OBD2 Engine Temp Sensor location & Desh Temp Location?? (1 Viewer)

Joined
Jul 30, 2020
Messages
8
Location
Israel
Hi All,


i have an interesting issue and wonder if someone here can help me with that?

My 1995 USA TLC80, 4.5 Liter 1FZFE engine with OBD-II system that works perfect.

few month ago my Dashboard Temp Gage stop working but the OBD2 still give live indication for the engine Temp.
I ordered a new Temp Sensor according to the Toyota part no. (from Rock Auto - replacement one) and installed it.

The Desh Gage is still not working...
the OBD2 working...

just to be sure, i removed the 2 connectors from the 2 sensors i was thinking as Temp sensors (no. 2 & 3 in the Picture),
The OBD2 still gives me a live indication for the temp...!!

I wonder if someone can help me by pinpoint where the OBD Temp Sensor located and where is the Dashboard Temp sensor located??


i used a Pic i found some time ago in this forum in one of the threads and mark on it the 4 sensors in the area
(i do not remember who is the Pic owner, sorry for that, as soon as i'll find him i will Credit him immediately)

Sensor 1 - ??

Sensor 2 - ??

Sensor 3 - ?? (this is the one i replaced already)

Sensor 4 - Knock Sensor
Temp sensor pic.PNG


Thank you in Advance for any information.

Rotem D.
IL
 
Joined
Jul 30, 2020
Messages
8
Location
Israel
Your problem is most likely the indicator in the dash.
How can i test it??
i looked on all the lines and componnects there,
it's all looks OK.
i need a way to connect to a power source and see if it's working or not before i start order new parts...

Thanks
Rotem.
 
Joined
Jan 5, 2017
Messages
2,713
Location
Charlotte, NC & Alexandria, VA
See schematic above.

Put 12V to it. If it moves, it's OK. If it doesn't, it's bad. This will not verify the temp calibration, but it will verify operation.

The engine temp sensor has a green power lead; you'll have to run that down on the engine side; I can't remember which sensor it is. BTW, the BR wire is a body ground.
 
Joined
Jul 30, 2020
Messages
8
Location
Israel
Hi All,


i have an interesting issue and wonder if someone here can help me with that?

My 1995 USA TLC80, 4.5 Liter 1FZFE engine with OBD-II system that works perfect.

few month ago my Dashboard Temp Gage stop working but the OBD2 still give live indication for the engine Temp.
I ordered a new Temp Sensor according to the Toyota part no. (from Rock Auto - replacement one) and installed it.

The Desh Gage is still not working...
the OBD2 working...

just to be sure, i removed the 2 connectors from the 2 sensors i was thinking as Temp sensors (no. 2 & 3 in the Picture),
The OBD2 still gives me a live indication for the temp...!!

I wonder if someone can help me by pinpoint where the OBD Temp Sensor located and where is the Dashboard Temp sensor located??


i used a Pic i found some time ago in this forum in one of the threads and mark on it the 4 sensors in the area
(i do not remember who is the Pic owner, sorry for that, as soon as i'll find him i will Credit him immediately)

Sensor 1 - ??

Sensor 2 - ??

Sensor 3 - ?? (this is the one i replaced already)

Sensor 4 - Knock Sensor
View attachment 2490348

Thank you in Advance for any information.

Rotem D.
IL



a small update,
the sensor that marked as no. 1 in the pic is for the Dashboard sensor,
it was disconnected in my car and now i need to find a new connector that will fit it (hope it will not be a big challenge here...)

so 1 last question still on the air...
where does the OBD2 temperature sensor for the engine is located??
 
Joined
Jan 5, 2017
Messages
2,713
Location
Charlotte, NC & Alexandria, VA
FWIW, the OBDII connector doesn't have separate sensors. It's just a link/port to connect to the sensors that the ECUs use. If you've found the coolant sensors (there are two, one for the gauge and one for the high temp shutoff circuit), you have found them all. IIRC, the gauge sensor is near the oil filter and the shutoff sensor is up near the distributor.
 
Joined
Jul 30, 2020
Messages
8
Location
Israel
FWIW, the OBDII connector doesn't have separate sensors. It's just a link/port to connect to the sensors that the ECUs use. If you've found the coolant sensors (there are two, one for the gauge and one for the high temp shutoff circuit), you have found them all. IIRC, the gauge sensor is near the oil filter and the shutoff sensor is up near the distributor.

Hi Malleus,

first of all thank you again for all your answers.

about the OBD2 Temp sensor,
i was sure as you there are only this 2 (1 Wire for the Desh Gage and 2-wires for the OBD2 ECU Unit).
however,
all 3 connectors were disconnected (1, 2 & 3 from the above pic) but the OBD kept giving me readings for the Temperature,
on top of that, the readings were logic to the status of the engine...
so i wonder what i'm missing here...??

Rotem.
 
Joined
Jul 5, 2017
Messages
1,511
Location
Israel
FWIW, the OBDII connector doesn't have separate sensors. It's just a link/port to connect to the sensors that the ECUs use. If you've found the coolant sensors (there are two, one for the gauge and one for the high temp shutoff circuit), you have found them all. IIRC, the gauge sensor is near the oil filter and the shutoff sensor is up near the distributor.

@Malleus the question is where is the temperature sensor that feeds the ECU?, it is not the Dash sensor!
 

Users who are viewing this thread

Top Bottom