TSB: Some 2013 ? 2015 model year GS 450h vehicles may exhibit a condition where the brake, ABS, and/or TRAC warning lights are on and/or a Check VSC message displays. One or more of the following specific Diagnostic Trouble Codes (DTCs) C1391, C1252, C1256, or C1253 will be stored in the vehicle memory to be used as verification. This condition may be caused by a small internal brake fluid leak inside the brake actuator. Follow the Repair Procedure in this bulletin to address this condition.
