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. A fault which is detected in the most recent operating cycle is defined as permanent. Other faults are defined as intermittent. An operating cycle involves ignition on, the vehicle speed exceeding 20 km/h and the ignition being switched 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.
For more information about parameters, see Vehicle communication information in Specifications, other.

Activating components
This function can be used to activate components to check that they are working.
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 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 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.
- Calibration of gear selector in neutral position.
The gear position sensor must be calibrated after check or replacement of the control module to ensure the gear position sensor detects the correct gear selector position.