Diagnostic Functions

Diagnostic functions

General
The control modules have a built-in diagnostic system, Volvo Diagnostics, which continuously monitors its own system as well as the input and output signals.

Diagnostic trouble codes (DTC)
If the control module detects a fault then it stores a diagnostic trouble code (DTC). If a fault disappears for any reason after a diagnostic trouble code (DTC) has been permanently stored in the control module then the information on the diagnostic trouble code (DTC) remains in the control module.

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

Reading off input and output signals
The status for the control module input and output signals can be continuously read off using this function.
For more information about parameters, see Vehicle communication information in Specifications, other.

Activating components
Components can be activated for function checking using this function.
For more information on activations, see Vehicle communication information under Specifications, other.

Reading off the control module identification
The control module can be identified by means of reading off a number of codes.
The codes contain information about the control module in accordance with the following:
- 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 in the software for the Transmission Control Module (TCM) for adaptation which can be activated:
- Resetting adaptation. Must be performed after replacing an internal component or the whole transmission.
- Resetting the gauge for oil degradation.
- Adaptation of gear selector lever in neutral position.

Calibrating the gear position indicator
When checking or replacing the control module the gear position indicator must be calibrated so that the gear position indicator adopts the correct gear position.