hi my name I kim I have a landrover disco II 2001. it has ben very good to me and now its making me nus. the transmission oil emp lite is going on after say 10 mile o driving. I changed the gear box fluid and changed tranny fluid which wasn't burnt, the car runs good. no tranny issues. im toldit could be sensor but what if the sensor is actually working and the tranny temp is hi. what does that mean for the car and why is it? what should I do?

 

you need to have someone read "in real time" what the trans. temperature is when the light goes on. I think some of the standard OBDII readers can do that.
That way you can tell if it is a defective sensor or if it is really coming on for a reason.

 

I believe that on this truck, there are two sensors, one for transfer case can get connections gunked up, and ground out, turning on light. These "idiot light" sensors just ground out to turn on lamp, so even a cut place in wiring harness can do that, and I don't think the OBDII gets these signals. If they did our Ultra Gauge worry warts would be watching that too.

 

I guess you will need someone with a Hawkeye or bester test equipment to check

 

Or, replace the sensor, being that it is somewhat common to have them fail.

 

The sensors are "normally open" and "short to ground" to make the light turn on. So you could unplug one sensor, repeat the test drive, and narrow it down to which is providing the undesired signal. Attached are photos of both sensor locations.

Obviously, the one mounted at radiator would be transmission fluid, and you should take this opportunity to examine the AC condenser, tranny oil cooler, and main radiator for mud, grass, trash, etc. that could be blocking the fins and reducing cooling. Your dash heat gauge is about useless in this respect, it is programmed to point at 50% from about 130 - 240 F. But an OBDII live data check of coolant temp could also be indicated.