Coolant Temp Sensor

**druu** · 14-09-2006, 07:07 PM

This is probably a once off, but I'll try anyway. I own a 94 Daihatsu Charade and I'm having trouble finding a coolant temperature sensor to replace the suspected faulty one in my car. Seeing as Toyota and Daihatsu parts are similar, I was wondering if anyone can confirm that the sensor below looks anything like a Toyota (4AGE, etc) one?

Thanks for any help..

**BeRad** · 14-09-2006, 07:22 PM

A thread size would be good and then can be matched to one of probably a million sensors with the same thread and sensor voltages.

have you testesd the suspected faulty sensor?

why cant daihatsu give you a replacement or one of many aftermarket shops... repco , supercheap etc etc

**Dale** · 14-09-2006, 07:41 PM

That's a two wire sensor, all toyota coolant temp senders I've seen are single wire.

**30psi 4agte** · 14-09-2006, 07:45 PM

get a Daihatsu one. there will prob be a resistance diff in the two

**druu** · 14-09-2006, 08:14 PM

Not sure on the thread size, but it's a size 19 hex. I was hoping to get an identical sensor. The problem is, the engine light comes on intermittently on startup, bringing up the code when I do an EFI diagnostic. Also, the car runs rich too. So naturally, I suspect the sensor as faulty. I've checked wiring continuity in the loom and also tested the resistance at the air temp sensor which matches the coolant temp sensor when the engine is cold. Bled the cooling system countless times also. One more thing, the car idles slightly lower than it should.

**druu** · 14-09-2006, 08:18 PM

BTW, it's temperature sensor, not sender. It's the signal sensor for the ECU. I've been quoted AU$80 for a new one from a Toyota dealer (genuine Daihatsu) but I'm not 100% sure it's the fault which is why I want to source a cheaper one.

**Dale** · 14-09-2006, 08:29 PM

Not 100% sure here but I think toyota sensor units are also often single wire, I've never seen anything with more than one wire going into it on any coolant related sensors on my toyotas. Correct me if I'm wrong anyone.

Do you have a DIY wreckers near you there? u-pull-it, pick a part, pick n payless etc?

**oldcorollas** · 14-09-2006, 09:10 PM

Originally Posted by druu

BTW, it's temperature sensor, not sender. It's the signal sensor for the ECU. I've been quoted AU$80 for a new one from a Toyota dealer (genuine Daihatsu) but I'm not 100% sure it's the fault which is why I want to source a cheaper one.

test the resistance of the sensor\sender vs temperature.
then compare against specs.
then decide if you need a new one

if it has a part number on it, or you can find a part number, go thru aftermarket, or cross-reference....

or borrow one from wrecker to check.

holden coolant sensors are like $20 or less

**Grega** · 14-09-2006, 09:19 PM

dale......ECU coolant temp sender units are two wire matey......look at the back of a 4AGE head and you'll see the blue thing on the back (coolant temp) or the brown thing (cold start injector time thingo or whatever its called)........the temperature sender (for the gauge is normally one wire)

the sensor (looks) similar to the toyota one but as stu above has said ; the resistance may be very different between the two.......which will still cause you problems - as the ECU will get the wrong signal and you'll end up running rich ect.

wreckers or even your local speed shop will be able to hook you up. in fact i think in the FAQ there is a list of different senders ect (though toyota only ones)

**Dale** · 14-09-2006, 10:09 PM

Ah yeah, I was thinking of the wrong plugs I think. Haven't ever played with a 4age though.. my mistake!

**Grega** · 15-09-2006, 05:19 AM

thats cool mate.
if you have a look on your celica you'll see the same things just above your gearbox also at the back of your 3S.
druu - try a speed shop matey. there may be non genuine ones which may do the same job which are cheaper.