Daniel Foster

I need to replace the ECT sensor on my 2.5 L v6 2002 tracker but know little about working on cars. A mechanic told me that depending on the location, the replacement could take 1-4 hours. For a $40 part I don't want to pay for 4 hours of service. Does anyone know how long this job takes or how easy it would be to do myself?
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Irish_alley

look for it. you might loose some coolant but its not a hard job. never done one on the tracker but it doesnt look too hard

L84sky

The service manual implies this is a ten minute job. Be prepared to spend an hour or more.




Halfway down the transmission dipstick tube you will see the ECT sensor screwed into the back of the engine.




Your first challenge is to remove the electrical connector. You must press the release tab and simultaneously pull
the connector to the rear of the car. This is not easy and may require several attempts. The next step is to turn the
22 mm nut counter-clockwise until the sensor comes out of the engine. You may find it helpful to first remove the
12 mm bolt holding the dipstick tube to the engine. This will give you just enough clearance to get a wrench on
the sensor in a way that you will be able to turn the wrench. If you did not drain the radiator, fluid will spew out.
It's safer if the engine is cold when this happens. This is a totally doable job for a beginner. It's just going to take
longer and be more frustrating than you expect.

L84sky

Unlike newer cars with sensor data multiplexed onto class 2 serial busses or Controller Area Networks (CAN), the Tracker uses good old fashioned dedicated wire
analog gauges. It's more expensive to run a separate wire for every circuit but it makes it easier for the DIYer to troubleshoot. In the case of the coolant temperature
sensor the Tracker uses a dual-element sending unit. One output is sent directly to the instrument panel and the other is sent to the computer.




Any scanner that can read real-time data will show the value being sent to the PCM.




The instrument panel gauge should indicate a similar value. The coolant temperature can be
verified with an infrared thermometer at the thermostat housing.

L84sky

The Tracker ECT schematic (above) has a small error.


When Chevy redrew the Suzuki schematic to conform to GM specifications they
inadvertently tied both ECT elements to sensor ground. This is incorrect. Only the
element going to to the PCM uses the sensor ground. The element going to the
instrument cluster uses a chassis ground (where it threads into the engine block).




Chassis ground is pin 4 on the Data Link Connector (DLC) while the sensor
ground (aka signal ground) is found on pin 5.




Except for G102 & G103 all the grounds on a 2001 V6 are chassis grounds.




The three round lugs that comprise the sensor (or signal) grounds terminate at a signal point on
the rear of the intake manifold (driver's side).