Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Coolant temp sensor

my 2008 fusion with 2.3 I-4 has an obd-ii code p0128 which is “low coolant temperature”. the dash temp gauge reads the same as always, about in the middle, the coolant level is fine. does that indicate the sensor? where is the coolant temp sensor on this car?

There could be at least three coolant temp sensors on the engine. One for the gauge on the dash, one for the radiator cooling fans, and one for the engine computer. The one for the engine computer is the one with the problem.

This sensor is located at the rear of the engine.


Is this covered under your warranty? Let the dealer sort it out.

the car already exceeds the bumper-to-bumper warranty coverage, and it’s unlikely this problem will qualify under the powertrain warranty

The gauge may be programmed to not show any variance until it’s way out of range. Most worked that way. It limited the customer complaints about running too hot.

So far I’ve heard nothing that indicates that the temp has been verified as normal (taking the potential for a numb temp indicator).

I would change the thermostat. Cheap …basic…

btw- I only saw one coolant temp sender on RockAuto for this car. I checked all the sub categories and could find no rad temp sender …but that doesn’t mean that it doesn’t exist. Ford did complicate things with their fail safe cooling system. In some models it had up to 7 inputs to run the fans. That’s not to say 7 sensors, but rather 7 conditions with only one being coolant temp determined when they would turn on and to what speed.