DTC P1312: Combustion Detection Cyl. 1+2. Open Circuit/Short to B+.: Notes
WARNING: This page is about a different car, the 2003 Saab 9-3 and 2002 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Circuit Diagram - Combustion Detection Cyl. 1+2 - Open Circuit/Short To B+