A/T Light stays on...

Hi guys -

I posted earlier this week about a leaking transmission. I've got an 89 Montero, 125k.

The A/T light had been coming on after driving about 30 minutes. I put it in Park a couple of times and waited a looooong time for the light to go off. (20 minutes is a long time to sit in a grcoery store parking lot).

The last time the light came on, I was about 2 minutes from my house, and it was late. I turned off the engine instead of sitting in park. Now the darn light won't go off - it is on from the minute I start the car.

I topped off the ATF - it took about 2/3 of a quart to get to the "hot" range notches, checked when the engine was fully warmed up. Even after putting in the fluid and idling for a half-hour, the light it still on.

I know the A/T Temp can't possibly be at 300 degrees after a night out in the cold, so the sensor is either busted or it is telling me something else is wrong. Does the A/T light mean anything other than "Your trans. fluid is too hot right now"? Could it mean "Hey dummy, you need to have this looked at"?

I live in the Los Angeles area; it has been raining like crazy here (Hard to believe, I know). Every time the light has come on, it has been wet out. Off-Roader wrote in this post that his temp sensor was messed up by the wet weather.

Anything I can do to check this out? Is 2/3 quart very much transmission fluid? In my last post, you guys speculated that the A/T light was coming on because there wasn't enough fluid - would that be low enough to cause a problem? Or could the problem be the sensor all along? Or something else?

Thanks, I appreciate your advice,

- h

Sounds like the sensor is bad to me. You should have a look to see where the fluid is leaking. That's not a huge amount of fluid depending on how long it has been since it was last filled, but it's enough to cause major concern - at least keep an eye on it to see the rate of leakage because it shouldn't be leaking at all. and if it suddenly blows a seal on the highway you may not know it until it's too late - particularly with a bad sensor.

Frank

Check the hoses for leaks and try to track it down. The sensor will cause the light to stay on, is about about $15 from the stealer and is a 10 minute job. Good Luck!

Carlos

Stickied at top of page: Mitsubishi 4x4 Frequently Asked Questions for New Members

DougB -

I did see the sticky; I was mostly wondering if the light-always-on means the sensor is bad, no matter what, or if it could mean something is wrong.

I guess it always means the sensor is bad?

-h

Hoody,
The sensor is usually a good, cheap, and easy place to start. Like offroader said, water and electric connections don't mix. If the filter has not been changed (that you know of) you may as well do that as well. DougB did a very good write-up with pics on the filter change. Good Luck.

Carlos

A/T Temp light on all the time means that the sensor is busted. Keep in mind, if you drive the truck with a busted sensor, you may still be overheating your transmission and not know it!

<img src="/forums/images/graemlins/kewl.gif" alt="" /> Thank you!! <img src="/forums/images/graemlins/smile.gif" alt="" />



I did? OK, probably on another post.

Hoody,

I've found on mine that is sometimes gets wet which shorts out the sensor temporarily. Usually after things dry, the sensor works fine again. Do let us know what you decide to do and how you make out on the repair.

Ray
AKA Off-Roader

I am here in Southern CA and with the heavy rains, my light keeps going off and on. I had it parked for the day and when I went home, within one minute the light came on. I would say replace the sensor and/or make sure the old is sealed properly.

Actually talking about the same situation.

Here

I have no idea how I remembered that, and it probably makes me look like a freak. <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/lol.gif" alt="" />

Carlos

That's exactly the sort of situation I'm having. Thanks for digging it up! I wonder why I didn't find it when searching.

This morning, the light was off (finally - it must have dried up). After driving two miles on the freeway behind a semi in the driving rain, the light came back on. Water? Temp? Evidence points toward water. I'll get the sensor checked out tomorrow. Its a lot cheaper than a transmission...

- h

<img src="/forums/images/graemlins/zombie.gif" alt="" />

Dude, that was 8 months ago... let it go... <GRIN>

Well I'm glad to see I'm making an impact. <img src="/forums/images/graemlins/cyclops.gif" alt="" />

Actually, I only wish my memory was that good with everything. Funny thing is, I'll remember minutia details on the wierdest things but on other things, nothing but a haze or blank page. <img src="/forums/images/graemlins/lol.gif" alt="" />

If you decide to change the sensor be prepared to catch the tranny fluid that drains out when it's removed. Fluid runs in the lines at the bottom of the sensor and that it how the temp is taken. This may have been common knowledge to some but caught me by surprise and I had a small puddle to clean up. <img src="/forums/images/graemlins/scared.gif" alt="" />

Carlos

Cheap cat litter is your friend.

Anybody have a photo of the location? I know it's supposed to be on one of the return lines on the passenger side of the tranny, but I've looked a couple times and didn't spot any likely candidates. What size wrench does it take?
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95 SR