Lexus coolant codes

Some 2008-2009 Lexus vehicles equipped with the 2GR-FE or 4GR-FE engine may exhibit a MIL “ON” condition with one or both of the following codes:

P0128 (Coolant Thermostat belowThermostat Regulating Temperature)

P0116 (Engine Coolant Temperature Range/Performance Problem)

This TSB applies to vehicles produced before the Production Change Effective VINs shown below:

MODEL          PLANT           DRIVETRAIN          PROD. CHANGE EFF. VIN

GS 350          Tahara           2WD                         JTHBE96S*90045581

GS 350           Tahara          4WD                         JTHCE96S*90023172

GS450h          Tahara          2WD                         JTHBC96S*95019778

GS450h          Tahara          4WD                         JTHCK262*95033047

IS 250             Tahara          2WD                         JTHBK262*05099794

IS 250             Tahara          4WD                         JTHCK262*95033047

IS 250             TMK               4WD                         JTHCK262*92032298

IS 250             TMK               2WD                         JTHBK262*92094026

IS 350             Tahara          2WD                         JTHBE262*95023043

IS 350             TMK               2WD                         JTHBE262*92017385

REPAIR PROCEDURE

1. Using Techstream, check for any stored DTCs.
2. If DTCs P0128 and/or P0116 are present, remove and inspect the thermostat housing and thermostat.
3. If the thermostat is not securely seated in the thermostat housing, replace the thermostat and the thermostat housing.