Disco 2 Fuel Filter Water Sensor

evening all, I have a 2000 Defender TD5 and 2003 Discovery TD5 and in neither of them will the “water in filter” light ever illuminate, not even when the ignition is switched on during the bulb checks. My mate has a 1999 Disco and his is the same, but some do seem to have it.

Is it something that is programmed to the ECU? I have never seen anything about on either of my diagnostics.

Seems odd that some seem to have it and not others

Do you physically have the sensor connected on one of those vehicles?

sierrafery said:

Do you physically have the sensor connected on one of those vehicles?

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No I thought it was wireless?

Lol. Yes the sensor is connected, and stupidly I’ve replaced the sensor twice!

I asked cos there are modells without that sensor from factory especially facelifts and the warning is not there on those.... if the vehicle was fitted with it the warning should come on for self test unless there is a wiring issue or the instrument pack set to petrol in the BCU ... the glow plug lamp is working?

sierrafery said:

I asked cos there are modells without that sensor from factory especially facelifts and the warning is not there on those.... if the vehicle was fitted with it the warning should come on for self test unless there is a wiring issue or the instrument pack set to petrol in the BCU ... the glow plug lamp is working?

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Yes the glow plug lamps work on both of them. The D2 is a facelift, the Defender is a 2000 TD5. Maybe they didn’t have it, but I’d have thought if they didn’t have it there would be nowhere to plug the sensor in

Read again what i wrote if you didnt get it... if the sensor is there from factory the warning should work too, unplug it and make a bridge in the plug between the black and the orange/green wires see if it comes on then or not

sierrafery said:

Read again what i wrote if you didnt get it... if the sensor is there from factory the warning should work too, unplug it and make a bridge in the plug between the black and the orange/green wires see if it comes on then or not

Click to expand...

Ok thank you, will do that. I don’t know if the sensor was there from factory or not as neither were bought new, but the wiring socket is

On the defender the two outside wires are cut off and the middle one is connected to the plug. On the discovery all the wires seem to be the same colour, but the paper clip did get quite hot! So I don't know if either are meant to have it or not. They both have the plugs, but neither of them illuminate the warning light during the bulb check.

Something is not right then.... though it's not important enough to bother with it, mine had it and i got rid of it cos the sensor cracked and i didnt want to buy another, as long as the filter is changed twice a year like i do that sensor is useless IMO, even worst, if it fails with a short circuit it can mix up the fuel supply cos it's on the same circuit with the pump(i'm speaking only about the D2 here) the OG wire goes to the warning lamp

I'd concur with @sierrafery. The fuel filter often gets forgotten, largely because of its location. I change mine at the annual service, along with all the other filters and engine oil change.

I do change them fairly regularly, certainly more often than annually. I can only assume they didn't have it from new but the plugs are left on the loom to save costs. I bridged the orange/green and black wires on the discovery and the paperclip got very hot very quick. I'll just leave it all as it is, hasn't done any harm so far.

My fuel filter warning light flickers occasionally, I changed the filter a few months back but it still flickers as it did before. Is that because the sensor is dodgy or is it actually doing it's job?

It's overduing it's job IMO... they become too sensitive in time