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 the relay in question.

The cause of the problem could be power supply, grounding or that bus connection is missing.

Try replacing the fifth bow latch relay with, for example, the relay for the right front window.
Activate the relay with the button for the right front window on the center console.
The latch motor should lock or unlock the fifth bow.
If the fifth bow locks or unlocks, the problem is likely in the latch relay