for any reason, a fault disappears after the diagnostic trouble code has been permanently stored in the control unit, information about the trouble code still remains in the control unit.

Reading and erasing diagnostic trouble codes
Stored diagnostic trouble codes can be read and erased using this facility.
Erasing diagnostic trouble codes can only be done when all the diagnostic trouble codes have been read at least once.

Reading input and output signals
Status of control unit input and output signals can be continually read using this facility.
For more information about parameters, see Description of parameters Description of Parameters.

Activation of components
Using this facility, components can be activated to check their function.
For more information about activations, see Description of activations Description of Activations.

Reading the control unit identification
VIDA identifies control units by reading the number of codes from the control unit memory.
The codes contain information on the control unit as follows:
- hardware component number (control unit without software)
- hardware series number (control unit without software)
- software component number
- diagnostic software component number