Intermittent bus faults
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 Trionic T7 and TCM continuously check that all control modules supplying them with information communicate correctly. Intermittent faults in bus communication with any of these systems will cause diagnostic trouble codes to be generated in the Trionic T7 and TCM. The fault could be caused by the control module in question having lost its power supply or one of the bus leads.
In the event of intermittent bus faults the diagnostic trouble code text will refer to a fault diagnosis described in the "BUS AND DIAGNOSTICS COMMUNICATION .