DTC B1800/51: Short in Driver Side Squib Circuit; DTC B1801/51: Open in Driver Side Squib Circuit; DTC B1802/51: Short to GND in Driver Side Squib Circuit; DTC B1803/51: Short to B+ in Driver Side Squib Circuit [08/2013 - ]: Wiring Diagram
WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.