Scan Guage E or Ultra Guage II - Anyone using them currently?

Hey all,

Just seeing if there is any interest in people using scan-guages or UG for their P5's. If anyone is using one, which one do you use and the pros/cons of it would be greatly appreciated.

Ultra-guage - 70$
scan guage E - 100$

Thanks ahead of time!

I just got my Ultra-Gauge and I am pleased with it so far but like the other post, I too find that my car is always in open loop.

http://www.mazdas247.com/forum/showthread.php?123809881-ultragauge-shows-my-p5-stuck-in-open-loop

I guess it's just our ecu but I would like to know if it really ever is in closed loop or not. I'll keep an eye on the O2, mass air flow and injector cut off gauges to see what I can find out. I don't know how the Ultra-Gauge compares to the Scan Gauge but they both plug into the OBD-ll port under the dash so I guess they are not as good as a wideband. I don't know, but I believe the wideband has to be hard wired into each sensor so my gauge appears more convenient.

Does Scan Gauge E read our car to be in closed loop?? Or any gauge for that matter??

This is a quote from a year ago:

The following was quoted from the Ultra-Gauge Support Help Desk:

We have not heard from any other Mazda owners on this issue. Actually, the only open loop issues to date are related to the Diesel vehicles only.
Are there any Trouble codes or Pending trouble codes present?

If the system is truly open loop the fuel mixture will be off and your mileage may suffer. In addition, UG relies on the vehicle being in closed loop in order to provide accurate fuel usage calculations. Fortunately the Mazda Protege uses a Mass Air Flow (MAF) sensor, so when in closed loop, results should be very accurate.

If there are no codes, then it is likely that for what ever reason, the vehicles computer is falsely returning the loop status. In which case, you should ignore the loop indicator.

Open loop is the state of the emission system and is solely determined by the ECU. The ECU must see several conditions prior to declaring that the system can go closed loop. Primary to that is the O2 sensor(s).

End Quote.

i love my scangauge...it's super handy. it does have some annoying things though. 1) sometimes it resets when i shift into reverse 2) it USUALLY resets when you turn the car off. sometimes if you start it again fast enough, it will continue with the mileage you had. i'm not sure if this can be changed. i havent looked into it yet

Does it show closed and open loop ??

The UG has settings for engine on and engine off.

i think so.. I'll check when i go to work and update when i get home tonight

Great Thanks.

below 40MPH it ALWAYS said Closed loop...above 40 it said closed when i was on the gas and open when i was coasting. as soon as i touched the throttle it would go back to closed


edit: i also realized it was open loop for about 30 seconds after start up

Posted this in another thread, figured it is relevant here as well.

Did a little driving with the Torque app today. Sadly I forgot to plug everything in after the car had been sitting overnight. So I haven't tested it on a true cold start. During one start the temperature gauge started at it's lowest point, but the car had only been sitting for about an hour and a half. However, during all of this it always said it was in closed loop. With the only exception being that when you decelerate with no throttle it switches to open loop. I took some screen shots on my phone to show what it is saying.

<iframe src="https://skydrive.live.com/embed?cid=5AA886B2BC80B78C&resid=5AA886B2BC80B78C%21236&authkey=AGED7s_f7GEaxV8" width="180" height="320" frameborder="0" scrolling="no"></iframe> <iframe src="https://skydrive.live.com/embed?cid=5AA886B2BC80B78C&resid=5AA886B2BC80B78C%21237&authkey=ANer3qzjQfQi9JA" width="180" height="320" frameborder="0" scrolling="no"></iframe>

I was wondering about that 255 MPG reading. I'm assuming that that is the Instantaneous MPG reading during deceleration for our cars. There was a guy on a different forum (one for 4x4 trucks) that was using a gauge (I forget which one) and he was wondering why the Instantaneous MPG went up to 999.9 MPG when he was coasting in gear. I believe that is because the vehicle cuts the fuel completely until the clutch or neutral switch is engaged activating idle speed fuel flow. I believe our cars do this too (O2 sensors Volts drop to 0.000 during deceleration) which means we are travelling using no gas so the gauge should top out at 999.9 MPG ???!!

As far as I know pretty much all modern cars do not use fuel while coasting. As far as it saying 255, it is probably just the way it is programed. Technically it should say 999.9, but then again where do you stop? If you are not limited by character places, it should read 9999999.9 MPG since we are talking about infinite MPG. I'm not sure how it effects the overall average MPG calculation. I'm sure each of the devices have their own way of compensating. Lets say you had a 3 mile long hill that you could coast down using no gas. I know some on board computers go to 99.9, the scan-gauge (presumably) goes to 999.9, and then we have the hypothetical 99999999.9. It would be interesting to see the average MPG from each of those if the entire trip was only, say, 3.5 miles long. Would all three devices end up having the same average, even though their coasting numbers are significantly different?

Luken10 said:

As far as I know pretty much all modern cars do not use fuel while coasting. As far as it saying 255, it is probably just the way it is programed. Technically it should say 999.9, but then again where do you stop? If you are not limited by character places, it should read 9999999.9 MPG since we are talking about infinite MPG. I'm not sure how it effects the overall average MPG calculation. I'm sure each of the devices have their own way of compensating. Lets say you had a 3 mile long hill that you could coast down using no gas. I know some on board computers go to 99.9, the scan-gauge (presumably) goes to 999.9, and then we have the hypothetical 99999999.9. It would be interesting to see the average MPG from each of those if the entire trip was only, say, 3.5 miles long. Would all three devices end up having the same average, even though their coasting numbers are significantly different?

Click to expand...

Yea,.. I get what you mean,.. It appears that the UG Isn't reading maximum value (regardless of the decimal place. I do get a small O2 reading while coasting when it is warming up but then it goes to zero suggesting no fuel when warm and a little bit until then) on other vehicles it will read Max (999.9). My question is why not our cars.
I'm trying to send an informed e-mail to UG asking for help on this issue.

I wonder how much of a difference all of this (and other anomalies) makes and how to interpret the values given. (When coasting, the fuel trim is reading 0 as well. I think it should be reading maximum negative value (regardless of the decimal point))
This gauge is having a hard time talking to our cars,... I'd like to know about all of the communication issues then fire off an e-mail to UG to see if they can direct me on some sort of resolution.

I still think this unit is priceless even if just for the engine coolant temp, and Volt meter alone (the UG Volt meter was just added (it reads the input voltage to the unit (our cars ECU do not support a volt meter but the newest version does give a reading.)) I'm guessing the V meter might be in real time because it reads from the input voltage not the ECU (0.9 second refresh rate) so you could use it to monitor maximum voltage drop with your booming car stereo to decide whether or not to upgrade your Alt and wiring.

I would like to get 200 MPG some day even if I have to coast down a mountain side using the trip meter to do it.

i coasted down a mountain once and reset my scangauge at the top. i started off with 2000+MPG (yes 3 zeros) and it slowly worked its way down to the 200-300 range by the time I got to the bottom