Coolant Temperature Sensor ECTS
Coolant sensors are a very important piece of the puzzle that makes up the engine
management system in your vehicle. Your vehicles
PCM (Computer) uses
the information gathered from the coolant temperature sensor to know how rich or
lean the engine needs to be according to engine temperature. The coolant temp sensor
or “ECTS” (Electronic Coolant Temperature Sensor) is what provides this information
as well as where the temperature gauge should read on most vehicles, it is not to
be confused with a “Coolant Sender” which is strictly for a gauge and not the PCM.
A Coolant Temp Sensor will usually have multiple wires (Usually 2) whereas a Coolant
Temp Sender usually only has 1 wire. Consult an
automotive service manual
for the exact location of the coolant sensor on your vehicle.
When you go to start your vehicle, one of the first things the computer looks
at is the
engine temperature; this
dictates what parameters it will use for initial start up. When your vehicle is
cold it runs in “Open Loop” which is a set of programmed parameters, once warmed
up the coolant sensors tells the computer to go to “Closed Loop”, this is when the
sensors really take over and the mixture is adjusted for emissions. A coolant sensors
job is varying resistance to determine engine temperature, this is why sometimes
the sensor can be out of correct operating range and not set a
check engine light, even though the vehicle isn’t running properly. When an
coolant sensors fails or goes out of range it can affect the idle quality,
fuel mileage, and generally
the overall performance of the vehicle.
When diagnosing a check engine light due to a coolant sensor fault a few things
must be taken into consideration: Is the cooling system full? Coolant sensors can’t
read air, they need to be immersed in fluid to work properly. Has the vehicle been
overheated? Overheating
the vehicle will put the sensor at the far end of its operating range, possibly
too far, this will set a check engine light for the sensor when the engine overheating
is actually the cause. Does the engine temperature gauge show the
engine isn’t
warming up to normal range?
This too can set a coolant sensors code in the computer,
when the sensor doesn’t see the engine warming up in a reasonable amount of time
it can set an coolant sensors related
code, when
it may just be a
thermostat
stuck open or broken. The sensor will have a particular resistance across the terminals,
you will need to refer to an automotive service manual for your vehicle for the
exact specification and location of the sensor. If the sensor is found to be faulty,
always use a high quality OEM (Original Equipment Manufacturer) replacement part
or the equivalent.
If further assistance is needed, our certified car repair technicians
are ready to
answer your car questions.
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