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Why would an AT Oil Fluid light come on?

1770 Views 18 Replies 6 Participants Last post by  Andrew
Ever since I have done my Split Second Programmable Map install i sometimes get an AT Oil light temp flashing in my face. when i check my oil it looks fine. i check my temp gauge and it looks great. :confused: :confused:
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???? good question. Maybe you should temporarily unhook the SS MAP and see if the problem goes away. Usually the light is for trans oil temperature.
Yeah. turbo's on Auto cars have been known to overheat the trannies. Not a good thing. Make sure that you are not overheating the fluid!

Eric
hmm weird...andrew where is your tranny temp guage at?? i wonder if there is a sensor in the actual pan or in the fluid exahust port right off the torque converter(where it's the hottest).
im not exactly sure. i sent it over to ISR to have it done... it never goes over 200 though
well depending on it's location could mean alot....ask them where they put it.
well its gotten up to 200+ before and it has NEVER flashed before. this has ONLY happened since the SS Map. and it doesnt even happen often. just sometimes when i floor it itll come on and this is when my temps are 125-150.

i remember there is a special "code" you can put do with a 4EAT to flash the AT oil temp light and however many times it flashes is whats the problem. it doesnt ALWAYS mean the at oil temp correct?
weird...i dunno what to tell ya.
I think....

Be careful with that Tranny...I will guess that its life is being reduced exponentially at this stage...And the light only comes on if its too hot and it won't come on at any other time...Change your fluid for something more Hi-Performance...And get a Tranny Cooler...

Zee
guys, the tranny has seen way higher temps than this and has NEVER had a problem. and i have NEVER heard of ANYONE having problems at only 5psi of boost. the 4eat can take a shit load of power. i do not abuse it. i dont do N drops, and i dont sit with my foot on the gas and brake pedal all day. this happens ONLY under WOT and it comes on right away before the tranny has alot of time to heat up a great deal.


but i have been planning on changing the fluid to some redline auto tranny fluid. there is a "trick" that can be performed and the tranny will tell you what the problem is. the at oil temp light doesnt always mean that its the oil. it could just be a bad ground (could have came loose when i was installing the SS Map).





oh yeah and lets add this little tidbit....depending on the fuel map i use, it goes off. with this map that 8c has given me for off boost, it comes on. before that, i had it so it would never come on. and before that between my "tuning" it would go on and off depending on the A/F (at least thats what it seemed). i have no idea why my fuel map would have effect on it. ive driven the car HARD with other fuel maps taking it past 100mph in WOT and along some tough roads and it never went off. but then just getting to 40mph in WOT it likes to go off.
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weird...if i knew exactly how it related to the AT TEmp sensor i could prolly be of more help to you andrew...how is nick's map working otherwise?? the dudes a genious.
offboost works better than my map (aside from the AT oil temp light). like i told nick, i dont want to say that its the best map around yet becuase i havent been able to test it yet. but so far its worked excellent. on boost needs to be adjusted (i set it myself), but nick also brought up a timing issue which i cant do anything about (retard/advance)...no itc...


you know what? i would bet 100 bucks that if reload my map the AT oil light would not go off...then load his and it would. im gonna eventually call up subaru and ask them what could have happened and how the TCU is hooked up. if they cant help me looks like its time for some electrical tape.
Andrew - How were you EGT's with your map? I know you said mine were coming up to around the 1600° area, but wonder what it runs with yours.

Also, if your exhaust is near the stock AT oil temp sensor, I think there might be a possibilty that it is helping out the problem. Have you tried running with an OBD-II scanner in the car and watched the trans oil temp? Maybe if you can relate it to the EGT's somehow, then you'll know what is up.

Jeremy - You should have seen some of the math I was doing to figure out voltages... LOL I felt like a retard I haven't done this type of stuff in so long.
i would assume so since it's been almost a decade since you were in school...haha j/k

yeah i am on the same bias as nick, try locating the factory sensor and if it's near the exhaust place a heatsheild inbetween the exaust and the sensor...in certain spots they have a 400 degree F difference in temp with just the addition of a alumnium heatsheild.
my EGTs maxed at 1500 on WOT runs with my map.


anyways guys...i think i found the problem. i bumped this thread on the iclub (http://www.i-club.com/forums/showthread.php?s=&postid=1284567) and inpreza kid said this:
when i put in a afc in my auto My00RS i got a flashing AT oil temp light. it went away after i reconnected to map sensor wires. from what i know the TCU reads the map signal too. first thing i would check is the wire map wire connections.
:confused:
Hmmmmm... I just find it funny that it does it with my map and it doesn't with yours. VERY strange...

Also, theoretically the output from my map should be VERY near (within about .05v) the output of the stock map sensor.

Does the auto trans perhaps have a load sensor (like a MAP sensor for auto tranny fluid pressures or something... I don't know auto's too well) in it as well? Maybe it is cross checking them and finding a major difference, but that still wouldn't explain why it goes off with my map and not yours... hmmmmm...
well the tranny has to be able to calculate engine load to push up the line pressure so that the clutch packs will hold. So i would assume it is someone tapped into the MAP sensor somewhere.
Hmmm....

You knowwwww, I bet $100 there is a pressure sensor in the Tranny and its setting off your light...In the Automatic Transmission, Alot more goes on than just switching gears...Pressure from the throttle position is being recorded by sensors and sent to the ECU to deliver appropriate Ignition Timing and Fuel Rate...Theres gotta be a program to sense one of the many different changes your N/A RS goes thru with Turbo..

Check the manual...The ECU can't just throw a light...Theres a sensor that is making the light come on...unless you have a short somewhere thats a result of you tinkering...

Zee :nuetron: :nuetron: :nuetron:
8Complex said:
Hmmmmm... I just find it funny that it does it with my map and it doesn't with yours. VERY strange...

Also, theoretically the output from my map should be VERY near (within about .05v) the output of the stock map sensor.

Does the auto trans perhaps have a load sensor (like a MAP sensor for auto tranny fluid pressures or something... I don't know auto's too well) in it as well? Maybe it is cross checking them and finding a major difference, but that still wouldn't explain why it goes off with my map and not yours... hmmmmm...
i dont know if i said it but it comes on only under WOT.
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