Luggage compartment lighting: Diagnosis
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 output has an overload protection that shuts the output off if the load is too high. This activates DTC B1235.
DTCs are not generated if the voltage is below 11V or during diagnostic communication.