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I am getting my new scangauge (xgauge and fuel-cutoff included) pretty well setup.
After getting the speed calibrated, things started to improve.
I calibrate against my toyota's own fuel consumption display (integrated in the stereo...)

The throtte-position is always at 10 when doing NICE-on coasting, so I tried to set the fuel cutoff to 10. Didn't work at all. The scangauge would never show cutoff.

Then I tried 11, and it seems to follow my car's display very closely. A slight tendency to show more cutoff than my car, but that might be caused more or less by the car having a larger running average/delay on the update. The scangauge seems to update by instant samples rather than doing any averaging.

The default value of 24 caused the scangauge to show fuelcut way too often.

Currently increased the cutoff value to 12 to see what the implications are.

I too have been setting up my new scangauge, including the fuet cut-off. However, I did not see anything refering to this set-up parameter in the manual. I sent Linear-logic and e-mail regarding this feature and how to go about setting it up.

Shrek- How did you find the fuel dut-off was controlled throttle position? Just by comparing to the iFCD on your car?

I'm using my scangauge in a 2006 civic coupe 5A, and it seems that the default setting of 24 correctly shows the cut-off when I'm in coasting in gear. Mt throttle position when in neutral is 17, but my LOD is 24.

Is it possible the fuel cut-off is dependent on LOD as opposed to TPS?

My guess was 10x gph reading. My car does not have fuel cut and I had to set it to a value very low in order to avoid triggering that feature because at the end of a pulse in my manual transmission car (getting off the gas and throwing the shifter into neutral) I can get a very low dip in consumption as it approaches idle speed.

Check your gph readout when coasting and when idling -- I'd be interested in hearing if coasting is below 2.4gph and idling is above.

The last time I checked when my car is stopped but in drive my GPH reads 0.24 with a LOD of 28-30. If I shift into Neutral GPH=0.16-0.18 and LOD=~25.

During a DICE-on coast with the tach above 1000rpm (most of the time), the MPG=9999, GPH=0.00, and LOD=23-8 with the higher RPM pushing LOD to the lower end. Compared to NICE-on coasting where to GPH=0.21, LOD=~25, and MPG is determined by speed. I think the LOD has something to do with how the scangauge determines fuel cut-off, but I'm not sure how it works into the equation.

I too have been setting up my new scangauge, including the fuet cut-off. However, I did not see anything refering to this set-up parameter in the manual. I sent Linear-logic and e-mail regarding this feature and how to go about setting it up.

Shrek- How did you find the fuel dut-off was controlled throttle position? Just by comparing to the iFCD on your car?

I'm using my scangauge in a 2006 civic coupe 5A, and it seems that the default setting of 24 correctly shows the cut-off when I'm in coasting in gear. Mt throttle position when in neutral is 17, but my LOD is 24.

Is it possible the fuel cut-off is dependent on LOD as opposed to TPS?


I have checked, and the fuelcut is very coincident with open-loop mode.

I have seen a forum a while ago discussing this, and referring to throttle-position.
It makes sense, as open-loop operation will occur at high-power also, and you want to avoid SG thinking that is a fuel-cut situation.

I'll check the correspondence with LOD also as soon as possible.

I heard back from Ron at Linear-Logic and here is his response about the CUTOFF value in the settings.

"The CUTOFF was a last minute addition to the ScanGaugeII. Some vehicles will report when they shut off fuel flow during coasting with the engine in gear. The same signal also indicates when the vehicle is enriching the fuel mixture during hard acceleration. If the throttle position is below the CUTOFF value when this signal is received, the ScanGaugeII assumes it means 0 fuel flow. Above this it means enriched flow. Normally you should not have to change this. If your TPS is above this level when you are coasting with your foot off the accelerator, you would need to raise it. If you set it to 0, this detection is turned off.

We are working on the Honda codes now. Can you tell us if the 06 Civic is CANSF or ISO? From the home screen, use MORE>MORE>MODE to see this on the top line.

Ron"

So the CUTOFF function is dependent on the TPS value. However, Ron does mention that this should only be changed if your TPS reads higher that 24 during an in gear coast. I supposed the opposite could be true where if your TPS is below 24 during an in gear coast you can change the CUTOFF value to a number closer to what your TPS reads as long as it's above the TPS value while coasting in gear.

I'm confused. TPS is the Throttle Position Sensor -- is that actually the throttle valve opening and not the pedal position?

TPS is throttle position sensor - not accelerator pedal position.

It's a subtle, but important distinction. On most cars, they are nearly linearly related.
But on DBW cars, the ECU controls the throttle and the pedal is just an input to the ECU.

There's something in the back of my mind about some early implementations of OBD II and TPS sensor readings. I'll have to look it up. Vague recollection is that a few folks report the same value for closed throttle and WOT.

-mr. bill

Hm. I thought it was reading the pedal position. I'll have to do some experiments to see if TPS dips where I was getting what the SG thought was fuel cut when I let off the pedal right after a pulse and dropped the transmission into neutral.

PS: Nice to hear from you again, Bill! :)

after a pulse and you drop into neutral you won't get the fuel cut. the fuel cut-off only works when you are in gear. this is because the engine is using the car's momentum to turn the engine over through the transmission. If you put the transmission into neutral there is no connection to the engine and the engine would have to idle using fuel. The TPS does read the actual throttle valve, and haven't seen it drop to 0 while coasting in gear.

The best place to use the fuel cut feature is when coeasting to a stop or coasting down a hill to maintain speed.

Thanks -- I'm aware of its uses but my car does not have this feature. I mentioned the after pulse behavior because what I saw was an odd fluctuation in instantaneous consistent with the ScanGauge thinking I was in fuel cut. I adjusted the feature to never activate and it went away.

What I saw was a kick to 9999mpg right after finishing the pulse and dropping to neutral. This was at peak RPM. The instantaneous would then drop to something reasonable as the tachometer needle descended... until it got close to idle. At that point it would again kick to 9999mpg briefly before returning to what it should show at idle for the speed. With the feature turned off, I see the numbers blip up a bit at those points, but not all the way to 9999mpg.

Coasting down in gear nets me only a few more mpg over steady state cruising because I lack fuel cut.

Disagree that fuel cut only works while in gear!

After a pulse to say 3000 RPM, totally remove foot from accelerator pedal, push in the clutch or put it in neutral you *WILL* get a brief fuel cutoff until RPM drops to ~1000 RPM. Your engine is using the momentum of the flywheel to keep turning.

In a manual transmission car, you save a wee bit of fuel with each upshift because of this!

-mr. bill

True that the flywheel will keep the engine turning over for a short period of time that could give you the criteria needed for the fuel cutoff. However, the gains from such a short period are fairly minimal, but not to be over looked. The most fuel efficient method of using the fuel cut-off is to coast down in the highest gear possible for your speed.

Disagree that fuel cut only works while in gear!

After a pulse to say 3000 RPM, totally remove foot from accelerator pedal, push in the clutch or put it in neutral you *WILL* get a brief fuel cutoff until RPM drops to ~1000 RPM. Your engine is using the momentum of the flywheel to keep turning.

In a manual transmission car, you save a wee bit of fuel with each upshift because of this!

-mr. bill

Interesting. I do see this behaviour on the SG, but not on the iFCD of the car. I think the iFCD has a filter to avoid showing this behaviour (probably so as to not worry the not-so-technical drivers and have them running to the dealer with questions)

Does the Fuel Cutoff in the SGII effect its MPG calcs? I know that even in cutoff, my ICE uses a minimal amount of fuel.

Well, I'm upgrading my SGII to the new firmware next week, but trust me, without fuel cutoff detection, you can get fairly high wrong GPH values at >7,000 RPM no throttle.

-mr. bill

OK, I'm still trying to wrap my mind around this fuel cutoff idea. Since I've started hypermiling I've just been trying to be in neutral as often as possible because I thought that was the best way to save fuel. I was willing to sacrifice the additional wear on my brakes. This complicates things. So....

In a MT car with fuel cutoff, if you're gliding in gear and cutoff is activated, you aren't using fuel and the engine is still spinning and still powering the power steering/brakes etc. right? So then if you push in the clutch at this point without touching the gas, disconnecting the engine from the transmission and wheels, you're saying the engine automatically restarts so it can idle and provide power while you're in neutral? I would think you would notice that happening.

Looks like I might have to hook the SG back up and do some experimenting. Is fuel cutoff more prevalent in certain makes, models, or since a certain year?

you're saying the engine automatically restarts so it can idle and provide power while you're in neutral? I would think you would notice that happening.

...Is fuel cutoff more prevalent in certain makes, models, or since a certain year?

You can definitely tell when fuel cutoff ends in my car when it's at fast idle. If you're coasting down in gear to an intersection in gear at fast idle (when the PCM only allows 2d gear max anyway), the car will slow down until it's below the fast idle speed. At that point, it jerks slightly and maintains the idle RPM closed-loop, which also maintains a certain minimum speed.

AFAIK Fuel cutoff doesn't exist in carbureted cars, so it wouldn't have existed at all before the mid-1980s, when fuel injection started becoming more common. My car's engine was in production in 1998, although the previous generation may have had it as well.

Looks like I might have to hook the SG back up and do some experimenting. Is fuel cutoff more prevalent in certain makes, models, or since a certain year?

Toyota has been using it for many years now. I'll guess since 1986-1990 (?)

Thanks. My car does act like it has it.

How can you find out if your vehicle has 'fuel cut'? I called 2 local Mazda dealerships and spoke to their service manager & technician. When I asked them if my '98 626 4cyl Auto had 'fuel cut' all responded with "What is 'fuel cut'? I explained to them my understanding... that when the car is in Drive and coasting (downhill or to a stop sign) fuel would not be fed to the cylinders and the engine would continue to run because the car is moving & it is engaged with the transmission.

All stated, "No Mazda has been built with this type of engine management, only Hybrids".

Sounds like either I don't understand 'Fuel Cut' or I need to speak to someone more knowledgeable. Do I understand 'Fuel Cut' correctly? How can I find out if my car has it?

A side question: How do I get my posts to show my vehicle year, make& model, so I don't have to write it in each time? I've added it to my profile & garage but still doesn't show.

Thanks everyone!

Hi, Laker! You've got the idea just fine. Another name for this feature is DFCO (Deceleration Fuel Cut Off) -- you can also ask if the fuel injectors are shut off during engine braking above 1100 RPM.

For the information in the banner of your posts, go back to your user preferences (click the User CP link in the second to top horizontal blue bar -- all the way to the left) and then click the Edit Profile link (third from the top of the Control Panel column). Answer the questions at the very bottom and those will go in the banner for you. :)

How can you find out if your vehicle has 'fuel cut'?

You should be able to tell if you have it by how it cuts back in. You could try the following:

- warmed up engine
- driving at 50 mph
- shift down to 3rd if it is a 4 speed auto
- lift off the gas and coast

It should decelerate fairly quickly. Once the RPMs get down between 1500 rpm and 1000 rpm see if you feel something like a sudden release almost as if the brakes had been on every so slightly and then let go. That feeling of going from slightly stopping to smoothly gliding, almost as if it slipped into neutral, will let you know that your car is equipped with DFCO.

Sean - Now I know what the acronym 'DFCO' means. I've seen it and past it over many times. Appreciate the further explanation & what to ask the "Professionals". :rolleyes:

2TJB - Thanks for the test steps. I'll check it out now as I head for home! ;)

By the way if haven't heard this from others, the willingness to help, amount of tested & knowledge of what works and tone with which members voice their opinions is truly impressive! :woot: Oh and I'm always laughing at the lighthearted comments! You people seem to enjoy life and it shows. :bananalama: Keep it up and pass the compliment along.
Cheers,

Stephen

My 2000 Honda CRV Auto Trans seems to have fuel cut on decel with a bit of delay per scanguage.

My 2003 Toyota Tacoma V6 Auto Trans has never reported 9999s for iMPG, so I think it is always burning my fuel.

I think I will never purchase another car without DFCO.

It would be great if we could tabulate at least the common fuel economy cars according to which years, trannys, etc have DFCO and other nice FE features. Auto trannys that can be FAS'd comes to mind, like at least some Accords.

OK, I'm still trying to wrap my mind around this fuel cutoff idea. Since I've started hypermiling I've just been trying to be in neutral as often as possible because I thought that was the best way to save fuel. I was willing to sacrifice the additional wear on my brakes. This complicates things. So....

In a MT car with fuel cutoff, if you're gliding in gear and cutoff is activated, you aren't using fuel and the engine is still spinning and still powering the power steering/brakes etc. right? So then if you push in the clutch at this point without touching the gas, disconnecting the engine from the transmission and wheels, you're saying the engine automatically restarts so it can idle and provide power while you're in neutral? I would think you would notice that happening.

Looks like I might have to hook the SG back up and do some experimenting. Is fuel cutoff more prevalent in certain makes, models, or since a certain year?

Hi!

Toyota's (at least european - with which I am familiar) seem to have had this for many years. More than 10-15 years at least.

I usually do a lot of coasting in neutral, but when I try to hunt the cutoff I can improve the mileage quite a bit. Some long hills have the correct descent so that in cutoff you will just loose some speed but otherwise you will not feel much difference from neutral coast.

It is easier with a manual. Just put it into 5'th gear and see what happens. If you are too slow it will not cutoff, and you might have to pulse a bit to get more speed. When you get to a sweet spot with the rpm just above idle you can coast with cutoff in very shallow descents and not loose speed.

Here's another way to tell if you're getting DFCO:

Use the SG and watch the LOOP gauge. It should be in Closed Loop (system is watching the O2 sensor and adjusting as needed) most of the time. But, it should show Open Loop in DFCO - no fuel, so no need to monitor the exhaust mixture.

DFCO may be old-hat on Toyotas, but it's a very new feature on other makes. My recently divested '96 Subaru Outback did NOT have it, nor does my coworker's '98 Mazda Protege. My 2000 VW Golf TDI and 2001 VW Jetta (gas) both DO have it.

Thanks for the explanation that DFCO also engages when the engine is revving down to idle speed. That explains why my SGII always shows 0.0GPH for a split second, then back to 0.18GPH, when I take the car out of gear or upshift.

Yep. Stick Toyo's do the same thing on shifting. It's because you let the throttle off to nothing long enough.My 2003 Toyota Tacoma V6 Auto Trans has never reported 9999s for iMPG, so I think it is always burning my fuel.Come off the gas before an off ramp or going down hill (or intentionally downshift- but, don't make that a practice). Make sure your SGII cutoff is set correctly.

Pretty sure your Tacoma has it. Its just that auto trans don't do DFCO as often as sticks do. I've noticed the same thing w/my Avy. It doesn't stay in DFCO for that long..... and it stops DFCO when you reach a certain RPM threshold. It was kind of wild the 1st time I watched it.... when DFCO kicked off at the RPM threshold..... the RPMs bumped back up.

GM had it back in 88 and perhaps before?

My 2000 Honda CRV Auto Trans seems to have fuel cut on decel with a bit of delay per scanguage.




I think there is a technical challenge for the automakers to avoid the fuel-cut kicking in too suddenly while driving on slippery ice/snow. the sudden fuelcut could give enough increase in engine brake power to make the wheels start slipping. Imagine the lawsuits!

Because of this I believe that the fuelcut is gradual, and possibly even (easy enough to program) coupled with the ABS sensors.

There is already enough of a problem with 4x4's sliding out of the road because drivers let go of the gas pedal while cornering on icy roads here in Norway.

Make sure your SGII cutoff is set correctly.

Pretty sure your Tacoma has it. Its just that auto trans don't do DFCO as often as sticks do. I've noticed the same thing w/my Avy. It doesn't stay in DFCO for that long..... and it stops DFCO when you reach a certain RPM threshold. It was kind of wild the 1st time I watched it.... when DFCO kicked off at the RPM threshold..... the RPMs bumped back up.

I've never seen the 2003 AT Tacoma go open loop after brief warmup (closed loop at around 62F). I never go WOT, so I assume it would go open loop there. Anyway, I've tried cutoff at default 24 and at 15 (idle tps is 14ish). I should have raised the default, I guess, but if it never goes open loop it won't show DFCO.

What makes you think the Tacoma has DFCO?

I've never seen the 2003 AT Tacoma go open loop after brief warmup (closed loop at around 62F). I never go WOT, so I assume it would go open loop there. Anyway, I've tried cutoff at default 24 and at 15 (idle tps is 14ish). I should have raised the default, I guess, but if it never goes open loop it won't show DFCO.

What makes you think the Tacoma has DFCO?15 should be fine.

It being a late model EFI Toyota makes me think it has DFCO. Its probably the automatic tranny. Like I said... about the only time I see the Avy go DFCO is when I come off the accelerator @ highway speed and let it coast to an offramp or I come off on a good size down hill. I checked the Celica Service Manual... and it too comes out of DFCO @ 1.5KRPMS.

I'm checking your Service Manual now.... http://www.ncttora.com/fsm/2003/2003_FSM.zip if you don't have a copy;) Your fuel return is @ 1.2K RPMs for a 2003 A/T Tacoma. And yes, you do have DFCO:D

Thanks, 2Way!

I had the FSM, but lack familiarity with it. Haven't had it on highway since SGII was upgraded.

No problem :)

BTW:
My 2000 Honda CRV Auto Trans seems to have fuel cut on decel with a bit of delay per scanguage.there is a comm delay from the SG <-> ECM... so, some of the delay is actually from that.

I can confirm now that the 2003 Tacoma AT has DFCO. It is triggered at highway speeds on the off ramps, and I can induce it by downshifting approaching stops/turns at lower speed (but I'm usually in N).

Overall, it is less inclined to go into DFCO than our 2000 CRV and FAR less inclined than our new 2008 Honda Fit with the 5AT.

Thanks again to 2way for leading me on the Taco.

Just to update some of my experiences...

The scanguage has been recognizing fuel cut-off most of the time. I say this because about a week ago it started to not recognize the cut, and my MPG numbers were noticeably lower compared to the previous week (no driving style changes).

I set the scangauge to defaults and entered in my old calibration values afterwards and everything worked ok. Not quite sure what was going on with it, but I'll see if it happens again.

2way is correct. Most automatic trans won't do Dfco that much do to the fact that an auto, when coasting in gear, is actually not directly linked to the engine and using the engine to slow the vehicle. The torque converter will unlock and most, not all, of the engine braking never actually gets utilized. For that reason, the ECU must continue to burn fuel in the ICE to keep it running since most of the vehicles kinetic energy is not being scrubed off by the vehicle's drivetrain (a good thing for glide situations). A manual trans doesn't have that problem since there is a direct link to the wheels through the clutch. So, the weight of the vehicle, and its kinetic energy, during the coast in gear time can be used to keep the engine turning over even though there is no fuel being shot by the injectors.

I know Ford had Dfco in the late 80s because I have a 5.0 Mustang that I can adjust all of the ECU functions, one of which is the fuel cutoff point - basically, the RPM at which the fuel cutoff stops working. I had it adjusted way down to something like 1,000 RPM, but the motor didn't like it too much. I think the default was somewhere around 1,500 RPM and it worked in any forward gear. The car is a 5-speed manual.

I've just had a new issue occur with my scangauge II today. While driving to work the gauge suddenly read 9999MPG and 0.00GPH while I was accelerating (although slowly and on flat ground). I'm not sure what would cause it to do this, but I'm pretty sure if the computer was saying no fuel was being injected the car would have stalled out.

I re-set to the defaults again and everything seems to work ok. The only trending I can think of is this usually occurs right after I'm at a light in which I had the ICE off. Maybe the scangauge has issues after repeated on/off cycles?

Thoughts?

P.S.- I e-mail linear-logic with my questions as well.

I've just had a new issue occur with my scangauge II today. While driving to work the gauge suddenly read 9999MPG and 0.00GPH while I was accelerating (although slowly and on flat ground). I'm not sure what would cause it to do this, but I'm pretty sure if the computer was saying no fuel was being injected the car would have stalled out.

I re-set to the defaults again and everything seems to work ok. The only trending I can think of is this usually occurs right after I'm at a light in which I had the ICE off. Maybe the scangauge has issues after repeated on/off cycles?

Thoughts?

P.S.- I e-mail linear-logic with my questions as well.

Your car goes open-loop at full throttle. The scangauge need to know what is your idle throttle position (there is a menu called fuel-cut for that) so that it knows that it should not indicate fuel-cut in this situation.

The default value is quite high, and on some cars this can happen. Find the TPS at idle, then add 1 and set that as the value in the fuel-cut menu.

The default value is quite high, and on some cars this can happen. Find the TPS at idle, then add 1 and set that as the value in the fuel-cut menu.Werd

Looked at my idle TPS and it read 14 when fully warmed. I set it at 16 because it'll idle at 15 on cold starts. We'll see if this helps any...

Even though you weren't @ full throttle, if you had just restarted the car you may have been in Open Loop. With the default setting (24 I think) fairly high, it becomes more of an Open Loop indicator than a fuel cut indicator. That's why you want to set the Fuel Cut level just above the idle TPS reading. You don't want it sensing the Open Loop mode when you are above idle TPS.

It's seems as though my tps is ALWAYS 0 if my foot is not on the gas, which I'm assuming means closed throttle. The scangauge manual says that some cars do this so I'm guessing mine is one of them. So, how am I supposed to set the fuelcut? I'm pretty sure my car has it because I looked up my engine in a GM diagnostic chart and it refers to Dfco.

If idle TPS is 0... then set the Fuel Cutoff to 1.

It appears that the Nissan Tiida/Versa (w/CVT) is programmed to maintain torque converter lock-up down to about 18km/h. So DFCO is maintained down to really low speeds. The exception to this is when the A/C compressor is running. This is actually nice because it allows you to decelerate toward a mis-timed/unavoidable stop light or to go to N for a nice long coast. Too bad the oil pump is driven by the input shaft and doesn't support FAS.

The other interesting thing is the CVT appears to prefer doing its own rev-match and re-engaging at speed (i.e. it doesn't like you to tap the accelerator pedal when shifting from N to D at speed). Problem is it takes a great deal of control on the accelerator pedal to nudge the transmission back into lock-up quickly after that.

The Tiida/Versa doesn't appear to be popular here in this forum. I always wonder to myself about the numbers Wayne would be able to pull off on my car type and route... Now if Wayne ever comes to Singapore I would really like to have him show me the ropes.

2way is correct. Most automatic trans won't do Dfco that much do to the fact that an auto, when coasting in gear, is actually not directly linked to the engine and using the engine to slow the vehicle. The torque converter will unlock and most, not all, of the engine braking never actually gets utilized. For that reason, the ECU must continue to burn fuel in the ICE to keep it running since most of the vehicles kinetic energy is not being scrubed off by the vehicle's drivetrain (a good thing for glide situations). A manual trans doesn't have that problem since there is a direct link to the wheels through the clutch. So, the weight of the vehicle, and its kinetic energy, during the coast in gear time can be used to keep the engine turning over even though there is no fuel being shot by the injectors.

I myself dont understand how to adjust the cutoff setting..
need me some n00b help for sure :)

my manual doesnt even mention it AT ALL..

my tps at idol goes as low as 10

I believe the convention around here is to add "1" to your idle TPS to arrive at the correct cutoff setting. For your car that would put it at "11." I can't tell you from experience because the Elantra doesn't have DFCO and though the Insight does I've not bothered putting the SG into it because it doesn't read lean burn mode correctly.

I myself dont understand how to adjust the cutoff setting..
need me some n00b help for sure :)

my manual doesnt even mention it AT ALL..

my tps at idol goes as low as 10

With a manual you'll learn to love the cut-off in no time.

Do a series of coasts in various gears all down to idle, and learn
to feel the response.

I love it when I time a dfco coast so that I seamlessly transfer clutchlessly into a nice-on coast or idle-driven-low-speed-mode(*) just as the dfco shut off - for example to follow a slowly moving queue.


(*)Letting the engine move the car at idle in 2-3-4'th gear at an rpm below the usual idle rpm with an instant FE that can be even lower than the trip average.

With a manual you'll learn to love the cut-off in no time.

Do a series of coasts in various gears all down to idle, and learn
to feel the response.

I love it when I time a dfco coast so that I seamlessly transfer clutchlessly into a nice-on coast or idle-driven-low-speed-mode(*) just as the dfco shut off - for example to follow a slowly moving queue.


(*)Letting the engine move the car at idle in 2-3-4'th gear at an rpm below the usual idle rpm with an instant FE that can be even lower than the trip average.

my main problem is that I dont understand what the cutoff is for or how to detect the responce..

what kind of responce are we talking about?

The cutoff is to indicate to the ScanGauge that you are in DFCO and the injectors are shut off. When this happens and cutoff is set correctly, the ScanGauge will read 9999 on the iFCD and GPH goes to 0.

I have a 2004 Nissan Frontier and I know from the service manual that it states there is a fuel cutoff on decelleration. That said the TPS is 0 at idle. What happens if I simply de-activate the Fuel Cut-off feature? I do not want inaccurate readings. Any suggestions with regards to my truck? BTW it's an auto. Thanks in advance.

Set the cutoff to 1. I'm not sure on what it does for accuracy.... but, it helps if you want to take advantage of DFCO.

I have a 2004 Nissan Frontier and I know from the service manual that it states there is a fuel cutoff on decelleration. That said the TPS is 0 at idle. What happens if I simply de-activate the Fuel Cut-off feature? I do not want inaccurate readings. Any suggestions with regards to my truck? BTW it's an auto. Thanks in advance.
Idle TPS reading shouldn't be a problem since it will be closed loop except when initially warming up. Look at TPS and LP when coasting down in gear to get an idea of what value to choose. A setting of 1 will almost certainly never invoke fuel cut.

The cutoff is to indicate to the ScanGauge that you are in DFCO and the injectors are shut off. When this happens and cutoff is set correctly, the ScanGauge will read 9999 on the iFCD and GPH goes to 0.

I'll check the GPH to see what it sais when downshifting.. never thought of that DUH!

forgive me, I'm 1/2 n00bish on my fathers side :Banane13:

A BIG Thank you to Wyane .. I got my scan gauge 2 about an hour & a half a go........
I am like a little kid at Christmas!~!!!!!!!1
Next time Wyane I'll pay the extra to go NON-usps!!!!!
Got it !!!!!Wyane & am real happy!!!!!!! 18th to the 29th.... maybe the
scan gauge had to go tru customs comeing into New Mexico (grin)
Thanks AGAIN

Idle TPS reading shouldn't be a problem since it will be closed loop except when initially warming up. Look at TPS and LP when coasting down in gear to get an idea of what value to choose. A setting of 1 will almost certainly never invoke fuel cut.Yes & no. If TPS is 0 at idle and indicates closed throttle, a setting of 1 should work just fine. As you say, the idea is that you want to know throttle closed & Open Loop. When set to 1, if you go below, it indicates a closed throttle (TPS=0). In one of my cases, idle TPS is 10 and my cutoff=11.