Can someone please explain in simple terms what this thing does. Apart from that is having the ability to stop a V12 in its tracks and present itself as a fuel pump on its way out, marginal fuel filter, or coils, or ignition amplifier or FPR 1 or FPR 2..............

Joking aside, what does it do? I thought the auxiliary fan was triggered by the unit with the 2 spade connectors at the front of the engine.

ltem I in question coolant temp sensor From thermostat housing on left side of engine

Thankyouverymuch

 

That is the OE CTS, AKA Coolant Temp Sensor.

It is the PRIME sensor for the Fueling ECU in the boot.

The White top was the original unit, replacement were Black or Blue topped, BUT, they are not Jag specific. Down here the Aussie GM and some Fords used the same thing, and the ECU is happy with them.

What they do,

Oh dear, they keep the ECU alive, along with other signals of course.

Putting it simply:

Running V12, unplug the CTS = Dead V12, its that simple.

NOTHING to do with fans. That critter is in the water pump Inlet elbow where the bottom hose attaches.

 

ahh, so its like a sexy electronic mixture screw.

Many thanks Grant. lm going to put new ones in and keep one old good one as a spare.

 

Fueling requirements are a lot different depending on engine temperature. So if your sensor reading is not accurate, well, you already know what happens.