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2026 PORSCHE TAYCAN
4S Dual Motor AWD•AWD•AUTOMATIC•ev
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Repairs0Labor327Torque63Fluid5DTC742Battery1Maintenance0Recalls0
P0128low severityPowertrain

Coolant Thermostat Below Regulating Temperature

on 2026 Porsche Taycan 4S Dual Motor AWD · AWD

What this code means

The engine coolant has not reached the expected temperature within a specified time after startup.

Symptoms

  • Check Engine Light
  • Poor fuel economy
  • Heater not getting hot
  • Engine running cool

Common causes

  • Stuck-open thermostat
  • Missing thermostat
  • Faulty ECT sensor
  • Cooling fan stuck on

Diagnostic steps

  1. Monitor ECT warmup curve
  2. Check thermostat
  3. Verify fan operation
  4. Test ECT sensor

Repair notes

Replace thermostat.

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🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Mechanic · 20+ years. Spot an error? Use the Help link above — a human reads every report.
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