Brief description, TC/ABS 5.3: Diagnostics
WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
The control module continuously monitors its own internal functions and the other TCS components. A diagnostic trouble code is set if a fault develops. If only the TCS function is affected by the fault it will be disconnected and the TCS OFF warning lamp will light up. Since faults affecting the ABS function also affect the TCS function, the warning lamps for ABS, brakes, and TCS OFF will light up as well as the central warning lamp. The ABS and TCS functions are disengaged at the same time.