Toyota Highlander 2014–2017 — technical service bulletin
Bulletin T-TT-0462-17 · NHTSA communication 10146520 · issued Nov 14, 2017
Technical service bulletin
communication type
Fuel System, Other
component
2014–2017
model years
4
vehicle entries
Official summary
T-TT: Vehicles may experience various drivability concerns. Upon diagnosis, technicians commonly find no or low fuel pressure as well as a variety of DTCs (Commonly P1603, P1604, P1605, P0171, P0300, P0302, P0304, U0100). Technicians find that the cause this condition is corrosion and water in the A43 ECM connector (Fig 1). In several cases, it was found that the source of water was from aftermarket windshields with poorly sealed or damaged deicer harnesses (Fig 2). Water enters the deicer harness and is wicked through the engine room main harness, eventually collecting in the ECM connector.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.