A/T Oil Temp Light - Advice... (2 Viewers)

[AK Wes]

So, for some reason I decided to drive my Land Cruiser as my commuter to work this morning..... Not my usual daily driver, but it has been raining A LOT lately and I'd rather take the Land Cruiser through all the road construction/potholes over my daily driver BMW X1. Anyway, I finish my 30 minute commute to the office and when I put the Land Cruiser into park the A/T Oil Temp light comes on. NOOOOO!!!! Definitely the last warning light I would like to see pop up.

I had to drive somewhere at lunch time ~ 5 miles away and relatively low speeds 25-35 mph and the A/T Oil Temp light keeps dimly appearing and disappearing. By the end of this short drive it is solid red. I go to my appointment for about an hour and a half, then it does the same thing on my commute back to work. I checked the trans fluid in the parking lot and nothing looks out of the norm, and it feels just slightly warm to the touch.

I am planning to drive it back home and park it in the garage in an attempt to diagnose the issue. Does anyone have any advice on where I should start? Also, is it a bad idea to drive it back home ~30 minutes away and should I be looking at bringing it to a transmission shop?

I haven't heard any odd noises, nor have I experienced any issues shifting.

Any advice is greatly appreciated!

Thanks

 

[TheForger]

Do you know if the fluid has ever been changed in your transmission? Have you noticed any spots where you park or fluid on your undercarriage that could indicate a small leak? I notice you have a 2000 LC so that means you have the trans dipstick. Can you wipe it on a paper towel and see what color it is and how it smells? It’d be great if you could get your hands on an OBDII reader like the ScanGauge II that allows you to monitor the temp in realtime. That would let you be able to see if the AT temp is abnormally high, or if it isn’t then there’s a sensor or other type of electrical issue causing it. In the meantime I would recommend leaving it at the house and driving the X1. I would not take my chances with that light, especially since neglecting it could cause even more damage.

 

[AK Wes]

Do you know if the fluid has ever been changed in your transmission? Have you noticed any spots where you park or fluid on your undercarriage that could indicate a small leak? I notice you have a 2000 LC so that means you have the trans dipstick. Can you wipe it on a paper towel and see what color it is and how it smells? It’d be great if you could get your hands on an OBDII reader like the ScanGauge II that allows you to monitor the temp in realtime. That would let you be able to see if the AT temp is abnormally high, or if it isn’t then there’s a sensor or other type of electrical issue causing it. In the meantime I would recommend leaving it at the house and driving the X1. I would not take my chances with that light, especially since neglecting it could cause even more damage.

Thanks for the reply!

I haven't changed the transmission fluid in the Land Cruiser, I have owned it for 6 years and have racked up just under 50k more miles on it. It has just shy of 190k miles on it currently. It's on my list to do a fluid swap coming up here in the near future. I didn't notice any issues with the fluid when I checked the dipstick a couple times yesterday and the fluid didn't seem abnormally warm either.

The story actually gets a little weirder..... The A/T Oil Temp light completely went away when I went to drive home in the evening yesterday and I have a pretty good 1,600' elevation gain for my drive home, so I expected it to appear again. I thought it was unrelated, but yesterday I was also getting a chime when the door was open, along with a buckle seat belt indicator light. I am thinking I may have some electrical issues surfacing that may have caused all these issues, including the A/T Oil Temp light. It has been raining extremely hard lately and once things dried out a bit all of these issues disappeared.

I decided to drive the cruiser again today and none of these issues happened again...... It also isn't pouring down rain today as it had been the last few days. While I'm not happy having electrical issues appear, I prefer this over transmission problems.

I'll post up any information if I can track down the problem.

 

[TheForger]

With that new info an electrical issue does sound more likely, which yes I agree is better than transmission problems to an extent. Water intrusion could be from a leaking windshield or clogged sunroof drains, most likely allowing water to travel down the drivers side A pillar and coming in contact with the fuse panel by the dead pedal. Are you experiencing any wet floor boards after it rains? Also, just above that fuse panel and to the left are a few spots where some wires are grounded from the factory. You could look and and see if any of those terminal’s are rusty/corroded. If so that’s a solid indicator that you do have a water leak from somewhere. I had that issue a few years back when money was tight and instead of paying to get the windshield fixed, I used 2 buckets of Damp-Rid (1 in each front floorboard) to help me keep mildew and a moldy smell from forming. Worked great in the meantime.

 

[flintknapper]

Agree that water intrusion or a poor ground somewhere is the likely issue. However, checking the A/T fluid temp should be a high priority for you, simply to avoid any damage being done there (or confirm impending Trans failure).

A ScanGauge or other monitoring system would be best....but sans that....you can use an IR gun and shoot the pan after a 30 minute drive.

It will pretty much reflect what the fluid temp is (in the pan) if taken immediately after driving. IF abnormal (anything above 160°F) then you should have it looked at. I would definitely do a drain and fill on it though.

 

[PhrogsPhorever]

4 speed or 5-speed box?

Had this problem on my '04 LX when I bought it.

If its not an electrical gremlin, check your tranny oil cooler lines, if they are crimped, bent or or boogered up at all, that will restrict the flow to the oil cooler and you will throw an A/T hot light. Mine was the line coming out of the radiator that apparently the stealership mashed during a service at some point. Had to replace the radiator

Scangauge is a good way to see if its an actual over-temp or just a faulty/shorted idiot light, there are multiple inputs you can custom program into the SG to get a good temp reading.

If you are just seeing this on the truck, then you should be good with no damage, but on the safe side I would have a sample tested to see what condition your fluid is in.

 

[flintknapper]

4 speed or 5-speed box?

Had this problem on my '04 LX when I bought it.

If its not an electrical gremlin, check your tranny oil cooler lines, if they are crimped, bent or or boogered up at all, that will restrict the flow to the oil cooler and you will throw an A/T hot light. Mine was the line coming out of the radiator that apparently the stealership mashed during a service at some point. Had to replace the radiator

Scangauge is a good way to see if its an actual over-temp or just a faulty/shorted idiot light, there are multiple inputs you can custom program into the SG to get a good temp reading.

If you are just seeing this on the truck, then you should be good with no damage, but on the safe side I would have a sample tested to see what condition your fluid is in.

Actually found a shipping plug in one of the lines of mine (blocking it). Tranny was getting hot.

 

[2001LC]

I like to start all inspections, by looking at all work done in history of vehicle. Getting to know the vehicle.

A/T temp light indicates something wrong with transmission. That something causes temp to raise is main reason for light, but not only. If ATF fluid good (level and condition), shifting good and A/T light only coming on while raining, which is cooler weather. I suspect short. In 98-03 it very easy to check level and condition. 04- up takes more effort, so first is to look for sign of leaks, this can save some time.

Additional of other dash lights and/or chimes and/or other systems failures only during wet conditions, are a further indication of water entry.

More than one issues seen when raining, after snow or car wash then they go away when dry. Are almost always windshield leaks. If windshield was replaced, that becomes number 1# suspect. I closely inspect molding around windshield. Looking for sign of windshield replacement and if a proper or poor install job. Sometimes it has been replaced poorly and then corrected later, so no current leak. So just because no current leak, water entry can't be ruled out. These are the faults that don't go away when dry.

1. Most common leak is rivet holes or new holes drilled for outside "A" molding are left open. Even rivet or screw (should not be used) not sung in hole can allow water entry.
2. Next is along top of windshield in center. There is a factory hole made for aligning a factory installed windshield. When aftermarket windshield installed this hole must be plugged. It often is not!
3. Rust under windshield, that has grown opening a gap or holes through to interior.

These aren't only leaks into cabin down "A" pillar or from around windshield, but most common. It is very important to stop these leaks. What happens is water creates a short. Understanding when these accrue and things like if parked outdoors and at what angle vehicle sit helps narrow search both for leak and short. Most common short seems to be in signal ground points. These points of signal ground have commonality of faults or warning lights and chimes of issue. Then it drys and all back to normal. But each cycle of drying back out, leaves behind corrosion or oxidation. Over time, this oxidation builds, until a point where fault is continuous.

I've diagnosed a few of these, this year and more over the years. I've seen in mud a few (100 and 200 series) totaled by insurance for windshield leaks. That have gone on long enough, water has build enough oxidation, fault does not go away when drying out. These get costly to diagnose and repair.

I did another this week. Windshield installing company owner brought me a large check himself to take care of issue. He has a string of good shop in Colorado and his guys are trained to do the difficult land Cruiser install. But he did not know about the one issue in center of windshield along roof line. Factory has a hole for factory windshields. Know he got and expensive lesson to teach his guys. I'll use him. But I'll still do all molding myself and go into shop during R&R of glass.

Sorry for going off so much on windshield or water entry, as it is only one possibility here.

 

[AK Wes]

I like to start all inspections, by looking at all work done in history of vehicle. Getting to know the vehicle.

A/T temp light indicates something wrong with transmission. That something causes temp to raise is main reason for light, but not only. If ATF fluid good (level and condition), shifting good and A/T light only coming on while raining, which is cooler weather. I suspect short. In 98-03 it very easy to check level and condition. 04- up takes more effort, so first is to look for sign of leaks, this can save some time.

Additional of other dash lights and/or chimes and/or other systems failures only during wet conditions, are a further indication of water entry.

More than one issues seen when raining, after snow or car wash then they go away when dry. Are almost always windshield leaks. If windshield was replaced, that becomes number 1# suspect. I closely inspect molding around windshield. Looking for sign of windshield replacement and if a proper or poor install job. Sometimes it has been replaced poorly and then corrected later, so no current leak. So just because no current leak, water entry can't be ruled out. These are the faults that don't go away when dry.

1. Most common leak is rivet holes or new holes drilled for outside "A" molding are left open. Even rivet or screw (should not be used) not sung in hole can allow water entry.
2. Next is along top of windshield in center. There is a factory hole made for aligning a factory installed windshield. When aftermarket windshield installed this hole must be plugged. It often is not!
3. Rust under windshield, that has grown opening a gap or holes through to interior.

These aren't only leaks into cabin down "A" pillar or from around windshield, but most common. It is very important to stop these leaks. What happens is water creates a short. Understanding when these accrue and things like if parked outdoors and at what angle vehicle sit helps narrow search both for leak and short. Most common short seems to be in signal ground points. These points of signal ground have commonality of faults or warning lights and chimes of issue. Then it drys and all back to normal. But each cycle of drying back out, leaves behind corrosion or oxidation. Over time, this oxidation builds, until a point where fault is continuous.

I've diagnosed a few of these, this year and more over the years. I've seen in mud a few (100 and 200 series) totaled by insurance for windshield leaks. That have gone on long enough, water has build enough oxidation, fault does not go away when drying out. These get costly to diagnose and repair.

I did another this week. Windshield installing company owner brought me a large check himself to take care of issue. He has a string of good shop in Colorado and his guys are trained to do the difficult land Cruiser install. But he did not know about the one issue in center of windshield along roof line. Factory has a hole for factory windshields. Know he got and expensive lesson to teach his guys. I'll use him. But I'll still do all molding myself and go into shop during R&R of glass.

Sorry for going off so much on windshield or water entry, as it is only one possibility here.

Thank you so much for the detailed reply. I had a busy weekend, so I wasn't on the forums at all....

I decided to drive my Cruiser for a couple more days last week, just so I could see if the issue continued and also to see if I could pinpoint the water intrusion locations. Sure enough, after sitting outside in some torrential downpouring rain I found water pooled up on my Weathertech floormat, near the driver side dead pedal. I could feel the water slowly dripping down onto my leg and foot while driving, so I brought it home and parked it in the garage over the weekend to dry out.

Living in Alaska it is VERY common to have a windshield replaced multiple times over the life of a vehicle and would say a typical lifespan of a windshield here is about 3 years. They don't salt the roads here, but they do put down gravel and sand, which obviously does some damage to the windshields. I had the windshield last replaced on this vehicle about 2 years ago, but it is still in great shape as I don't put too many miles on it anymore. I had Speedy Glass replace the windshield then and I am thinking they didn't do that great of a job. I called the local Speedy Glass shop and they said to bring it in for them to look over the windshield and see if they can view any issues with their installation. I'll be sure to review the three items you mentioned above when they are looking over my windshield. Do you have any photos of a completed windshield install, with trim removed, that I can use for reference?

Hoping the local shop can make this right and fix what was likely their mistake.

 

[flintknapper]

Hoping the local shop can make this right and fix what was likely their mistake.

Bet you anything at some point someone used screws instead of the proper rivets and left the old holes uncovered or didn't fill the hole at the pinchweld.

Had water damage in the form of rust under mine because of this (screws).

 

[2001LC]

I see three main water entry issues from windshield, I've online above. But don't rule at sun roof drain or bolt holes of roof rack, until all inspected.

Wind sound in cabin while driving HWY, is sometime associated with bad install leaving a hole open.

Pulling inside side molding and watch, as you run water from hose or sprinkler head selectively in location and with vehicle at different angles. Watch for water down "A" pillar. The vinyl tube is the sun roof drain. Pull both sides. You could very well be running down both sides, just not see on floor mats.
2001 no side air bag.

Pressurizing cabin then foaming with can of window cleaner or using very strong "bubbly" soap mix. Watch for bubble in area of leak can help isolate. I've seen installer use pressurize air from blow gun. But pressurizing cabin would work better to expose all windshield leaks. Some in mud say just close windows, turn on cabin fan to high, use fresh air mode. I've not tried and don't know if that would give enough pressure in cabin.

Just starting to leak now, after two years is not common. They usually leak as soon as bad install done. Rust caused by installer nicking paint, takes longer to create leak. This rust will often grow like a cancer and may crack the glass. These leaks are from rust holes into body.

Look here for pictures and write ups under: "Windshield" in index Buying, PM & Advance Maintenance of 100 & 200 series.

 

[BKLYNLandCruisn]

Im relatively new to this forum and experienced the same issue with my '99 Landcruiser this past weekend while traveling about 200 miles north of my home. A/T oil temp light came on during some heavy rain (also after a week of heavy rain in the city) and was unfortunately accompanied by the BRAKE light. both dimmed out within 30 sec and i have not seen them since.

My windshield was replaced by safelite in brooklyn at the beginning of this year (jan 2021). The tech installed a new windshield in some pretty cold weather and im pretty sure he struggled seal it properly. I battled terrible smells in the car all summer and could not find any moisture in the baseboards below floor mats - instead i blamed my friends for leaving beer cans in their golf bags which were spilling into the trunk area causing the mildew and smell. After a more recent heavy rain storm i checked all of the areas below the floormats and found the passenger side floorboard, below my weather tech mat was soaked. I am having a pressure test done in a couple days with my local safelite and i expecting the worst... given how long this leak has persisted - nearly 9 months.

I am not ruling out the possibility of a sunroof leak, but remain confident that this issue was caused by technician error while outside in cold weather.

If anyone has advice for me during my visit to the safelite shop, I welcome it. I will try to be as close to the inspection/diagnostics process as possible.

 

[2001LC]

Understanding how it should be installed correctly, is best advice I can give..

Look under windshield for links, in my master thread and search mud.

 

[BKLYNLandCruisn]

Thank you

 

[Heraldo]

Would the AT temp light cause the car to shut off?

 

[Mike NXP]

Would the AT temp light cause the car to shut off?

I don't think so.

 

[BnvS]

Yeah

Would the AT temp light cause the car to shut off?

It should'nt although driving on it for a bit may cause damage to the transmission...for obvious reasons.

 

[BullElk]

Would the AT temp light cause the car to shut off?

Are you having A/T temp light to come on and engine shut off at same time? Could be another issue I’ve seen before.

 

[Heraldo]

*Edit because I forgot to quote reply

 

[Heraldo]

Are you having A/T temp light to come on and engine shut off at same time? Could be another issue I’ve seen before.

Does anybody know which computer controls that sensor?
Because on my land cruiser it isn't sending temp data to my obdII scanner. And it is randomly shutting off the vehicle. All the while the temp of the transmission pan is 150. Verified my laser scan gun.
And the starter will sometimes stay on until I turn the vehicle off and back on again.