TSB: Some 2014 ? 2018 model year Highlander and Highlander Hybrid vehicles may exhibit one or more of the following conditions.
? Various drivability concerns ? Low or no fuel pressure ? Diagnostic Trouble Codes (DTCs) (Including but not limited to P1603, P1604, P1605, P0171, P0300, P0302, P0304, U0100) ? Some 2014 ? 2018 model year Highlander Hybrid vehicles may exhibit DTC P134A. These conditions may be caused by corrosion/water in the A43 ECM connector (Highlander) or the A9 inverter water pump connector (Highlander HV). The corrosion in the A43 and A9 connectors is due to poorly sealed or damaged aftermarket windshield deicer harnesses. Follow the Repair Procedure in this bulletin to address these conditions.
