Corrosion Causing Toyota Drivability Issues
Some 2014-2018 Toyota Highlander and Highlander Hybrid vehicles may exhibit one or more of the following conditions:
- Various drivability concerns
- Low or no fuel pressure
- DTCs including but not limited to P1603, P1604, P1605, P0171, P0300, P0302, P0304 and U0100
- Some 2014-2018 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 on Hybrid models. The corrosion in these connectors is due to poorly sealed or damaged aftermarket windshield deicer harnesses.