01 Camry engine cooling fans "always on"

[camry_jc]

Hi, searched around in the forums but failed to find an apropos topic. Engine cooling fans on my 01 Camry, 4 cyl, 5 speed manual, are stuck "on".

what part do I need to buy and replace? All the reading i did do on the subject in here suggested a relay is not right/busted, would like confirmation on applicability for the '01 Camry and also which part to get (URL, part #, etc) and where it is located in the engine compartment.

Thanks

[hill8570]

I'd generally suspect the temp sensor down on the bottom passenger side of the radiator, but there are other possibilities. Do you have a multimeter? Easy to check that beast if so, and I'd rather do some simple diagnostics rather than just shotgun in parts. Let me know...

[slavie]

I would suggest you first check all the fan connectors to make sure all are plugged in nice and tight. If one of them (forgot which one exactly) is unplugged, fans will stay on all the time.

[houra]

check the temperature sensor connector at the bottom of radiator

[houra]

1. CHECK COOLING FAN OPERATION WITH LOW TEMPERATURE (Below 83°C (181°F))
(a) Turn the ignition switch ON.
(b) Check that the cooling fan stops.
If not, check the cooling fan relay and ECT switch, and check for a separated connector or severed wire between the cooling fan relay and ECT switch.
(c) Disconnect the ECT switch connector.
(d) Check that the cooling fan rotates.
If not, check the fan main relay, cooling fan relay, cooling fan,
fuses, and check for short circuit between the cooling fan relay
and ECT switch.
(e) Reconnect the ECT switch connector.

2. CHECK COOLING FAN OPERATION WITH HIGH TEMPERATURE (Above 93°C (199°F))
(a) Start the engine, and raise coolant temperature to above 93°C (199°F).
(b) Check that the cooling fan rotates.
If not, replace the ECT switch.

[camry_jc]

Originally Posted by hill8570

I'd generally suspect the temp sensor down on the bottom passenger side of the radiator, but there are other possibilities. Do you have a multimeter? Easy to check that beast if so, and I'd rather do some simple diagnostics rather than just shotgun in parts. Let me know...

Yes, I have a digital multimeter.
Specific instructions appreciated.

[camry_jc]

Originally Posted by houra

1. CHECK COOLING FAN OPERATION WITH LOW TEMPERATURE (Below 83°C (181°F))
(a) Turn the ignition switch ON.
(b) Check that the cooling fan stops.
If not, check the cooling fan relay and ECT switch, and check for a separated connector or severed wire between the cooling fan relay and ECT switch.
(c) Disconnect the ECT switch connector.
(d) Check that the cooling fan rotates.
If not, check the fan main relay, cooling fan relay, cooling fan,
fuses, and check for short circuit between the cooling fan relay
and ECT switch.
(e) Reconnect the ECT switch connector.

2. CHECK COOLING FAN OPERATION WITH HIGH TEMPERATURE (Above 93°C (199°F))
(a) Start the engine, and raise coolant temperature to above 93°C (199°F).
(b) Check that the cooling fan rotates.
If not, replace the ECT switch.

OK, I can give this a go. A few questions - where is the cooling fan relay? Where is the ECT switch (what does ECT stand for)? And, when you say "check" it, am I measuring resistance, etc. ? what is the procedure?

Thanks a bunch! going to have at it on Sat.

[Mister_Perkins]

Originally Posted by camry_jc

OK, I can give this a go. A few questions - where is the cooling fan relay? Where is the ECT switch (what does ECT stand for)? And, when you say "check" it, am I measuring resistance, etc. ? what is the procedure?

Thanks a bunch! going to have at it on Sat.

The Cooling Fan Relays are located on the drivers side of the engine bay.

The ECT ( Engine Coolant Temperature ) Sensor is located at the bottom of the radiator. It detects how hot the coolant is, and once the coolant reaches a certain temperature it in-turn Kicks a start signal to the Cooling fans. The Fan Relays send switched voltage to the fans, turning them on. Test the ECT Sensor for continuity when cold. Then get the car to normal operating temperature and test it again.

Heres a picture of the Relay Locations:

[hill8570]

Originally Posted by camry_jc

Yes, I have a digital multimeter.
Specific instructions appreciated.

Do this check when engine is cool:

Looking down from the passenger side of the radiator, at the bottom of the radiator just to the right of the coolant outlet of the radiator, there is a little connector connected to the coolant temperature switch. Disconnect it -- press in hard on the release on the right side of that connector, wiggle, and pull (don't pull on the wires -- that connector doesn't come off easy, and you don't want to rip the wires out of the connector). When the connector is off, check the resistance of the coolant temperature switch -- it should be basically 0 ohms (dead short) -- if it's not, you've found your problem (it's designed to "fail open", which puts both fans into high speed mode). As a couple others have mentioned, make sure the connector is goes on tight (clicks) when it is put on -- the whole system is designed to put the fans into high speed mode if there is a problem.

[camry_jc]

guys, awesome directions. Going to have at it tomorrow and will report my findings back here.

[camry_jc]

Originally Posted by hill8570

Do this check when engine is cool:

Looking down from the passenger side of the radiator, at the bottom of the radiator just to the right of the coolant outlet of the radiator, there is a little connector connected to the coolant temperature switch. Disconnect it -- press in hard on the release on the right side of that connector, wiggle, and pull (don't pull on the wires -- that connector doesn't come off easy, and you don't want to rip the wires out of the connector). When the connector is off, check the resistance of the coolant temperature switch -- it should be basically 0 ohms (dead short) -- if it's not, you've found your problem (it's designed to "fail open", which puts both fans into high speed mode). As a couple others have mentioned, make sure the connector is goes on tight (clicks) when it is put on -- the whole system is designed to put the fans into high speed mode if there is a problem.

Hello, I did the test, and i think the sensor is good. At cold start, it was showing 0 ohms. as the engine heated up, it went to 1 then 2 (I manually disconnected the fan to get it hot), then, when i plugged the fan back in and idled it down, the motor cooled and i observed the reading return to 0 ohms. all during the operation, I had my multimeter connected using aligator clips and it was set on 2000 ohms.

I'm declaring that part "good" unless ya'll think I flubbed up the analysis.

[camry_jc]

Originally Posted by houra

1. CHECK COOLING FAN OPERATION WITH LOW TEMPERATURE (Below 83°C (181°F))
(a) Turn the ignition switch ON.
(b) Check that the cooling fan stops.
If not, check the cooling fan relay and ECT switch, and check for a separated connector or severed wire between the cooling fan relay and ECT switch.
(c) Disconnect the ECT switch connector.
(d) Check that the cooling fan rotates.
If not, check the fan main relay, cooling fan relay, cooling fan,
fuses, and check for short circuit between the cooling fan relay
and ECT switch.
(e) Reconnect the ECT switch connector.

2. CHECK COOLING FAN OPERATION WITH HIGH TEMPERATURE (Above 93°C (199°F))
(a) Start the engine, and raise coolant temperature to above 93°C (199°F).
(b) Check that the cooling fan rotates.
If not, replace the ECT switch.

Few other observations:
- Ignition on, motor not running, engine cold, fans spin
- ECT unplugged, ignition on, fans spin

What next?

[houra]

Originally Posted by camry_jc

Few other observations:
- Ignition on, motor not running, engine cold, fans spin
- ECT unplugged, ignition on, fans spin

What next?

so there is problem, it should not spin

[houra]

REMOVE ECT SWITCH
(a) Disconnect the connector.
(b) Remove the ECT switch.
(c) Remove the O–ring from the ECT switch.
INSPECT ECT SWITCH
(a) Using an ohmmeter, check that there is no continuity between the terminals when the coolant temperature is above 93°C (199°F).
If there is continuity, replace the switch.
(b) Using an ohmmeter, check that there is continuity between the terminals when the coolant temperature is below 83°C (181°F).
If there is no continuity, replace the switch.
REINSTALL ECT SWITCH
(a) Install a new O–ring to the ECT switch.
(b) Install the ECT switch.
(c) Connect the connector.

[houra]

also to check fan relay, you can change it with horn relay.
i hope it helps you