Wanted to document a fix on my 99 LC, since I couldn't find much information out there about it.
Got a " transmission fluid temperature sensor A circuit fault", P0710, code. Able to clear it and drive without a code; checked AT temp with infrared gun and it was normal. This code is for a "fluttering" temperature sensor resistance, high and/or low. Clue for me was getting this code on rough roads; suspected a loose connector.
What I found was a loose connector and connector corrosion:
For 99 LC in the U.S., this sensor is located on the oil pipe (look above the front propeller shaft). I replaced the sensor but wanted to make sure the connector corrosion didn't happen again. I soaked the connector in PB Blaster for 30 minutes and soaked it again in contact cleaner to thoroughly remove any traces of PB Blaster. A little scrapping with a small screwdriver, and the connector contacts were much better. I added some dielectric grease to seal the connector:
Okay, here's where my true paranoia begins to shine. Even though the connector made a nice click and everything appeared okay, I added a "belt and suspender" arrangement of wire ties to make sure this connector stays in place. Not overly tight, just enough to keep this from backing out again. This connector is in a bad place for exposure to road salt, etc., so hopefully this will keep it from repeating in the future:
Note that this sensor location appears to have been changed to the valve body on later years. This affords much better protection for the sensor, but requires dropping the pan.
Hope this helps; any critiques welcomed. Seems to be working fine on my rig (40 miles of rough forest roads without an issue), but would welcome any input.
Appreciate all the work put into the forum. Has been a big help with my 99 LC. Over the last month, I have replaced the front diff, drive adapters, CV/axle on the DS, radiator, water pump/timing belt, rotors, bled brakes, etc. Getting the gumption up to finish the shocks (fronts were bad/rear are absorbing PB Blaster).
Got a " transmission fluid temperature sensor A circuit fault", P0710, code. Able to clear it and drive without a code; checked AT temp with infrared gun and it was normal. This code is for a "fluttering" temperature sensor resistance, high and/or low. Clue for me was getting this code on rough roads; suspected a loose connector.
What I found was a loose connector and connector corrosion:
For 99 LC in the U.S., this sensor is located on the oil pipe (look above the front propeller shaft). I replaced the sensor but wanted to make sure the connector corrosion didn't happen again. I soaked the connector in PB Blaster for 30 minutes and soaked it again in contact cleaner to thoroughly remove any traces of PB Blaster. A little scrapping with a small screwdriver, and the connector contacts were much better. I added some dielectric grease to seal the connector:
Okay, here's where my true paranoia begins to shine. Even though the connector made a nice click and everything appeared okay, I added a "belt and suspender" arrangement of wire ties to make sure this connector stays in place. Not overly tight, just enough to keep this from backing out again. This connector is in a bad place for exposure to road salt, etc., so hopefully this will keep it from repeating in the future:
Note that this sensor location appears to have been changed to the valve body on later years. This affords much better protection for the sensor, but requires dropping the pan.
Hope this helps; any critiques welcomed. Seems to be working fine on my rig (40 miles of rough forest roads without an issue), but would welcome any input.
Appreciate all the work put into the forum. Has been a big help with my 99 LC. Over the last month, I have replaced the front diff, drive adapters, CV/axle on the DS, radiator, water pump/timing belt, rotors, bled brakes, etc. Getting the gumption up to finish the shocks (fronts were bad/rear are absorbing PB Blaster).
