I own a 2001 Discovery Series II. Under normal driving conditionsthe transmission oil temperature light turns on. I had a transmission mechanic drain the fluid and replace with new. He stated that the fluid was dark, however, he did not seem to think after driving the vehicle and inspecting the transmission that I had transmission problems. I don't what is going on! Could it be I have a bad temperature sensor?Is it the oil cooler? Please help!! Thank You.

 

You can not completely change the fluid unless you flush, which I do not recommend. FYI. Does the light flicker, or is it on constantly? Could be a bad connection at the plug, or the sensor could be bad. I would check the connection first and clean the conacts.

 

okdiscoguy,

The light turns on after 10min. of normal drivingthen stays on constantly until you shut off the car.

 

You need to take your truck to a tranny shop, have them plug in and do a real time scan on the tranny operation to see if it is the tranny, a bad switch or a plugged up tranny cooler line.
Mike

 

I had a very similar problem with my 2000 Disco II.

It turned out to be a bad sensor. I had it in 3 times before they finally replaced it.

 

placek36
Had this problem with my 2000 LR Disco II.
This happened while I was pulling a boat trailer. Obviously I thought it was the tranny. The LR did not drive any differently, no shifting problems, no unusual noise, no indication of a slipping trans (high RPM for a specific speed in a specific gear).
Dealer tried everything. Connections etc. It just turned out to be a sensor gone bad.
Ed

 

I just bought a 99 disco I (89k miles)with the same problem. could you explain where is the sensor located ? is it inside the transmission body and is it possible to be DIY or just a dealer job?

 

I found the answer from a independent repair shop and thanks Disco Mike for his time and patient. I spoke to him by phone today. He is very knowledgeable andhelpful. the sensor for disco I is located in the transmission fluid hose near the radiator at the right lower corner with 2 wires connected.