2017 Silverado with Range AFM Disabler Backfiring

[Huntere]

So I have recently purchased a Range AFM disabler for my 2017 Silverado 1500 E-assist because of the constant stopping and starting at stop lights, exhaust drone from V4, weird shifting from V4 to V8 and my transmission liking to jerk/shifting hard every so often.

 

After installing the Range device, it has solved my transmission issues, disabled stopping and starting at stop lights, and has been keeping it in V8 mode 24/7! The only thing I have noticed is that when I am decelerating from a speed of around 50 MPH or more, the engine will have a fast repetitive backfiring popping sound until i either get back on the gas pedal or have reached a speed of 35 MPH.

 

It seems to happen when i am decelerating slowly and not fast, starts to backfire when it starts to downshift at around 900-1100 RPMs

I have a flowmaster Super40 cat-back dual 2.5 inch exhaust with the third "cat" still on. It used to not backfire when the AFM was active BUT when decelerating, it would switch back into V4 mode. is there a way to fix this? Is there too much freeflowing exhaust? Can this backfiring through the exhaust cause any damage if left unfixed?

 

Thanks,

-Hunter

Edited May 15, 2019 by Huntere

[JimCost2014]

1 hour ago, Huntere said:

So I have recently purchased a Range AFM disabler for my 2017 Silverado 1500 E-assist because of the constant stopping and starting at stop lights, exhaust drone from V4, weird shifting from V4 to V8 and my transmission liking to jerk/shifting hard every so often.

 

After installing the Range device, it has solved my transmission issues, disabled stopping and starting at stop lights, and has been keeping it in V8 mode 24/7! The only thing I have noticed is that when I am decelerating from a speed of around 50 MPH or more, the engine will have a fast repetitive backfiring popping sound until i either get back on the gas pedal or have reached a speed of 35 MPH.

 

It seems to happen when i am decelerating slowly and not fast, starts to backfire when it starts to downshift at around 900-1100 RPMs

I have a flowmaster Super40 cat-back dual 2.5 inch exhaust with the third "cat" still on. It used to not backfire when the AFM was active BUT when decelerating, it would switch back into V4 mode. is there a way to fix this? Is there too much freeflowing exhaust? Can this backfiring through the exhaust cause any damage if left unfixed?

 

Thanks,

-Hunter

Is your CEL on yet?

Do you have a way to see if codes have been set off? Might have an auto parts store hook up a scanner just to be safe.

 

Would imagine the back firing will destroy your cats pretty quick.

[Huntere]

Just now, JimCost2014 said:

Is your CEL on yet?

Do you have a way to see if codes have been set off? Might have an auto parts store hook up a scanner just to be safe.

 

Would imagine the back firing will destroy your cats pretty quick.

So far no CEL yet, I have a friend who has a scanner that might work. I wonder what could be causing that backfiring?

[JimCost2014]

Have you taken the Range out and driven it?

 

I had one in my 14 and it set off the CEL every time I used it, you might also have the wrong version for your truck.

[Huntere]

3 minutes ago, JimCost2014 said:

Have you taken the Range out and driven it?

 

I had one in my 14 and it set off the CEL every time I used it, you might also have the wrong version for your truck.

I have about 30 minutes ago and it did not backfire when switching from V4 back to V8 like it used to , and no backfiring while decelerating. It goes into V4 mode while decelerating, maybe that is why?

I recently purchased the Range device directly from them, they said it has the most up to date firmware too.

Edited May 15, 2019 by Huntere

[JimCost2014]

2 minutes ago, Huntere said:

I have about 30 minutes ago and it did not backfire when switching from V4 back to V8 like it used to , and no backfiring while decelerating. It goes into V4 mode while decelerating, maybe that is why?

I recently purchased the Range device directly from them, they said it has the most up to date firmware too.

These trucks do not seem to like to have things plugged into the OBDII port for some reason.

 

I would drive it for a few days with the Range and see if it happens again, if not it was probably the Range device.

 

Going into V4 mode will not make it backfire. Just cause a drone effect on the exhaust note.

[Huntere]

4 minutes ago, JimCost2014 said:

These trucks do not seem to like to have things plugged into the OBDII port for some reason.

 

I would drive it for a few days with the Range and see if it happens again, if not it was probably the Range device.

 

Going into V4 mode will not make it backfire. Just cause a drone effect on the exhaust note.

Thank you, I'll see what happens over the next couple of days.

Hopefully whatever is causing it to backfire is not a constant thing, because this Range device has solved all of the major problems I have been having on this truck and I would hate for it to be causing a problem that might damage another thing and have to get rid of it.

Edited May 15, 2019 by Huntere

[3tspapat]

Drive it in L mode with 7th gear selected. This will disable start/stop and also AFM. If you still have the same issues, then it's not the Range, but rather the set up that you have. 

eAssists loves to stay in V4 mode.

 

I currently have 2018 eAssist and with the range noticed some hard shifting. Sent it back to Range for firmware update. But even now noticing shifting has gotten harder. Think it's just time to take it in for the TSB.

[JimCost2014]

3 hours ago, Huntere said:

Thank you, I'll see what happens over the next couple of days.

Hopefully whatever is causing it to backfire is not a constant thing, because this Range device has solved all of the major problems I have been having on this truck and I would hate for it to be causing a problem that might damage another thing and have to get rid of it.

You are very welcome,

 

And sorry, meant to say drive without Range to see how truck acts.

[Paintor]

You have a bad collapsible lifter that is not hydraulicly pumping back up.

 

The V4 mode collapses 4 cylinders lifters to close valves. You have a bad one that is not staying pumped up to fully operate a valve.

 

Get it to the Dealer ASAP. 

 

Do not tell dealer you get a backfire from AFM disabler. Tell them it backfires when you drive in “M” instead of Drive (also disables AFM)

Edited May 16, 2019 by Paintor

[Huntere]

20 hours ago, JimCost2014 said:

You are very welcome,

 

And sorry, meant to say drive without Range to see how truck acts.

No problem, I will try that too

[Huntere]

On 5/15/2019 at 5:58 PM, 3tspapat said:

Drive it in L mode with 7th gear selected. This will disable start/stop and also AFM. If you still have the same issues, then it's not the Range, but rather the set up that you have. 

eAssists loves to stay in V4 mode.

 

I currently have 2018 eAssist and with the range noticed some hard shifting. Sent it back to Range for firmware update. But even now noticing shifting has gotten harder. Think it's just time to take it in for the TSB.

I have just tried this without the Range device and it does not seem to backfire, but when I plugged the Range back in, it didn't do anymore backfiring. Interesting

I have also talked to a mechanic that has worked on some of these newer trucks and he has said that the computer inside of the truck needs time to "relearn" since the truck now has a new "code" and is supposed to  change itself to operate smoothly. He said that it may take around 10 drive cycles (when the engine is up to operation temp) to "relearn".

Hopefully it just takes time like he said.

23 hours ago, Paintor said:

You have a bad collapsible lifter that is not hydraulicly pumping back up.

 

The V4 mode collapses 4 cylinders lifters to close valves. You have a bad one that is not staying pumped up to fully operate a valve.

 

Get it to the Dealer ASAP. 

 

Do not tell dealer you get a backfire from AFM disabler. Tell them it backfires when you drive in “M” instead of Drive (also disables AFM)

It may be possible that the lifter had gotten stuck before trying this Range disabler too and when it was plugged in it stayed stuck. After driving a little without the disabler and allowing it to switch back to V4 mode it may have freed that possible stuck lifter, I have plugged the device back in and so far it is running fine with no backfiring. If something gets worse, I'll contact my dealer.

Thank you for the input!

[3tspapat]

Hey that is an interesting observation in regards to vehicle getting used to the range. Driving in L7 before the range did not produce any rough shifts. After installing the Range I did notice some but since i'm not heavy footed it, didn't really think much of it until someone else posted about hardshifting and the Range. In testing that again, I removed the Range and noticed still intermittent hard shifting. Reinstalled and and noticed the same. Currently I've been driving without the Range in L7 and it does seem to be shifting better as time goes on. I'm going to give it a few more weeks and then put the Range back on, and then let that go for a few more weeks. 

 

Will report back later if i can find this thread again. 

[Hillwood]

On 5/15/2019 at 10:25 PM, Paintor said:

You have a bad collapsible lifter that is not hydraulicly pumping back up.

 

The V4 mode collapses 4 cylinders lifters to close valves. You have a bad one that is not staying pumped up to fully operate a valve.

 

Get it to the Dealer ASAP. 

 

Do not tell dealer you get a backfire from AFM disabler. Tell them it backfires when you drive in “M” instead of Drive (also disables AFM)

If there are no codes and the engine is running normal without the Range,  what can the dealer do? Bad lifters should make noise or cause a misfire. 

Edited May 19, 2019 by Hillwood
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[Paintor]

11 hours ago, Hillwood said:

If there are no codes and the engine is running normal without the Range,  what can the dealer do? Bad lifters should make noise or cause a misfire. 

There is a screen filter for the oil on the electronic solenoid that collapses the lifters. Sometimes that is plugged. There is a TSB on it.

 

You essentially have to wait for a failure or code for warranty work.

 

Another Dealer diagnostic is hooking Tech2 to it and seeing the actual oil pressure. Think 19psi is too low and would also cause the issue.