Transmission light on. Out in the bush

Mark_BC

Mark_BC

Senior Member
I took the restored 2000 out to saltspring island yesterday. No issues. I was driving at speed. This morning I did a little exploring down some slow winding gravel roads with hills and the transmission light came on. I presume its because there wasnt enough airflow across the inline transmission cooler I put in. The b&n one. So now I'm just sitting out here for half an hour waiting for it to cool down. Hopefully I didn't cook it. The fluid looks and smells ok on the dipstick. Level is low, I guess because the cooler volume took up some fluid. I'm not leaking any.
 
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I've been here half an hour and the light is still on. Could it be because the level is low? I can top it up as soon as I get back in town, 5-10 Kim away.
 
You need to have the engine idling to have the transmission pump circulating the hot fluid through the cooler. These overheating risks are enough reason alone of why bypassing is not ideal. Not to mention operating temp delays.
 
Yes I saw that in my manual too. I've been sitting here for over an hour and idling for maybe 15 minutes. Topped up the fluid and the light is still on. Surely by now it would have cooled down? I'll check for a code.
 
Pulling codes 0441 and 0446 which are evap issues makes sense since I just replaced the box. I have an obd2 reader, does anyone know how I can make it read transmission temp? I searched before and was a bit overwhelmed and my connection out here is bad.
 
Yes, you can configure an XGauge in the scangauge to read transmission temps on your truck

Here are the codes I used for mine:
TXD: 686AF101B4
RXF: 044105B40000
RXD: 2808
MTH: 00090005FFD8
NAME: TFT
Notes: n/a, displays in degrees F

Good luck!
 
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I got the scangauge programmed and its reading 105, just went down to 104 after idling for a minute. Light still on so there must be some other problem.
 
rightyouareken said:
Yes, you can configure an XGauge in the scangauge to read transmission temps on your truck

Here are the codes I used for mine:
TXD: 686AF101B4
RXF: 044105B40000
RXD: 2808
MTH: 00090005FFD8
NAME: TFT
Notes: n/a, displays in degrees F

Good luck!
Click to expand...

Hey do you know if this work on earlier years? I can't get the AT temp on my OBD2 reader from my 99.
 
Mark_BC said:
I got the scangauge programmed and its reading 105, just went down to 104 after idling for a minute. Light still on so there must be some other problem.
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I don't know if it would help but maybe if you disconnect the battery for a bit that might clear the light? Just a total guess sorry, don't have experience with transmission lights on these.
 
rightyouareken said:
I don't know if it would help but maybe if you disconnect the battery for a bit that might clear the light? Just a total guess sorry, don't have experience with transmission lights on these.
Click to expand...

Right you are, [MENTION=326755]rightyouareken[/MENTION]. It worked. So I probably briefly overheated it. Since them the maximum I've been able to get it is 190 going up a big hill. I'll look into acceptable temps more.
 
Mark_BC said:
Right you are, [MENTION=326755]rightyouareken[/MENTION]. It worked. So I probably briefly overheated it. Since them the maximum I've been able to get it is 190 going up a big hill. I'll look into acceptable temps more.
Click to expand...

Glad to hear man! Keep an eye on those temps. If you get much above 220-230 I'd stop and idle it for a bit to let it cool back down. Normal temps are in the 150-180F range in around town driving. 200-220 is not unusual when climbing, but try not to run it in that range long. Over 240 is starting to get a bit scary.

Locking out overdrive on hills over 45mph can keep temps down, and using 4lo off-road at low speed can reduce stress on it too.
 
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I re-drove a lot of my route after setting the scangauge up and I would be very surprised if I even approached 200 the first time. Strange. Maybe because it was low on fluid, on one of the short hills it was sucking air briefly?
 
IIRC it’s something like 240 or more? Basically if the light comes on, regular AT fluid is cooked by then. It’s really not a “warning” light, but rather a “danger” light.
 
Mark_BC said:
Does anyone know at what temp the light turns on?
Click to expand...

The light comes on at around 300 degrees. Your fluid is cooked and you should do a full flush. When you were wheeling, were you doing any sustained climbs? I learned that using 4Lo can make a huge difference with your trans temps if you're climbing any sustained grades. The downside to using 4Lo is you're tacking out at around 20-25 mph but it really makes a difference with your trans temp. You should really start monitoring your trans temp. As you have found out the hard way, it's important. You can either use a scan gauge or use a Bluetooth OBD II reader that sends info to a phone app like Torque Pro. If you have an Android phone, you can use Torque Pro.

Check out this video. In the video description, I provide helpful links.

<iframe width="560" height="315" src="https://www.youtube.com/embed/wqxeZvljYGc" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
I wheeled for about 5-10 minutes, climbing maybe a couple hundred feet over a couple kilometers over varied ups and downs, averaging about 20 mph. I had it in hi 1st. There's no way I reached 300. Not even 200. I felt the cooler at the time and it was warm but not hot. The fluid looks fine. The only thing I can think of is that because the fluid was low, it sent an erroneous reading during one of the ups or downs due to the slope. Outside temperature was around 60. Edit: if the fluid is cooked will it be obvious?
 
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