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Discussion Starter · #1 ·
I'm not one for "idiot lights" that tell you that you have a problem "after" the problem has occurred. I know there is a dashboard light that come on when the coolant temp is too high. I'm used to a gauge so I can see when things start to get hot. Am I just missing the gauge in my quick trip around the dashboard?

Thanks!
JeffnDallas
 

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unfortunately there's no gauge for that. the prius is pretty lacking in gauges.

DH has only seen one prius overheat, and that was because it was damaged in an accident and the system was improperly refilled. the prius coolant system is tricky to do it RIGHT.

if you want detailed info, head over to PriusChat.com and do a quick search for the CAN-VIEW monitor. that has a LOT of info on it.
 

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OK Phil, I should have these printed up!. The Prius is the only car I have found made with NO, ZERO, NADA guages of any kind and relies upon idiot lights entirely. Doesn't seem to bother most purchasers however who only seem to need a speedo and Gas guage. However do not let a little thing like this deter you if you really want to own the best hybrid made today for the buck.

Although there is no aftermarket for guages of any kind and none are adaptable account all power info comes from computers, it is possible to purchase an instrument called a "scan guage" which simply plugs into the OB2 socket under your dashboard and is made to mount at several places on your dashboard. The guage gives you four pieces of information that you can select from a dozen offered. I have mine indicating at all times, engine rpm, coolant temperature, 12 volt ammeter, and car speed. Unfortunately oil pressure is unattainable. I haven't even been able to determine in the service manuals where the source of this comes from and you just have to rely on the idiot light. (Scan guage costs $130.00, and is well worth it just to determine when your engine (ICE) is running which is not continuously indicated with the info on the Multi Function Display.)
 

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Discussion Starter · #5 ·
Hi Hyperion. Thanks for the reply...I thought it was just me who was mystified by the lack of guages. You're right...it made no difference in my decision to buy the hybrid. I'm so confident in the quality of Toyota that I'm guessing the idiot lights probably will never come on.

But....I would like to look into that device you mentioned...do you have a link? Also...I was just on the coastaletech.com website yesterday and I believe I saw a device they were selling that has a light on it to tell you when the ICE is running/not running. I only mention this because you said that's the one function you couldn't find.

Thanks again!

JeffnDallas
 

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Jeff, that engine run light that Coastal Tech sells is for the first generation Prius and is not adaptable to the 04's and newer. He does list one he developed for the later cars but as yet has not put it in production.

Try http://www.scanguage.com for complete info on the scan guage sold by a company in Phoenix.

If you purchase one, it has to be programed for the hybrid and a lot of folks don't go quite far enough with the directions which ask for engine displacement (1.5 L) and type of fuel. You have to skip through diesel and gas to get to "hybrid"
 

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Discussion Starter · #7 ·
Thanks much! I'll take a look.

I also looked at the CAN-VIEW thread on Prius Chat. I used to be an electrical engineer and that was like going to school again :D

Hey everyone....have a great New Year!!

Jeff
 

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DanMan32 said:
attila said:
http://www.vassfamily.net/ToyotaPrius/CAN/cindex.html#OC

Happy New Year!
Did you ever get that to work with CanUSB?
Not yet, but honestly, I haven't tried yet... Just too darn busy at work and home... I hope to give it an other this month though... :roll:
 

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Prius Gages, or lack of

Yes, I love my ScanGage because even with all of the computerized safeguards it is still possible to:

1. Run Down the 12V Battery.
.
.
.
Duh, I guess there is much else that Can go wrong with the Prius safegaurds.

However, the Prius is so complex and has so many sensors, that the instrument panel will look like a Jet Aircraft or Space Shuttle to get all those niffty readings!

Want a taste for just the TEMPERATURE Sensors?
1. Fuel Tank Temperature
2. Air Intake Temperature
3. Coolant Tank Outlet Temperature
4. Engine Coolant Tank Temperature
5. HV Battery Module Temperature (3)
6. HV Battery Air Temperature
7. MG1 Inverter Temp
8. MG2 Inverter Temp
9. MG2 Temp
10. Transaxle Fluid Temp
11. Boost Converter Temp
12. AC Room Temp
13. Evaporator Temp
14. Outside Air Temp
15. MG1 Temp

Guess, I will have to trust in the Prius Control systems.
 

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Let's be honest about cars and dash gauges. First off, the data you are presented in a dash gauge on a conventional vehicle is heavily sanitized before it gets to you. With regard to engine temp, most manufacturers present this data in an analog format and on top of that there is a NORMAL range shown on the dial and that is about as much as you know about the engine temp on the vehicle. Some vehicles have a digital info center which you can cycle through engine information, including actual coolant temp, but that is only on luxury cars, etc.

But the point is that the analog gauge shows you a relative temp reading, but nothing particularly accurate. All the cars I have driven previous to the Prius have had gauge packages and honestly they didn't ever tell me that much. If a car is going to overheat it is going to peg the needle and that is about it. Likewise if the Prius is going to overheat it will hit the light and shutdown the vehicle (which is a plus in many respects). I can't think of too many situations in which the Prius would be a candidate for repeated overheating. In hot summer weather the Prius is less likely to overheat because it isn't going to run its engine at stoplights, which is where most cars tend to stray toward overheating and it will continue to cycle coolant even while the ICE is off.

So, I do not miss the gauges. Especially knowing that other safeguards and processes are in place.
 

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jeromep said:
... and it will continue to cycle coolant even while the ICE is off.
Unless it is trying to provide cabin heat, which is unlikely during the summer as you mentioned, why would it do that? Coolant is moved electrically only when being transferred to/from the storage tank, or to provide cabin heat. Otherwise, if no additional heat is being generated, there's no reason to get rid of it with an electric pump.

I have found temp guages quite useful in the past, though I agree it wouldn't be as useful in the Prius, except maybe to determine what warmup stage it is in.
I have detected stuck open thermostats on 2 cars I owned, and was able to control an overheat with my Saturn before it got bad. Was a bad cooling fan motor.
 

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Guages are for people who have some understanding of what is going on under the hood of the car. It doesn't matter one iota how they are calibrated. If you ever pay that much attention to the guages in any car you will observe that under all normal operation the needles all point to dead center. It's as good as a red light dawning on an aware driver. You don't care if the needle is pointing to 100 degrees or 300 as long as you realize that if it is pointing to the right of center something is not right. Same with an ammeter and oil presure guage.
I use to have people come up in a 747 cockpit and ask "how the heck do you keep track of what is going on with the several hundred guages to watch and the answer is, you don't, but just let one get out of it's normal position and it stands out better than a red light.
I usually find that the person that does not miss the guages would not miss his rear view mirror. They are the drivers that would overlook the marked increase in the coolant temperature guage until a hose blows on the radiator. You see them often times at the side of the road with the hood up and the steam pouring out. I dare say that they would observe a red warning light and continue on until the hose blows wondering what the heck that red light means.
 

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I have heard stories of Dodge owners in the 70's frying engines, because the overtemp light on their old Desoto used to BLINK when it was VERY hot, and the Dodge lights don't blink.

In fact, one hot summer day on the 101 near Santa Maria (CA), a Dart-ful of old ladies came steaming in where I was parked and as they came to a stop the engine siezed. When asked, she said, "Yes, I saw the light, but I thought it would blink if it was serious."

By the way, she had a temp gauge on her dash...
 

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Discussion Starter · #17 ·
I recently had a vehicle where the gasket around the radiator cap got worn and the radiator would not hold pressure. As a result, when the engine got hot, coolant expanded into the pastic tank...but as the engine cooled, the coolant was not sucked back into the radiator. I was able to tell something was wrong because when I got off the highway, the temperature guage slowly started to rise, but at higher speeds it cooled. I knew something was wrong....but didn't know what! I was able to drive 300 miles back home keeping an eye on the gauge and controlling my speed to be sure that it didn't get too hot.

So....YES....I really do think it would be nice to have a temp gauge :lol:

Jeff
 

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hyperion said:
Guages are for people who have some understanding of what is going on under the hood of the car. It doesn't matter one iota how they are calibrated. If you ever pay that much attention to the guages in any car you will observe that under all normal operation the needles all point to dead center.
Not true. I have a 20 year old Topaz and and during the summer when cruising the temp needle is between the O and the R of a pretty typical mid-80s Ford C-NORMAL-H temp gauge. In the winter it is lucky to get past the N and the O of that same gauge. And at a long stop light in the summer the gauge will easily creap up to the M and A area of the gauge. There is definitly temperature changes happening, but the amount and degree of those changes remain a mystery to me.

The Tempo/Topaz series of cars was for many, and remains for me, a love-hate relationship. It is probably one of the most mechanically tough cars out there, with probably one of the weakest front end designes of any vehicle out there. Tie-rods are a major problem, good for only about 80k and allignments are difficult to keep on the car. On top of that, it has one of the most unplesant engine compartments I have ever had the displeasure of working in and I'm convinced that it is also one of the hottest engine compartments out there because it doesn't appear to have good air flow through the engine compartment for component cooling; and hot air from the exhaust manafold gets trapped between the engine and the fire wall with noplace to escape and little or no visible airflow.

My point is that a gauge can be useful, however the Topaz wouldn't kill itself if it were overheating to protect itself. It would just keep going and going. Modern vehicles today, with or without a gauge, will do that and probably more, such as cylinder alternating fireing so you can drive to safety.
hyperion said:
It's as good as a red light dawning on an aware driver. You don't care if the needle is pointing to 100 degrees or 300 as long as you realize that if it is pointing to the right of center something is not right. Same with an ammeter and oil presure guage.
I use to have people come up in a 747 cockpit and ask "how the heck do you keep track of what is going on with the several hundred guages to watch and the answer is, you don't, but just let one get out of it's normal position and it stands out better than a red light.
That makes complete sense. I can see that especially being the case if you have a series of guages measuring the same thing on, say, 4 engines which should all have the same readings assuming that the engines are running at the same RPM under the same shared load etc.

So, the Topaz temp gauge tells me stuff, but I wouldn't call it accurate, only moderately informative. However, on that vehicle I know that I'm responsible for making sure that I take precautions if the vehicle starts to overheat. On the other hand on the Prius, I know that its systems will shut it down in an overheat condition. I'm inclined to believe that the overheat light will occure at about the same time the vehicle says no go and turns it all off.
hyperion said:
I usually find that the person that does not miss the guages would not miss his rear view mirror. They are the drivers that would overlook the marked increase in the coolant temperature guage until a hose blows on the radiator. You see them often times at the side of the road with the hood up and the steam pouring out. I dare say that they would observe a red warning light and continue on until the hose blows wondering what the heck that red light means.
Isn't that kind of a broad brush stroke to paint others with, hypeion?
 

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Obviously I don't jeromep. However not much surprises me anymore since I purchased my Prius. It looks to me that 99% of Prius buyers don't care one iota about what instruments are for or do and yet spend a good portion of the time wondering about what they are seeing on the MFD which is more of a toy and conversation piece than any indication of the workings of the car.
When the only guage on the car (a fuel guage) can't be figured out for what it is I'm not surprised about the lack of interest for any other info being desired.
If anyone cares to run a scan guage constantly they would observe that the cars "workings" are not even closely indicated on the MFD.
The car is run by computers we have no control over and it does it's job just fine. As long as it stays on the ground, that's O.K. If it fails, you coast to the side of the road, call and have it fixed. They didn't put 2 ECM's or 2 BCM's into the car as a backup because we have breakdown lanes.
We have forams like this to keep the info flowing and I think it is great although when I see something posted I have never seen before on this board (cruise control runaway) and the subject is locked out because it might have been run to death on another board I am surely disappointed with the complete lack of more info on why it was locked out??
The date on the posted article was Jan 9 and as far as I could determine it had not been posted by "fish antlers."
Did a 05 Prius "run away" or not?
 

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Hyp, I think the "runaway" thread was posted twice, and only one was locked. (not 100% sure, I get PC and POL mixed sometimes).

http://www.priusonline.com/viewtopic.php?t=7162

http://priuschat.com/index.php?s=8d36f8 ... opic=14707

http://priuschat.com/A-wild-ride-in-a-Prius-t14596.html


Personally, I'd like gauges. Better would be a "virtual gauge" set in an easily-accessed MFD screen. I am the type to examine and explore and understand. I'd very much prefer to have this information easily available as a diagnistic and early warning.

One problem is that their behavior would baffle most drivers. For a car that can basically (once started) be driven just like any other [except for it's terrifyingly confusing horn button location ;-) ], I do a lot of explaining. "What does this button do?" "How do I turn it off?" "Why won't it go into D now?" Gauges that behave in unexpected ways would generate dozens more. "Why did the temp just drop?" "What does THIS mean?"

On the other hand, others wouldn't want to borrow my "overly complicated" car anymore. Hmmm, maybe we're onto something...
 
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