how to fix P0128 code in my Volvo XC60 536 (2017-Present)

Learn how to diagnose and fix P0128 code in Volvo XC60. Step-by-step guide with diagnostic procedures and repair instructions for cooling system issues.

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool completely before proceeding.

2. Replace Thermostat

1. Drain Coolant:

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

2. Remove Thermostat Housing:

   • Locate the thermostat housing on the engine block. Remove the bolts securing the thermostat housing using a socket set.
   • Gently pry the housing off, taking care not to damage the gasket surface.

3. Replace Thermostat:

   • Remove the old thermostat from the housing.
   • Install the new thermostat in the correct orientation (the jiggle valve should be at the top).
   • Ensure the mating surfaces are clean and free of old gasket material.

4. Reinstall Thermostat Housing:

   • Apply a thin layer of gasket maker or install a new gasket if applicable.
   • Reattach the thermostat housing and torque the bolts to the manufacturer's specifications (typically 15-20 Nm).

5. Refill Coolant:

   • Close the radiator drain valve and refill the cooling system with the appropriate coolant type.
   • Start the engine and allow it to reach operating temperature while monitoring coolant levels.

3. Replace Coolant Temperature Sensor (if needed)

1. Locate Sensor:

   • Find the coolant temperature sensor, usually located near the thermostat housing.

2. Disconnect Wiring:

   • Carefully disconnect the wiring harness from the sensor.

3. Remove Sensor:

   • Using a socket or wrench, unscrew the sensor from the engine block.

4. Install New Sensor:

   • Apply thread sealant to the new sensor (if required) and install it in the engine block.
   • Reconnect the wiring harness firmly.