Thread: Temp sensor ECU

Originally Posted by byron

Sorry, but you're wrong here.....on a D1 V8 the sensor which tells the ECU the coolant temp. and thus allows ECU to control amount of fuel coming in is the one located on valley cover/intake manifold on passeger side and a little in front of to the side of Thermostat Housing!

UPDATE: THIS ABOVE APPLIES TO Early (pre-update) D1's

See UPDATE Given !

I do not have direct knowledge of the update Serpentine 14 CUX , but I know about the vbelt 14CUX and the Thor.
For the v belt 14CUX the diagram from the manual is wrong or should I say incomplete.
There are three sensors on the old 14CUX
1 for the gauge which has a single wire.
One for the ECU situated behind and to the right(drivers side) of the thermostat housing.
and one for the fans ON the thermostat housing.
The ECU sender has an injection plug on it with 2 prongs, and a wire holder.
Now the Thor engine uses a similar sensor but with 4 prongs.
I understand that on the 38A pre Thor engine ( GEMS) the 4prong plug is used but only using 2 terminals.
SO it is pretty unlikely to me that the two prong plug on the thermostat housing is used on the Serpentine 14 CUX for the ECU.(but I could be wrong!!!)
Look for a sender , situated on the front of the manifold with an injector plug on it. An injector plug is quite distinctive as it has a wire holder that has to be squeezed to release the plug.
The manual gives the resistance but from memory it should be less than about 800 Ohms at 80c. Mine if I recall correctly is about 300 Ohms at operating temp of 82C.
Higher values can be just a dirty plug, or if the thermostat is opening early and the engine is under 80C.
Regards Philip A

I think Philip's figures are about right.

Figures I have recorded for the ECU coolant sensor are............................

0c 5700 - 5900 ohms.

80c 300ohms.

Hot Engine 200 ohms.

Mine "appeared" to be shot, so I replaced it with a new one from Coopers, but still wasn't sure, as at the time I appeared to have other problems all of which are now rectified & 'she' runs like a Swiss watch now. The ECU sensor "appeared' erratic for whatever reason. It was just one of a few items replaced or repaired.

This is what I have been working off

Confusing.
According to my info, ladas, the thermostat in front of the thermostat housing on the 3.9 is for AC fans only.

The ECU Coolant Sensor is on the head adjacent to the Temp Gauge thermostat.

[Manuel mode on] Eeez possible Manual is wrong, Meeester Fawlty?[Manuel mode off]

Originally Posted by 4bee

Confusing.
According to my info, ladas, the thermostat in front of the thermostat housing on the 3.9 is for AC fans only.

The ECU Coolant Sensor is on the head adjacent to the Temp Gauge thermostat.

[Manuel mode on] Eeez possible Manual is wrong, Meeester Fawlty?[Manuel mode off]

Confusion may have been solved - it seems the difference is between the MPi (MEMS) system and the MFI (Hot wire MultiPort Inj)

The sensor, location and description I have given is for the MFI, not the MPi .................

So I guess everybody is correct.........depending on which system you have.

Or in fact the SFI system, which I understand wasn't introduced in AU on the D1...........

................but who knows ???

The sensor, location and description I have given is for the MFI, not the MPi .................

So, are you saying the Thermostat on the front of the housing is AC fans ONLY or a combination stat now?

I'm confooooosed.