Ultragauge funnies

Just got my Ultragauge MX 1.3 hooked up to my 05 DC and am seeing some funny readings. Thought I would pass along to others for comment.
The first thing I did was the trans flush and fill. All went well until I tried to use the UG to monitor the trans temp. Outside temp was 65 deg, but the trans would not get above 111 deg after 20 minutes of idling in P. Finally got it to go to 117 by going to R with the E-brake on. Then did the overflow to drain off excess.
Next I took the camper out for a 30 mile tow, monitoring trans temp, instant mpg, and torque converter lock (1=locked). Starting from a stop and watching TC status: 1st gear, TC=1; 2nd, TC=0; 3rd, TC=1; 4th, TC=0; 5th, TC=1. Now here is the strange part. Leaving the truck in D, when going up a hill, the trans downshifts (TC=0) and rpms & temp go up. Shifting to 4, rpms go up again, temp the same, and TC=0. Downshifting to 3, rpms go up again and TC=1. I always thought 4 is the recommended gear for towing, but it looks like with TC=0 there is no TC lock up there. The trans temp varied wildly, going from 150 on level road in D, to 185 on long uphills in 4. The best mileage was in D on level road at 55, even slightly uphill. Thought that lugging the engine would be worse for mpg than downshifting, but that was not the case. Lowest trans temp was in D on level road. Other gears, temp was higher.
One last strange one; coasting downhill in N, trans temp goes up fast!
Guess I'll be towing in D, but will downshift if trans starts hunting excessively.
Interested in comments from others who use UG & tow.

 

No where in the owners manual does it say to tow in 4. My 2008 Tundra 4.7 was the same way.

 

Leaving the truck in D, when going up a hill, the trans downshifts (TC=0) and rpms & temp go up.

Don't think it downshifted, just TC unlocked.

 

So I'm not going to pretend to be a transmission expert, but I do frequently find firmware bugs for a living. This sequence that you report while accelerating (I presume?):

That makes no sense to me. When accelerating you should never see TC=1. And while I have no knowledge of what the Tacoma does for sure in general having TC=1 in 1st gear is a strange thing no matter what.

What it really looks like to me is the UG is not reporting the TC properly. It almost looks like the TC is just the least significant bit of the gear as you are getting TC=1 for all the odd gears and never for the even gears.

I can't exactly determine what happened when you say this:

Do you mean that the transmission downshifted to 4th gear and at that point TC=0?

The key question here is: Are you always seeing TC=1 if the gear is odd and always seeing TC=0 if the gear is even? Is this true regardless of whether accelerating or at constant speed? If the answers to those questions are "yes" then I think you are just seeing a bug in the UG and don't actually know what the TC is really doing.

 

So far the UG is the worst purchase for my truck. They have great marketing but the actual usability of the product is minimal. I think that the company should post what actual gauges work with each model specific vehicle. UG says they have 97 available gauges. When I booted up I had 57 per my truck. Just because a speicif gauge can be read in both US and Metric DOES NOT convert into 2 different gauges! You have to reset the DTE gauge at each fill-up. Average mileage is so far off from reality I sure wouldn't trust it if my fuel gauge went out!!! Still trying to figure out the real use for this thing. Maybe if you have a decked out you get to use more if the less than useful gauges. All the numbers change and it looks real pretty but less than useful as a tool for better driving!

 

I took mine off the glass. Went through emissions and never put it back up. The only useful gauges I saw were the coolant and voltages.

 

I've seen similar results with mine.

Not sure if the trans lock up is delayed a bit.

 

The torque converter will ONLY lock up in fourth or fifth gear.

Moving the shifer to 4 instead of D simply locks out the trans from shifting to 5th... That's it. It does not change how the trans shifts or what gears it locks up in. What will change how it shifts is the load the trans is seeing... If it feels more weight it will hang onto gears longer etc.

The only reason to put her in 4th is if your hunting for gears between 4th or 5th or spending an excessive time in 5th unlocked... Putting it in 4th will force it to go into lockup easier which will keep trans temps at bay.

If you take a little bit of time to feel for your truck you know exactly when its locked up in either of those gears simply by feel and rpms

 

If we know that for sure then it lends a lot of weight to my theory the OP's UG is lying to him and there is a software bug passing the LSB of the gear value to him as the TC lock bit.

 

i know it for a fact that this is the case as its stated in the factory service manual.... just see for yourself.... throw your truck in 3rd and cruise down the road at 32+mph (torque converter does not lock in ANY gear below 32mph) You will notice that in 3rd crusing at say 45, if you roll into the throttle rpms will rise a decent amount but the truck speed does not rise the same amount. This is due to the "slipping" nature of a torque converter that is not locked up.

 

Ah, excellent. What you describe is exactly how I'd expect the TC lock to behave on almost any vehicle - only on the upper most gears and only above a certain speed. I just didn't have enough experience with the Tacoma to know if it was the same.

So I'm going to strengthen my claim that the issue here is the the UG is simply not reporting the TC lock properly. The OP's UG is reporting something the FSM says is not possible and it is pretty easy to understand a bug in processing the OBD information giving the erroneous results the OP is seeing from his UG.

Thanks for following up on my question!

 

It's definitely not reporting properly - there is no way the convertor is locked in 1st gear sitting at a stop sign in mine ...
Sarge

 

if it was... the engine would of stalled.

 

It's a cute little gauge and looks good up just under my mirror but, in reality it's pretty useless.

 

yeah honestly never been really impressed with scan gauges / ultra guage..... i have more information thats WAY more customization at my fingertips via an old android phone and torque pro.... all for free.

 

You know what is kind of odd? I just looked at Torque Pro and thought "this isn't all that great either." Then I thought "what am I really looking for in the way of information?" Hmmm, maybe good, old fashion gauge information. Oil pressure, water temp, amp draw, maybe tire pressures. What I think I have found is that the computer in my truck and probably many others isn't savy enough to know what the fuel level is which is one of the main reasons I bought the Ultragauge. I shouldn't have to reset the gauge every time I fill up and then it guesses at the information given. Like I said, it really does look cool with all the numbers changing all the time. I set mine up with MPH, RPM (both of those to verify the truck gauges, Ave MPG, intake air temp (because the ambient temp is included), barometric pressure. I couldn't see any other gauges that were even remotely interesting or useful. Just my opinion

 

I have torque pro telling me trans pan temps and torque converter output temps, i only really use it when towing to keep an eye on those temps. But from what i have seen, the stock tow package trans cooler does a pretty good job at keeping temps under control.

 

Torque Pro FTW!

 

Oh, it isn't rocket science on how to use it. With a 4cyl, and a 5spd there isn't much to tell. It would be nice to get water temp but that isn't available, neither is ambient air temp, oil pressure, engine oil and transmission oil temp (for towing), all not available. So, it isn't about knowing or not knowing how to use it. It's about the available gauges on their website and the actual gauges that work on a specific vehicle. Somewhere close to a worthless POS

 

I would be concerned about those Trans temps... they seem a little high to keep the trans safe.

If you're going to tow often, add a trans cooler.