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Canada - Cooling System - MIL ON/DTC P0128/P0116

Bulletin
TSB2781

Issue Date
March 17, 2010

Title
MIL "ON" DTC P0128 OR P0116

Component
ENGINE MECHANICAL

Models
'08-'09 GS350; GS450h; IS250; IS350

INTRODUCTION:

Some 2008 - 2009 model year vehicles equipped with a 2GR-FSE or 4GR-FSE engine may exhibit a MIL "ON" condition with one or more of the following Diagnostic Trouble Codes (DTCs):
- P0128 - Coolant Thermostat (Coolant Thermostat Below Thermostat Regulating Temperature)
- P0116 - Engine Coolant Temperature Range/Performance Problem

Use the following repair procedure to diagnose and repair customer complaint vehicles.






APPLICABILITY:






WARRANTY INFORMATION:

PRODUCTION CHANGE INFORMATION:






This TSB applies to vehicles produced BEFORE the Production Change Effective VIN shown.






PARTS INFORMATION:






REQUIRED TOOLS & EQUIPMENT:

REPAIR PROCEDURE:

1. Using ETAS Techstream, check for any stored DTCs.
2. If DTCs P0128 and/or P0116 are present, remove and inspect the thermostat housing and thermostat.










Is the thermostat assembly securely seated in the thermostat housing? See Figures 1 and 2 for reference.
- YES - This TSB does NOT apply. Refer to the Repair Manual and follow diagnostics for the DTC.
- NO - Go to step 3.

3. Replace the thermostat and thermostat housing.

Refer to the Repair Manual within E-TAS / TIS library:
- Division: Lexus
- Model: GS350/ GS450h/IS350
- Year: 2008/ 2009
- Service Category: Engine/Hybrid System
- Section: Cooling
- Keyword: 2GR-FSE Cooling: Thermostat: Removal / Installation

- Division: Lexus
- Model: IS250
- Year: 2008/ 2009
- Service Category: Engine/Hybrid System
- Section: Cooling
- Keyword: 4GR-FSE Cooling: Thermostat: Removal / Installation

4. After the repair is complete, clear any stored DTCs and test drive the vehicle to confirm the repair.

NOTE:
Issue of this Technical Service Bulletin is to ensure that proper repair information is available. IT DOES NOT CONSTITUTE AN AUTHORIZATION FOR REPAIR. Normal provisions of the formal warranty policy, as applicable, will apply.