sensors...

[mike561]

I need to know where the temp sensor is on my car, i was driving around today and it seemed the temp guage diddnt move at all. another thing is i'd like to know where the service engine light sensor is as well, or is its in with the computer? i never see that service engine light come on at all even when i first start the car, im thinking the little bulb may be bad also.

[silicon212]

Temperature sending unit (this is what you want, it's what runs the gauge) should be located on one of the cylinder heads, most commonly on the left side between the spark plugs for cylinders 1 and 3 - but could be on the passenger side between 6 and 8.

Don't confuse this with the coolant temperature sensor - this is on the thermostat housing and has two wires (a black and a yellow) and is used by the computer to determine engine operating temperature.

[mike561]

Ok, what about the check engine light not working too? it never even comes on for a couple of seconds when you first turn the key, im thinking the bulb may be bad too.

[silicon212]

Change the bulb. The computer won't work properly with the bulb out.

It should 'bounce' or 'flicker' when you first turn the key to ON - it should light for a split second, go out for a split second, and come back on until you start the engine.

[mike561]

It doesnt come on at all, so im geussing the bulb is totaly dead then. i know what you mean though about it going on and off before the engine is turned on.

[mike561]

Ok nevermind what i just wrote last, i had the instrument panel all taken apart today and the check engine bulb was removed, so there is no bulb in there at all. i can see what kind it is though, the little ones with the plastic base that screw onto the copper contacts. i checked advance auto parts but they dont have bulbs like that, where would i find a bulb like that???? im geussing the dealer would be the only place, no luck online as usual for me.

[silicon212]

The light bulb is a standard 194 indicator bulb. The plastic base is actually a part of the dash, the bulb plugs into it and it in turn twists into the dash. If you don't have the twist base, you will need to obtain one for it.

[mike561]

yeah ive seen the bulbs at the store but unfortunatly i have no base for it. im planning on going to the salvage yard this weekend so hopefully i can find one there, if not ill just have to get it online. i found a REALLY good auto parts site if anyone's herd of it, its www.rockauto.com

[silicon212]

Originally Posted by mike561

yeah ive seen the bulbs at the store but unfortunatly i have no base for it. im planning on going to the salvage yard this weekend so hopefully i can find one there, if not ill just have to get it online. i found a REALLY good auto parts site if anyone's herd of it, its www.rockauto.com

If you put the light bulb back in and it stays lit up constantly, I'd check all of the fuses for the ECM - there are two on the fuseblock, one is labled "ECM" and is hot at all times and then there is IGN-ECM which is hot when the key is on. If this fuse blows, it will cause the light to come on and stay on and the computer won't work. There's also a possibility of the light driver module, which is typically a bluish colored 'socket' above the dashboard with a printed circuit board plugged into it - this can also fail and cause the light to come on constantly even with nothing wrong with the ECM. It could also cause it to not come on, ever, so check into that as well.

[mike561]

ok ill let you know what happens. im going to have the mechanic plug it into the computer cause im sure it might even have MANY codes if the light comes and stays on.