Coolant sensor

[corkie]

Hi I replaced this with a genuine one from cotswold 2 month ago , now the light on the overhead check panel has come on again surely it can't be the sensor again?
Any ideas please the plug and wiring look ok

[paultv]

Do you mean coolant level sensor? The socket that plugs into the sensor gets very corroded..clean its connections as best as you can...wiggling the plug will tell you if this is the culprit!

Paul

[Brianmoooore]

Wire to the plug also can break internally, right where it enters the plug. If you short the two buckets of the plug together with a piece of wire, the LED should stay off. This will show if it's the wiring or the sensor at fault.

[corkie]

Great I will try this I've got new plugs somewhere, thank you

[Brianmoooore]

Don't go diving in and replacing things without testing and determining exactly where and what the fault is before changing anything.
Unlikely, since you bought it from BMW, but there is an almost identical (slightly different length) sensor in existence, which works in the opposite way to the one in your tank. This will leave the LED off when the coolant is low, and put the light on when the level is correct.
I discovered this after once being supplied with the wrong part by ECP.