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Home >> Toyota >> 2001 >> Sienna CE >> Repair and Diagnosis >> External Pages >> Different car >> Section 97 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0128: Thermostat Fault >> Diagnosis & Repair

Diagnosis & Repair

WARNING: This page is about a different car, the 2003 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Drain cooling system. Remove and test thermostat. Replace thermostat as necessary. If thermostat is okay, install thermostat and refill cooling system. Go to next step.
  2. If any other DTCs are displayed, diagnose and repair those DTCs first and retest system. If only DTC P0128 is displayed, replace ECM and retest system.