View Full Version : need help identifiying sensor

10-18-2006, 01:35 PM
hey guys, i wanted to find this out on the BGB but most of hte links on the electrical section are dead

so on the little xmas tree that comes out the side of hte block (on the right when looking at the engine bay) there are all the water temp sensors this one is the one closest to the block on top, with a single wire that comes out and goes to the loom and has a long square connector, unfortunately due to it being old and brittle it broke while putting the engine back in today, just want to know what this sensor does to see if i can use the car without it for the time being, i had a look at my box of mr2 parts to see if i had a spare but unfortunately it's missing on the mr2 equivelent sensor xmas tree,

thanks for the help

Matty :)

10-18-2006, 04:19 PM
I think you are referring to the oil pressure sensor plug? Its more rectanguler than square and connects to the round oil sensor. If thats the plug you are are missing you should be able to drive the car without it.

Luis C
10-18-2006, 07:00 PM
If the Oil Press Sensor signals is missing or disconected the OIL light would go on in the dash

91 celica st
10-18-2006, 09:58 PM
i believe hes talking about water temp sensor, he said one wire

10-18-2006, 10:36 PM
You have a 90/91 right?
It should be a coolant temp switch for the ac.
A pic would clear it up real quick....

I believe I actually have one, though it's used and I don't know if it still operates correctly.
And you're in Aust. :D

10-19-2006, 12:51 AM
yeah i really don't think it has anything to do with the oil, it's in the water sensor clustor out the side of the block, it's amongs the water temp sensor for the cold start injector etc,, i'll get u guy a pic, but air con sounds about right, thanks man

i'll take a piccie and see what u guys think,
just a dumb question why exactly does the air con need a water temp sensor??


Luis C
10-19-2006, 01:11 AM
If the water temp goes above tolerable levels the ECU shuts down the A/C compressor to relieve some load off the engine

10-19-2006, 03:13 AM
ahhhhhh i see! so will it pull an error code if the sensor is fucked? coz number 1 i hardly use my air con and number 2 i have a good quality water temp guage i watch like a hawk :P

10-19-2006, 01:35 PM
ok so here is the sensor i'm talking about (the one i'm pointing at obviously!)

is that the air con one u were talking about??


10-19-2006, 07:49 PM
. the oil light will not come on if you disconnect the sensor, it will stay off. and no codes will be thrown. The way it works is when it sees oil pressure it opens the circuit, when it doesnt see enough it closes the ciruit lighting up the light, the light will come on if you ground that wire other wise nothing will happen. the sensor you have broke, is the same one i also did while putting in my engine, i just replaced it with my water temp gauge sensor. No negative side effects of having it off, so there no need to replace it, unless you want the ac kickup feature.

10-19-2006, 11:25 PM
Yep, that's what it is.

The oil pressure guage doesn't cause a CEL because it has nothing whatsoever to do with the ECU.
It is only for the instrument cluster.
Just like the coolant temp sensor for the guage.

10-19-2006, 11:43 PM
sorry guys but what does it have to do with oil ?? only water goes into that sensor cluster,, i'm not debating your knowledge, maybe i'm just misunderstanding you,,

but bascially i just wanted to know if i needed it and it seems i don't so thats sweet.

thanks guys, was a great help :)

10-20-2006, 12:24 AM
It has absolutely nothing to do with oil. :)

Luis C
10-20-2006, 03:31 AM
. the oil light will not come on if you disconnect the sensor, it will stay off. and no codes will be thrown.

I was talking about the Oil Pressure Sensor, the OIL light will go on if you disconect the wire from the sensor (or at least in my car it does), and no, there is no funny wiring around

10-21-2006, 10:55 PM
all good , i took the car for a drive n stuff it's all running well, thanks for the help guys