Diagnostic procedure
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.
There is communication on the VR-bus as long as there is +54-current. This DTC is generated if response is missing from all units on the VR-bus.
Cause of the problem may be:
- open circuit between control module pin 14 and crimp J159
- shorting to ground on bus
- internal shorting in a relay or valve
Check the voltage between the VR-bus+ and ground using a multimeter. The voltage should be approximately 4.3 V