D7-AFM?

[John_E_Ringo]

Hey everyone, I recently picked up a used 2018 E-assist Sierra having no idea this was a “hybrid”. Now that I’m wanting to eliminate the v4 and start/stop stuff, all the message boards are recommending tunes (which I can’t seem to find who does this) or driving in D7. Can someone tell me what the heck is “D7” and how do I drive in it?

 

thanks for the help. 
 

John

Edited June 2, 2024 by John_E_Ringo

[rav3]

What year is your truck?

D7 is 7th gear in the L range. Put it in L & u can shift up or down using the "+/-" lever. You must have an 8 speed.

You can disable both 4V & start/stop with a 'Range' device plugged into OBDII port. Google it.

[John_E_Ringo]

It’s a 2018 and I’ve looked into the range device but have heard mixed reviews about it and harder shifting issues. Are these really concerns?

[rav3]

I have a '17 LTZ 5.3 w/six speed & install a Range 4 years ago when I bought it & haven't had any issues with it. In NC where emissions inspection is required, I have to remove it for about 50 miles to pass test emissions part.

[Buckwild27]

1 hour ago, John_E_Ringo said:

It’s a 2018 and I’ve looked into the range device but have heard mixed reviews about it and harder shifting issues. Are these really concerns?

If you don't want to spend the money and don't mind the check engine light being on you can just unplug the vacuum sensor on the brake booster line. That sensor is what tells the truck it's ok to go into v4 mode. No other issues will pop up if you do this. And it will be in v8 mode full time. 

Edited June 2, 2024 by Homewrecker007

[rav3]

47 minutes ago, Homewrecker007 said:

If you don't want to spend the money and don't mind the check engine light being on you can just unplug the vacuum sensor on the brake booster line. That sensor is what tells the truck it's ok to go into v4 mode. No other issues will pop up if you do this. And it will be in v8 mode full time. 

@homewreaker......didn't know that. However, I don't think it will stop his 'start/stop' function. I believe u can buy the Range to do both.

[Buckwild27]

8 minutes ago, rav3 said:

@homewreaker......didn't know that. However, I don't think it will stop his 'start/stop' function. I believe u can buy the Range to do both.

That I have no experience with. My trucks didn't come with that function.