Code P0128

Tiny
559ASKAMECH
  • MEMBER
  • 2012 FORD FUSION
  • 3.0L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 105,000 MILES
Hello, my engine light came on with the P0128 code, which is to possibly replace the coolant temperature thermostat sensor or the actual thermostat. I replaced my thermostat recently so I am assuming that my sensor is bad, but I am a bit confused on which sensor is for my car since is a 2012 Ford Fusion SEL 3.0 and the auto parts tech is asking if is a head cylinder sensor or a screw in sensor. Can you possibly give some feedback on what sensor could this be?

Thanks,

Guillermo.
Saturday, January 9th, 2021 AT 12:46 PM

8 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good afternoon,

It could be the sensor but I doubt it. It is about the temperature of the coolant is too low.

https://www.2carpros.com/articles/how-a-coolant-temperature-sensor-works

What temperature thermostat did you replace the original? You need a 195-degree thermostat.

https://www.2carpros.com/articles/replace-thermostat

I would try a new thermostat. That is the most common failure.

Roy

Removal and Installation

1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to Vehicle Jacking and Lifting. See: Vehicle Lifting > Procedures > Jacking and Lifting.

2. Drain the cooling system. For additional information, refer to Cooling System Draining, Filling and Bleeding See: Cooling System > Procedures > Cooling System Draining, Filling and Bleeding.

3. Disconnect the positive battery cable. For additional information, refer to Section 414-01 See: Battery > Removal and Replacement > Battery.

4. Disconnect the lower radiator hose from the thermostat housing.

5. Remove the 2 bolts, thermostat housing cover, O-ring seal and thermostat.
To install, tighten to 10 Nm (89 lb-in).

6. NOTICE: Use Motorcraft(R) Specialty Green Engine Coolant or Motorcraft(R) Specialty Orange Engine Coolant. Use the same type of coolant that was originally used to fill the cooling system. Do not mix coolant types. Mixing coolant types degrades the coolant corrosion protection and may damage the engine or cooling system.
NOTICE: Motorcraft(R) Specialty Green Engine Coolant is very sensitive to light. Do NOT allow this product to be exposed to ANY LIGHT for more than a day or two. Extended light exposure causes this product to degrade.

To install, reverse the removal procedure.

Clean and inspect the O-ring seal. Install a new seal if necessary.

Lubricate the thermostat O-ring seal with clean engine coolant.

7. Fill and bleed the cooling system. For additional information, refer to Cooling System Draining, Filling and Bleeding See: Cooling System > Procedures > Cooling System Draining, Filling and Bleeding.
Was this
answer
helpful?
Yes
No
Sunday, January 10th, 2021 AT 9:15 AM
Tiny
DONALD81
  • MEMBER
  • 3 POSTS
  • 2007 FORD FUSION
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 90,000 MILES
Car turns over but takes it very many times to finally start. Read the codes for the check engine light being on and it reads, check engine code reads coolant thermostat coolant temperature beloiw thermostat temp
Was this
answer
helpful?
Yes
No
Friday, February 19th, 2021 AT 6:16 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Check and test the engine coolant temperature sensor-
Was this
answer
helpful?
Yes
No
Friday, February 19th, 2021 AT 6:16 PM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
Best is you can supply us with the codes so we can help in pin pointing the troubled area
Coolant below thermostat temp is an indication of a bad thermostat (open)and need to be replaced
Was this
answer
helpful?
Yes
No
Friday, February 19th, 2021 AT 6:16 PM (Merged)
Tiny
DONALD81
  • MEMBER
  • 3 POSTS
The code is P0128 MOD $00 Coolant Temp Below Thermostat Regulating Temp
Was this
answer
helpful?
Yes
No
Friday, February 19th, 2021 AT 6:16 PM (Merged)
Tiny
DONALD81
  • MEMBER
  • 3 POSTS
P0128 MOD $00 Coolant Temp Below Thermostat Regulating Temp
Was this
answer
helpful?
Yes
No
Friday, February 19th, 2021 AT 6:16 PM (Merged)
Tiny
D2OFAKIND
  • MEMBER
  • 7 POSTS
I wouldnt be to concerned with the Thermostat, you have a much bigger problem, it is that oval on the front of the car that says ford! Sorry man I couldnt pass it up.
Was this
answer
helpful?
Yes
No
Friday, February 19th, 2021 AT 6:16 PM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature) Detailed Description
Indicates that the thermostat monitor has not achieved the required engine operating temperature within a specified amount of time after starting the engine.

Possible causes :-
Insufficient warm up time
Low engine coolant level
Leaking or stuck open thermostat
Inoperative engine coolant temperature (ECT) sensor
Inoperative cylinder head temperature (CHT) sensor
WE FIND IT VERY COMMON FOR THE THERMOSTAT TO BE AT FAULT
CHECK COOLANT 1ST
Was this
answer
helpful?
Yes
No
Friday, February 19th, 2021 AT 6:16 PM (Merged)

Please login or register to post a reply.

Sponsored links