Diagnostic Functions

Diagnostic Functions

General

Model year 1999-2002







The on-board diagnostic (OBD) system for the SRS continually diagnoses the function of SRS system components and stores any diagnostic trouble codes (DTCs). However, the diagnostics for the two front seat belt buckles are carried out by the central electronic module (CEM) which also stores any diagnostic trouble codes (DTC) for them. If a fault is registered for longer than 5 minutes, the central electronic module (CEM) transmits the diagnostic trouble code (DTC) to the supplemental restraint system module (SRS). The supplemental restraint system module (SRS) then stores diagnostic trouble code(s) (DTC) for the front seat belt buckles. The diagnostic trouble codes (DTCs) can then be read off via VADIS. The principle behind VADIS information presentation is the same as for other on-board diagnostic (OBD) systems.

Model year 2003-
The on-board diagnostic (OBD) system for the SRS continually diagnoses the function of SRS system components and stores any diagnostic trouble codes (DTCs). The diagnostic trouble codes (DTCs) can then be read off via VADIS. The principle behind VADIS information presentation is the same as for other on-board diagnostic (OBD) systems. The front seat belts are directly connected to the supplemental restraint system module (SRS).

Fault indication
The driver is warned in a number of ways via the combined instrument panel if any fault occurs in the SRS system:
- SRS warning lamp and text in the display
- The general warning lamp lights up in red and there is text in the display
- The orange general warning lamp and text in the display.

A VADIS station must be connected to the car data link connector (DLC) in order for a fault source to be identified.

Diagnostic trouble codes (DTCs)
The control module will store a diagnostic trouble code (DTC) if it detects a fault. The control module can store up to 10 diagnostic trouble codes (DTCs).

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 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.

After the diagnostic trouble code (DTC) is stored it can also be read off if the fault is still present (permanent fault), or if the fault has disappeared for any reason (intermittent fault).

Diagnostic trouble codes (DTCs) can only be erased when all diagnostic trouble codes (DTCs) have been read at least once.

Data read-out
Data can be read off with this function.

Car model
Read off the model that is programmed into the supplemental restraint system module (SRS), e.g. S80.

Steering
Read off whether the supplemental restraint system module (SRS) is programmed for left or right-hand drive.

Passenger airbag
Read off the configuration that is programmed into the supplemental restraint system module (SRS), with or without passenger airbag.

Seatbelt buckle front (model year 2003-)
Reads off the status of the driver and passenger seatbelt buckles.

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 information about the control module's:
- hardware P/N (control modules without software)
- hardware serial number (control modules without software)
- side impact sensor serial number
- software P/N
- P/N diagnostic software.