Clearing Trouble Codes

Transmission control module (TCM) diagnostic functions
General





The control module has a built-in diagnostic system, the Volvo on-board diagnostic (OBD) system. This system continuously monitors its own system and the input and output signals.

Diagnostic trouble codes (DTCs)
The control module will store a diagnostic trouble code (DTC) if it 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 when all diagnostic trouble codes (DTCs) have been read at least once.

Reading off input and output signals
Using this function, the status of the control module input and output signals can be continuously read off.
For further information about parameters, see Description of parameters

Activating components
This function allows components to be activated so that their functions can be checked.
For further information about activations, see Description of activations

Reading off the control module identification
VADIS identifies the control modules by reading off a number of codes from the control module memory.
The codes contain the following information about the control module:
- the hardware P/N (control modules without software)
- the hardware serial number (control modules without software)
- the software P/N
- the diagnostic software P/N

Downloading software and replacing the control module
New software can be downloaded into the transmission control module (TCM). When ordering software, the hardware and the software in the car is compared to the data in the Volvo central database. If the comparison is OK the software is downloaded to the control module. If the comparison between the car and Volvo central database is not OK, the database is updated with the car configuration. When this is complete the software is downloaded.
For further information regarding downloading, see Design and Function, Downloading Software.