how to fix the P0128 code in my Toyota Corolla E210 (2019-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the engine is cool before beginning work.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace the Thermostat

• Tools Required: Socket set, torque wrench, gasket scraper, coolant catch pan.
• Sub-steps:
  1. Drain the engine coolant into a catch pan by loosening the drain plug on the radiator.
  2. Remove the engine cover if applicable.
  3. Locate the thermostat housing, typically found near the engine block.
  4. Disconnect any hoses connected to the thermostat housing.
  5. Remove the bolts securing the thermostat housing using a socket set.
  6. Carefully lift the housing to access the thermostat; note its orientation.
  7. Remove the old thermostat and inspect the housing for any debris or damage.
  8. Clean the mating surface with a gasket scraper to ensure a proper seal.
  9. Install the new thermostat in the same orientation as the old one.
  10. Reattach the thermostat housing and torque the bolts to the manufacturer's specifications (usually around 15-20 ft-lbs).
  11. Reconnect the hoses.

3. Refill Coolant

• Sub-steps:
  1. Refill the cooling system with the appropriate type of coolant (usually a 50/50 mix of coolant and distilled water).
  2. Start the engine and let it idle until it reaches operating temperature, monitoring for leaks.
  3. Check the coolant level after the engine has cooled and top off if necessary.

4. Reconnect Battery

• Reconnect the negative battery terminal.