4.8is Low Coolant level warning

[lynxjock]

Hi,

Having googled this to death I hope to find some help on here. The warning comes on before starting and after turning the car off, it does not stay on during driving. If you press the check function it come on. I have checked the level and there is definitely no loss of fluid. I have changed the sensor and still the same fault indications. Thinking it may be a faulty sensor I bought another one, still the same. The water bottle sensor is the same and I know that works fine, I have swapped those over and the sensors work fine in the windscreen wash water bottle but still the same error messages. I have bled the system and that was not the issue. The float seems to work fine, sucked out some fluid and float goes down, topped up and the float rises so I am pretty confident the level is correct. So know I am stuck, thinking it may need a new expansion tank as I read article about old V8 had faulty expansion tanks the fail internally (no leaks) but before I chuck any more money at it just wondered if anyone has any other ideas ?

[Jamine16]

That is strange.

I would suggest an air lock, but you've bleed the system.

Have you got any hardware to check the fault codes?

[Horizon]

It could be a wiring/ connection fault, if the sensor works of resistance, similar to a fuel gauge sender, a bad connection, or open circuit would cause the warning. You have eliminated the sensor so look to the wiring.

[lynxjock]

Wiring looks good, I think I might have to try a new expansion tank