A440 Transmission Temp Light

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Hi

New to the site and have not been able to find a thread with my problem.

I have an 89 FJ62 with an A440 tranny. I recently had a complete rebuild and have installed a cooler.

What I am experiencing is the tranny temp warning light comes on when cold and stays on for about 2-3 minutes. It only comes on early in the morning when about 40 - 50 degrees. When I get off work in the afternoon, 70 - 80 degrees, it doesn't come on at all.

I am planning to install a gauge, but for now just rely on the light.

Is it a bad sender? Any ideas would be greatly appreciated. :cheers:
 
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I should also mention that I am not getting any other wanrning lights, only the transmission light.

Any ideas?
 
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I had close to the same issue after my rebuild and could not figure out why the light was coming on. Mine stayed on the whole time from a cold start but never slipped a gear or anything funky with shifting. Someone suggested I check my alternator for proper voltage and it was a little low but not bad. No one could figure it out. Then one day it just went out. I have no idea why but the light bulb still works. I feel like it just reset its self.
 
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To add info to the previous post; the parking brake light comes on as well if the alternator is going. Your temp light is connected to a sensor (thermocouple). Your computer reads the resistance acorss this sensor and determines if the light should go on. Maybe you need to pull the sensor and check it per the FSM? I don't have my FSM with me so I cannot look at the schematic to see what else would affect your light.

If your parking brake light is coming on to then its your alternator but you mentioned no other lights.
 

Max.Powerzz

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Silly question, but have you checked your fluid levels? Too much or too little makes them very sensitive (in a loving, caring kind of way).
 

Max.Powerzz

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To add info to the previous post; the parking brake light comes on as well if the alternator is going. Your temp light is connected to a sensor (thermocouple). Your computer reads the resistance acorss this sensor and determines if the light should go on. Maybe you need to pull the sensor and check it per the FSM? I don't have my FSM with me so I cannot look at the schematic to see what else would affect your light.

If your parking brake light is coming on to then its your alternator but you mentioned no other lights.

X100...ask me how I know.
 
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Temp light still comes on when cold. Stays on for about 30 seconds after I start driving. Has not come on when hot since I installed the cooler.

Any idea how to check the sensor?
 
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Someone with a FSM in their hands can confirm but I believe you have to pull it out and put it into boiling water and check it that way? I forget and would have to reference the FSM.

If you do not own a Factory Service manual (FSM) then you need to buy one. They are invaluable to tracing and diagnosing problems.
 

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