how to fix the P0128 code in my Tesla Outback 4th Generation (2010-2014)

Learn how to diagnose and fix P0128 cooling system issue in Subaru Outback (2010-2014). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical issues.

2. Inspect and Replace the Thermostat

1. Drain Coolant:

   • Place a drain pan under the radiator.
   • Open the radiator drain valve and allow coolant to drain completely.

2. Remove the Thermostat:

   • Locate the thermostat housing (usually at the engine end of the upper radiator hose).
   • Disconnect the upper radiator hose from the thermostat housing.
   • Remove the bolts securing the thermostat housing using a socket set.
   • Carefully lift the housing off to access the thermostat.

3. Inspect the Thermostat:

   • Check the thermostat for any signs of wear or damage.
   • Test the thermostat in hot water to ensure it opens at the correct temperature.

4. Install New Thermostat:

   • Clean any old gasket material from the mating surfaces.
   • Place the new thermostat into the housing and align it properly.
   • Reattach the thermostat housing and torque the bolts to manufacturer specifications (typically around 15-20 ft-lbs).

5. Reconnect Upper Radiator Hose:

   • Ensure the hose is securely attached and clamp it back in place.

3. Refill Coolant

• Refill the cooling system with the appropriate coolant mixture.
• Start the engine and allow it to reach operating temperature, checking for leaks.