Range AFM Delete and Emissions

[wsteele]

I realized I had hijacked a thread on Tahoe/Yukon longevity with a complete side track of how the Range device affects emissions testing readiness when it is pulled out before you go in for an emissions test, so I thought I would move things over here (if anyone really cares. ).

There have been a few posts on how pulling the Range device out of the ODBII port affects the emissions readiness status. Some have been able to pull it just before testing and pass no problem, others mention they need to drive around for like a week with it out, before going in for the test.

In my personal experience, this is what I have noticed with my 2007 Yukon, 5.3L (LMG) Flex Fuel engine and my Range dongle.

Here are the results on my $20 ODBII scanner, after pulling my Range AFM Delete device out, like I would before going in fo my test.




I tried warming the car up to see if the Not Passed would clear and they remained. I have located a generic GM Trip criteria and will try it when I get some time and can drive it for 15 minutes or so to perform the standard GM Trip and report back what happens.

My goal is to figure how exactly how little I need to drive it in AFM mode to clear all the flags, before I take it in for emissions tests. My concern is with the AFM deleted with the Range device, I worry that oil sludge has a chance to build up in the oil manifold and may impact AFM performance during the time I am driving the car around clearing the emissions readiness flags. I frankly think this concern may be unfounded, given all the reports by other members of this forum of successful use of the Range device for a very long time. But being a belt and suspenders kind of person, I want to do all I can to eliminate this concern.

I figured out how to upload screen shots pretty easily now, so as soon as I have the trip completed, I will post the results.

 

[Geotrash]

My concern is with the AFM deleted with the Range device, I worry that oil sludge has a chance to build up in the oil manifold and may impact AFM performance during the time I am driving the car around clearing the emissions readiness flags. I frankly think this concern may be unfounded, given all the reports by other members of this forum of successful use of the Range device for a very long time. But being a belt and suspenders kind of person, I want to do all I can to eliminate this concern.

Let's go back to this part. In my opinion, this is not worth worrying about if you're keeping up with oil changes and your oil pressure is normal. I removed my Range device after more than a year and then unplugged it to get the black bear tune data I needed. No problem at all. Also, that little filter screen below the oil pressure sender is there to trap any debris that would otherwise find its way into the VLOM solenoids, so as long as your engine still has that, the risk is even lower. Keep in mind that your lifters will also only see filtered oil from the engine's oil filter anyway.

 

[Sparksalot]

I realized I had hijacked a thread on Tahoe/Yukon longevity with a complete side track of how the Range device affects emissions testing readiness when it is pulled out before you go in for an emissions test, so I thought I would move things over here (if anyone really cares. ).

There have been a few posts on how pulling the Range device out of the ODBII port affects the emissions readiness status. Some have been able to pull it just before testing and pass no problem, others mention they need to drive around for like a week with it out, before going in for the test.

In my personal experience, this is what I have noticed with my 2007 Yukon, 5.3L (LMG) Flex Fuel engine and my Range dongle.

Here are the results on my $20 ODBII scanner, after pulling my Range AFM Delete device out, like I would before going in fo my test.

View attachment 268839
View attachment 268841

I tried warming the car up to see if the Not Passed would clear and they remained. I have located a generic GM Trip criteria and will try it when I get some time and can drive it for 15 minutes or so to perform the standard GM Trip and report back what happens.

My goal is to figure how exactly how little I need to drive it in AFM mode to clear all the flags, before I take it in for emissions tests. My concern is with the AFM deleted with the Range device, I worry that oil sludge has a chance to build up in the oil manifold and may impact AFM performance during the time I am driving the car around clearing the emissions readiness flags. I frankly think this concern may be unfounded, given all the reports by other members of this forum of successful use of the Range device for a very long time. But being a belt and suspenders kind of person, I want to do all I can to eliminate this concern.

I figured out how to upload screen shots pretty easily now, so as soon as I have the trip completed, I will post the results.

What do each of the two test results represent?

 

[wsteele]

What do each of the two test results represent?

Just two pages of one readiness scan. It says I have 4 items that need a trip criteria met, I think.

 

[89Suburban]

Bill a big THANKS for taking the time to research this and ease both our pains!!!

I know I reported you I take mine out a week prior to the test, that was to be safe. My mechanic says it needs to be driven at least 50 miles and a certain number of start cycles but I forget that part. I am pretty sure just a few days of driving should cover that normally, for me anyway. Can't wait to see your results.

 

[wsteele]

Bill a big THANKS for taking the time to research this and ease both our pains!!!

I know I reported you I take mine out a week prior to the test, that was to be safe. My mechanic says it needs to be driven at least 50 miles and a certain number of start cycles but I forget that part. I am pretty sure just a few days of driving should cover that normally, for me anyway. Can't wait to see your results.

I think your results are right down the middle of the fairway of most people's experience. I found the following on a few different sites. I will say, I have read some posts by a few other, extremely credible guys, whose experience with the Range seemed to indicate, at least in their state, a drive cycle wasn't required. All of this being anecdotal, I think all I might actually accomplish is just a little higher confidence of what may work in MY circumstance.

General Motors Driving Cycle
A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.

To perform an OBDII Driving cycle do the following:

1. Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.
   
2. Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.
   
3. Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
   
4. Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
   
5. Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
   
6. Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.
   
7. Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.
   
8. Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.

I have also found a "Universal trip" version of the above. Based on its name, I suspect it should work on any ODBII car. I will post it when I can.

I am going to test the GM version as closely as I can to its prescription and see if all the flags that are present just after I remove the Range dongle from my ODBII port, are reset.

I have seen advice on other procedures which include start, idle for 30 sec, a drive for at least 5 minutes at 25 mph, 30 secs of idle before shutting the key off, etc. I will try each of these I find, that also seem to be from a credible source, and report any results.

Ultimately, like @Sparksalot posted, my concerns of an annual or bi-annual drive to clear readiness flags that appear to be set by the removal of the Range dongle are probably a stretch at a minimum. Looking at the pictures of your engine after so many miles, my fears of sludge buildup in the VLOM affecting the probability of a lifter failure seem pretty far fetched. In any case, knowing exactly what I have to do to clear those flags before I go to get my emissions test, seems like the least I can do.

 

[Sparksalot]

I am curious why just turning off the AFM would cause any issues at all. The system doesn’t change any emissions, just economy.

 

[wsteele]

I am curious why just turning off the AFM would cause any issues at all. The system doesn’t change any emissions, just economy.

I would also like to know that, although I suspect we only are going to get some, hopefully, credible speculation on that. Short of having the source code of the software controlling these functions, all I have gotten so far is the above observation and the reports of many that they have to drive their car to clear the flags before they go in for an emissions test.

Ultimately, I would like to know "exactly" what I have to do when I pull the Range device before an emissions test, regardless of any fears I have of exacerbating AFM lifter woes on my car.

As an aside, I had the regional manager for Fraser (reman engines) reach out as a result of some inquiries I made of his firm regarding buying a reman engine, sans AFM. I like to have my options known before bad things happen. He stated they do offer an AFM deleted version and recommend it. Nice to know at least one company is thinking outside the box.

 

[iamdub]

I am curious why just turning off the AFM would cause any issues at all. The system doesn’t change any emissions, just economy.

It's not that it changes the emissions. It's passing the emissions part of a vehicle inspection. If a vehicle has a problem with its emission system and there's a code stored, it'll fail emissions and not pass inspection. To keep someone from simply clearing the codes then running to the inspection station before the light has a chance to come back on, there are monitors in place that check various systems before they're granted "ready" status (ready for inspection). These systems have to operate within satisfactory parameters for a number of drive cycles. A drive cycle may consist of one or more of events such as a minimum number of miles, an amount of time, through a number of gear changes, through an amount of idle time, etc. Some systems don't need very many drive cycles or need to meet very may parameters at all before they've satisfied the monitors while others need to "jump through a lot of hoops" with 100% success.

Apparently, using and/or unplugging the Range resets these readiness monitors. It's something with how the Range disables AFM. My guess is that it keeps certain systems from ever passing their readiness cycles and that's what keeps AFM from activating. Then, when it's unplugged, those systems eventually pass the monitors (if there are no problems) and then the vehicle is ready to be tested for inspection.

I wonder if someone could plug a Y-adapter to the OBD port and have the Range on one leg and a scan tool on the other to see if and what systems drop out of readiness mode.

 

[wsteele]

It's not that it changes the emissions. It's passing the emissions part of a vehicle inspection. If a vehicle has a problem with its emission system and there's a code stored, it'll fail emissions and not pass inspection. To keep someone from simply clearing the codes then running to the inspection station before the light has a chance to come back on, there are monitors in place that check various systems before they're granted "ready" status (ready for inspection). These systems have to operate within satisfactory parameters for a number of drive cycles. A drive cycle may consist of one or more of events such as a minimum number of miles, an amount of time, through a number of gear changes, through an amount of idle time, etc. Some systems don't need very many drive cycles or need to meet very may parameters at all before they've satisfied the monitors while others need to "jump through a lot of hoops" with 100% success.

Apparently, using and/or unplugging the Range resets these readiness monitors. It's something with how the Range disables AFM. My guess is that it keeps certain systems from ever passing their readiness cycles and that's what keeps AFM from activating. Then, when it's unplugged, those systems eventually pass the monitors (if there are no problems) and then the vehicle is ready to be tested for inspection.

I wonder if someone could plug a Y-adapter to the OBD port and have the Range on one leg and a scan tool on the other to see if and what systems drop out of readiness mode.

The Y connector is a great idea.