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.

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Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.

About the Author

Mike Mavrigian | Editor

Mike received a BA degree from Youngstown State University in English Literature with a minor in Journalism in 1975.