2014–2018 Toyota Highlander: Stalling, misfires or warning lights (ECM connector corrosion)
Likely causes, ranked
- Water corrosion in the A43 ECM connector (connector, harness or ECM replaced)Shop
- Leaking aftermarket windshield deicer harness letting water inShop
Real-owner fix counts will appear here as reports come in.
DIY or shop: See DIY or shop section
Parts to check
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- Water corrosion in the A43 ECM connector on Amazon
- Leaking aftermarket windshield deicer harness letting water in on Amazon
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Symptom: Stalling, misfires, low fuel pressure, or a cluster of codes such as P0171 and P0300.
Likely causes
- Corroded ECM connector. Toyota's bulletin traces it to water entering the ECM connector.
- Windshield deicer harness. Poorly sealed windshield deicer wiring is a common entry point.
DIY or shop?
Dealer or shop.
Useful steps
- Ask for T-SB-0072-19.
- Have the connector inspected.
Vehicle focus: 2014–2018 Toyota Highlander.
Safety / mechanic note
Stalling is dangerous. Verify with a mechanic.
Related trouble codes
Recalls & service bulletins
Technical service bulletins
- T-SB-0072-19 Toyota bulletin for drivability problems and DTCs on 2014–2018 Highlanders caused by water corrosion in the A43 ECM connector. Details
NHTSA complaints: 158 keyword-matched complaints (of 996 unique complaints filed under NHTSA model names HIGHLANDER, HIGHLANDER HV, HIGHLANDER HYBRID, 2014–2018; NHTSA complaints API by model year, queried 2026-10-15).
Always check your VIN for open recalls at nhtsa.gov/recalls.
Sources
What actually fixed it?
Had this problem? Tell other owners what the real fix was. Reports are counted above; we never show made-up numbers.