Conditions for Setting the DTC
WARNING: This page is about a different car, the 2005 Suzuki Swift +, 2005 Pontiac Wave, and 2005 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
DTC C1206 can be set anytime the key is ON and the EBCM has detected an open, short to ground, or a short to battery on the left rear wheel speed circuit.