Conditions for Setting the DTC
WARNING: This page is about a different car, the 2011 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
C0450 0B
The actuator current exceeds 4.5 amps.
C0450 02
The actuator current is detected as less than 50 percent of its expected current while the actuator is commanded OFF.
C0450 04
The current through the actuator is not within 0.5 amp of its commanded value.