how to fix P0128 code in Ford F-150 Fourteenth Generation (2021-present)

Learn how to diagnose and fix P0128 code in Ford F-150. Step-by-step guide with diagnostic procedures and repair instructions for cooling system issues.

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, screwdriver set, multimeter, coolant.
• Safety Warnings: Allow the engine to cool completely before working on the cooling system to prevent burns.

2. Replace Thermostat

1. Drain Coolant:

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

2. Remove Thermostat Housing:

   • Disconnect the negative battery terminal.
   • Remove the bolts securing the thermostat housing using a socket set.
   • Carefully lift off the housing and remove the old thermostat.

3. Install New Thermostat:

   • Clean the mating surfaces on the engine and thermostat housing to remove old gasket material.
   • Place the new thermostat in the housing, ensuring it is oriented correctly (check for any markings).
   • Apply a new gasket or gasket maker as required, and reattach the thermostat housing with the bolts. Torque them to the manufacturer’s specifications (typically around 15-20 ft-lbs).

3. Refill Coolant

• Refill the cooling system with the appropriate type of coolant as specified in the owner’s manual.
• Start the engine and allow it to reach operating temperature, checking for leaks.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0128 code.