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Any Toyota Techs Out There?

bkglock

Field Marshal
Full Member
Minuteman
Nov 9, 2002
231
305
USA
I have a 2005 Toyota Matrix that I need a little help with.
The radiator fan cycles on and off a lot. Even when the car is cold in the morning and you start it, the fan will come on for about 30 seconds then turn off. After a minute or two the fan will come on again and run for about 30 seconds. This continues the entire time the engine is running. Otherwise, the car runs and performs just fine.
Any ideas what might be wrong? Bad sensor of some sort maybe. Any help would be appreciated, thank you.
 
Fans are most commonly controlled by coolant temp sensor, oil temp sensor, AC systems have a high pressue switch to kick the fan on. And even some power steering systems have temp sensors that will kick on your engine fan. Fan wiring, weak fan relay.
So many possible issues. Although yours sounds very intermittent. Like spread pins someplace.

If you're keen on doing some in depth diagnostics yourself.
You'll have to obtain wiring diagrams and figure out first how the fan is controlled. And what exactly controls it. Trace the diagrams.
Obtain all the reistance values for each senor.. get a multimeter and test them
Check all your senor connectors for spread pins and broken Wires.
test the fan relays, fuses and Possible circuit breaker. Have a look at all your connectors and if nothing pops out at you.

Probably best to drop it off at the dealer.
They can most likely hook up with their proprietary diagnostic program and instantly see which sensor or circuits are possibly throwing a fault codes.. that is if the whole system is computer controlled.
Good luck.
 
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Had a Dodge where the fan clutch was broken. The fan turned on, but didn't pull much air. Something to look at.
 
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I have a 2005 Toyota Matrix that I need a little help with.
The radiator fan cycles on and off a lot. Even when the car is cold in the morning and you start it, the fan will come on for about 30 seconds then turn off. After a minute or two the fan will come on again and run for about 30 seconds. This continues the entire time the engine is running. Otherwise, the car runs and performs just fine.
Any ideas what might be wrong? Bad sensor of some sort maybe. Any help would be appreciated, thank you.
Not Toyota specifically but I’ve been a mechanic for a while.

Does the fan do this if the climate control is completely off? The fan will be turned on if the climate control unit is turning the a/c compressor on. This could possibly be normal operation

Is the coolant temp gauge doing anything weird when the fan is being weird? That could be an easy fix of replacing the coolant temp sensor

If it’s been a while since you’ve had any cooling system work done, replacing the thermostat, flushing/cleaning the cooling system with a specific cleaning additive, and cleaning all of the dirt from between the radiator cooling fins are some things you could try that don’t cost much and can’t hurt anything
 
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If the climate control is off, it does not do it. Temp. gauge acting normal. Thanks for the meaningful replies. Beginning to think that this is normal operation.
 
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If the climate control is off, it does not do it. Temp. gauge acting normal. Thanks for the meaningful replies. Beginning to think that this is normal operation.
I’ll add some more maintenance items that nobody thinks about. Have your a/c system emptied/refilled and replace the receiver drier. It sounds like it’s working normally but the desiccant inside could be getting inefficient.
 
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Ask Scotty Kilmer. He loves the Toyota Matrix.
That asshat doesn't even know how to spell car, let alone how one works.

And yes, with A/C or def on it's normal behavior.....but low on freon could cause excessive fan run times as the compressor will cycle on and off faster.
Summers coming up and probably not a bad idea to check the a/c pressures to be sure it's full.
 
Sounds like you are probably not having an issue, but a couple comments anyway

This guy has the best Toyota vids on youtube


In old Toyotas it is not uncommon for the ECT to just wear out.


takes 10 minutes to replace and is like $10-$15
looks like this

1715018594460.png


I replace them when I do a thermostat like standard maintenance.

Normally when the ECT fails it is stuck in "the engine is cold position" which would not cause fans to turn on. The usual symptom is slow to start on hot restarts because the ecu is adding fuel like the engine is cold.

Food for thought to just replace the ECT as general maint, 100k to 150k
 
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