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 stored in the control module.

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.
For further information about parameters, see: Description of parameters, AW50/51 AWD, AW55-50/51SN Description Of Parameters

Activating components
This function can be used to activate components to check that they are working.
For further information about activations, see: Description of activations, AW50/51 AWD, AW55-50/51SN Description Of Activations

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.

Resetting the adaptation values
There are three functions for adaptation in the transmission control module (TCM) software which can be activated:
- Resetting the adaptation. This must be done after internal components or the entire transmission have been replaced
- Resetting the oil quality counter
- Adapting the gear selector in neutral.

Calibrating the gear-shift position sensor
When checking or replacing the control module, the gear-shift position sensor must be calibrated so that the gear-shift position sensor identifies the correct gear position.

Activating test mode
When this function is activated, the sensitivity of the software to criteria for storing diagnostic trouble codes (DTCs) is reduced. This helps the mechanic when testing the function of the transmission.