Thermostat Re-Installation Procedure – Repeat Repair (DTC P0128) – 2010-2013 Kia Forte

PS267

 

SUBJECT:

THERMOSTAT RE-INSTALLATION PROCEDURE – REPEAT REPAIR (DTC P0128)

 

When diagnosing a Forte returning with a repeat DTC P0128 after replacement of the thermostat, remove the thermostat housing to verify if the thermostat was installed incorrectly during the previous repair. Incorrect installation may be difficult to determine due to the sideways orientation of the thermostat housing, however, pay close attention when the housing is removed for coolant flowing out and displacing the thermostat as soon as the housing is separated. In some cases if the housing is closely inspected, witness marks on the housing or gasket outside of the thermostat outer edge may be visible; if so, the thermostat was installed incorrectly (Fig. 1).

 

 

*NOTICE

Removing the upper coolant hose from the housing will relieve tension and make the thermostat installation easier.

To prevent any further repeat repairs, follow the procedure outlined on KGIS and remove all necessary components to gain proper access, including the air box assembly. Correctly position the thermostat in the housing by aligning the tab on the thermostat housing (Fig. 3) with the tab on the thermostat body (Fig. 4). Try rotating the thermostat to validate if it is properly indexed and seated. No movement should be possible, if properly installed. Make sure the thermostat does not move during installation of the housing as this could cause repeat repairs.