Toyota P0128 Engine Coolant Temperature Below Thermostat Regulating Temperature

Description

OBD-II Trouble Code Description for P0128 Toyota

Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

What does this mean?

OBD2 Code P0128 Toyota definition:
This means that the engine’s PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 Toyota code is to indicate a faulty thermostat. Similar codes: P0125 Toyota In determining the engine did not reach a “normal” temperature, it takes into account the length of time the vehicle has been running, the intake air temperature (IAT) sensor reading, the engine coolant temperature (ECT) sensor reading, and the speed of the vehicle.

Symptoms

Possible sumptoms of OBD code P0128 Toyota
You will likely not notice any drivability problems other than the MIL illumination.

Causes

Possible causes of OBD code P0128 Toyota
A code P0128 Toyota may mean that one or more of the following has happened: Low engine coolant level Leaking or stuck open thermostat Faulty cooling fan (running too much) Faulty coolant temperature (ECT) sensor Faulty intake air temperature (IAT) sensor

Possible Solutions

Past experience indicates that the most likely solution is to replace the thermostat. However here are some suggestions on troubleshooting and repairing a P0128 Toyota OBD-II code: Verify coolant strength & level Verify proper cooling fan operation (check if it’s running more than it should). Replace if necessary. Verify proper engine coolant temperature (ECT) sensor operation, replace if necessary. Verify proper intake air temperature (IAT) sensor operation, replace if necessary. If the above items check out good, replace the thermostat If Nissan vehicle, check for Technical Service Bulletins (TSBs), as the ECM may need to be reprogrammed to correct the P0128 Toyota code

Related Codes

P0115 Toyota P0116 Toyota P0117 Toyota P0118 Toyota P0119 Toyota P0125 Toyota


The OBD2 Code Information Be Applicable For Toyota:

2013 Toyota Auris,2012 Toyota Yaris,2012 Toyota Verso-S,2012 Toyota Tacoma,2012 Toyota Prius V,2012 Toyota Prius C,2012 Toyota Prius,2012 Toyota Hilux,2012 Toyota Camry,2012 Toyota Avensis,2012 Toyota Aurion,2012 Toyota 86 GTS,2011 Toyota Tacoma,2011 Toyota Sienna,2011 Toyota Sequoia,2011 Toyota RAV4,2011 Toyota Matrix,2011 Toyota Highlander,2011 Toyota Corolla,2011 Toyota Avalon,2011 Toyota Auris HSD,2010 Toyota iQ3,2010 Toyota Yaris,2010 Toyota Verso,2010 Toyota Tundra,2010 Toyota Prius,2010 Toyota Land Cruiser,2010 Toyota Corolla,2010 Toyota Camry,2010 Toyota Auris,2010 Toyota 4Runner,2009 Toyota iQ,2009 Toyota Yaris,2009 Toyota Venza,2009 Toyota RAV4,2009 Toyota Matrix,2009 Toyota Hilux,2009 Toyota Aygo,2009 Toyota Avensis,2009 Toyota Aurion,2009 Toyota 4Runner,2008 Toyota Sequoia,2007 Toyota Tundra,2007 Toyota Avensis,2006 Toyota RAV4,2006 Toyota Aurion,2005 Toyota Corolla Sedan,2004 Toyota Prius,2004 Toyota Corolla,2003 Toyota RAV4,2003 Toyota Land Cruiser,2003 Toyota Celica

 

Note:

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