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. 35 diagnostic trouble codes (DTCs) can be stored. A fault which is detected in the most recent operating cycle is defined as permanent. Other faults which are detected are defined as intermittent.

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.

Reading off extended diagnostic trouble code (DTC) information
This function can be used to read parameters, status identifiers and counters stored at the same time as a diagnostic trouble code (DTC). These are called frozen values.

For further information, see Frozen values steering wheel module, description.

Reading the control module identification
VADIS 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.

Downloading software and replacing the control module
New software can be downloaded into the steering wheel module (SWM). 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.

The control module is integrated in the steering wheel bracket. The steering wheel must be removed to replace the control module.