AFM Disable Options

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

TerryP

TYF Newbie
Joined
Aug 29, 2024
Posts
3
Reaction score
1
Quality. The cheaper ones either may not have proper coding and may struggle for priority on the CAN bus, or they may be made with cheaper IC's and flash and will fail prematurely.

That's strictly from my consumer products design experience, so consider that general advice, not specific to these devices.

That said, after the nightmare I went through with this episode, I wish I had just found the $500 to do the HP Tuner out of the gate instead of running that stupid dongle for 2 years, LOL.

Still, the dongle does "work", you just have to accept the SMOG complications and potential premature failures.
Thanks for the reply, Kwing. So there are future implications to using the dongle?? I have a problem with using the OBD port for a nefarious purpose but if it solves the problem....Right now at 84K miles on this recently purchased Yukon I hear a lifter tapping at cold idle. Exhaust note sounds like a weak cylinder but not a dead miss. Performance does not appear to suffer. Question: Thinking of changing from the 0W-20 to 10W-30 semi synthetic with oil change intervals at 5,000 instead of current 7,000. Think that will help?
 

West 1

Member
Joined
Jan 20, 2023
Posts
69
Reaction score
97
As instructed already, find someone local that can enter your computer and turn off the AFM. They will have a laptop with a program installed. I had to pay $100 to buy a license to use the GM software. It only licenses you to work on one vehicle but it allowed entry to the OEM computer to shut this off. I used a local guy that was familiar with he GM Software.

I agree with others, if you are plugging your filter screen you have other issues. Change the oil more frequently.
 
Joined
Apr 11, 2018
Posts
7,124
Reaction score
14,365
Location
St. Louis
How do you like the DiabloSport Intune I3? I'm thinking about getting it to disable my DoD on my 2011.
It's fine. I really haven't used it much on the Yukon since getting it and uploading the performance tune and turning off DOD/AFM and the speed limiters. It's been a couple years actually and might be time to break it out and play around with some other things, like shift points and pressures or remove some of the torque management between shifts. I like that it has the ability to save tune files to it from a PC and flash it to the vehicle, so if you get a custom tune made they can just email you the file.

If none of that interests you, then I would just get a BTDieselworks AutoSync and one of their split OBD port cables. You can disable AFM just with a tick of the DIC buttons. The Autosync enables a lot of features using the DIC and the cruise control and mirror D pad buttons. It will also flash the BCM if you purchase the features online, then it downloads the file and flashes it, but even without custom BCM options, it allows you to enable many, many things. It also connects to my home wifi when parked in the garage or driveway and checks/downloads firmware updates, which are released pretty regularly
 

opfor2

Full Access Member
Joined
Mar 29, 2023
Posts
259
Reaction score
200
Location
Riverside County, CA
It's fine. I really haven't used it much on the Yukon since getting it and uploading the performance tune and turning off DOD/AFM and the speed limiters. It's been a couple years actually and might be time to break it out and play around with some other things, like shift points and pressures or remove some of the torque management between shifts. I like that it has the ability to save tune files to it from a PC and flash it to the vehicle, so if you get a custom tune made they can just email you the file.

If none of that interests you, then I would just get a BTDieselworks AutoSync and one of their split OBD port cables. You can disable AFM just with a tick of the DIC buttons. The Autosync enables a lot of features using the DIC and the cruise control and mirror D pad buttons. It will also flash the BCM if you purchase the features online, then it downloads the file and flashes it, but even without custom BCM options, it allows you to enable many, many things. It also connects to my home wifi when parked in the garage or driveway and checks/downloads firmware updates, which are released pretty regularly
I'm going to get the DiabloSport Intune I3 this weekend.
 
OP
OP
K

Kwing

Member
Joined
Nov 18, 2017
Posts
75
Reaction score
51
Thanks for the reply, Kwing. So there are future implications to using the dongle?? I have a problem with using the OBD port for a nefarious purpose but if it solves the problem....Right now at 84K miles on this recently purchased Yukon I hear a lifter tapping at cold idle. Exhaust note sounds like a weak cylinder but not a dead miss. Performance does not appear to suffer. Question: Thinking of changing from the 0W-20 to 10W-30 semi synthetic with oil change intervals at 5,000 instead of current 7,000. Think that will help?
As far as the dongle and future implications... yes. The way the dongle works is by basically sending a command over the CAN bus telling the AFM not to engage. Because the ECU is telling it to engage, then the dongle tells it not to, the ECU recognised it's command was not followed and responds in kind by throwing a fault code and illuminating the MIL. Because this would be an undesirable behavior for something that is supposed to "fix" a problem, the dongle therefore constantly erases the fault codes on the ECU so the MIL isn't on.

The problem is, at least in states like Arizona, the way they SMOG test all 1996 and newer OBDII equipped vehicles is by simply hooking up to the OBDII port, verifying no codes, verifying the check engine light works, and verifying all the systems are "ready". With the dongle constantly resetting the error codes, the computer is never "ready". So to pass SMOG in such a state, you have to remove the dongle and the let the ECU reach the "ready" stage, which can take several weeks. During that time, obviously the AFM is active again without the dongle in.

If you're just disabling it to disable it, it's a very small risk of the AFM failing during that period. If, however, like me, you had a radiator blow out and cause a severe overheating issue that left char deposits in your engine, and you remove the mesh filter at the oil pressure sensor because the char keeps blocking it, then removing the dongle becomes almost certainly fatal for the AFM lifters :).

Furthermore, because it is constantly resetting the ECU, other codes that may indicate other issues are effectively hidden. I had 4 pop up once the dongle was gone :).

The performance tuners allow you to simply tell the ECU to stop turning AFM on at all. If it never calls for it, it can't recognize that it didn't respond. Problem solved for good until and unless your ECU is reprogrammed to factory spec.

But again, that's $500 vs $150 or less. The level of risk in your circumstance is something you have to evaluate. I left myself with no choice, though, so don't be me, LOL.

I can't help you with the oil question, unfortunately. I live in Arizona, where 9 months out of the year we fall into the temperature range where 20W/50 is recommended, so I just run 20W/50 full synthetic all year round, which only slightly increases the oil pressure during the "winter". I haven't used anything below 10W/30 in so many years I've almost forgotten they exist, LOL.
 

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
3,241
Reaction score
4,024
just a reminder, if you can do without the truck for a few days, you can mail off the ecm and have afm disabled in the tune for 50$ last I checked. it's not as good as buying hptuners, but it is cheaper and better than the dongles to me.
 
Joined
Apr 11, 2018
Posts
7,124
Reaction score
14,365
Location
St. Louis
As far as the dongle and future implications... yes. The way the dongle works is by basically sending a command over the CAN bus telling the AFM not to engage. Because the ECU is telling it to engage, then the dongle tells it not to, the ECU recognised it's command was not followed and responds in kind by throwing a fault code and illuminating the MIL. Because this would be an undesirable behavior for something that is supposed to "fix" a problem, the dongle therefore constantly erases the fault codes on the ECU so the MIL isn't on.

The problem is, at least in states like Arizona, the way they SMOG test all 1996 and newer OBDII equipped vehicles is by simply hooking up to the OBDII port, verifying no codes, verifying the check engine light works, and verifying all the systems are "ready". With the dongle constantly resetting the error codes, the computer is never "ready". So to pass SMOG in such a state, you have to remove the dongle and the let the ECU reach the "ready" stage, which can take several weeks. During that time, obviously the AFM is active again without the dongle in.

If you're just disabling it to disable it, it's a very small risk of the AFM failing during that period. If, however, like me, you had a radiator blow out and cause a severe overheating issue that left char deposits in your engine, and you remove the mesh filter at the oil pressure sensor because the char keeps blocking it, then removing the dongle becomes almost certainly fatal for the AFM lifters :).

Furthermore, because it is constantly resetting the ECU, other codes that may indicate other issues are effectively hidden. I had 4 pop up once the dongle was gone :).

The performance tuners allow you to simply tell the ECU to stop turning AFM on at all. If it never calls for it, it can't recognize that it didn't respond. Problem solved for good until and unless your ECU is reprogrammed to factory spec.

But again, that's $500 vs $150 or less. The level of risk in your circumstance is something you have to evaluate. I left myself with no choice, though, so don't be me, LOL.

I can't help you with the oil question, unfortunately. I live in Arizona, where 9 months out of the year we fall into the temperature range where 20W/50 is recommended, so I just run 20W/50 full synthetic all year round, which only slightly increases the oil pressure during the "winter". I haven't used anything below 10W/30 in so many years I've almost forgotten they exist, LOL.
Very informative post on how the dongle disables the AFM.

I'd be curious as to how the Btdieselworks AutoSync does it and if it uses the same process.

I might re-enable AFM in my tune with the Diablo intune i3 I use and disable the AFM using the AutoSync on its splitter cable and after about a week of driving checking the readiness monitors with the scan tool plugged into the other port.
 
Joined
Apr 11, 2018
Posts
7,124
Reaction score
14,365
Location
St. Louis
I just re-enabled AFM in the tune and also checked the readiness monitors and they're showing as "incomplete", as they should after flashing the tune.

I have the AutoSync set to disable AFM.

Now I just have to drive it for a few days and check the readiness monitors and see if they ever become "ready"
 

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
3,241
Reaction score
4,024
using hptuners to disable mine and all the monitors have shown pasted before.

I'm a bit curious about this auto sync. does it flash the ecm or do you have to leave it plugged in all the time? what about their bcm mods, same question I guess. can you make changes to the tune? or is it a dongle that stays plugged in and requests things over can?

be careful activating afm after it's been off a while. if you hear the lifter get stuck, ****** get it released and turned back off
 

mikez71

Full Access Member
Joined
Mar 9, 2023
Posts
1,513
Reaction score
1,784
If you get the BCM tuning for autosync, the autosync is used to flash your BCM.
BCM tuning mostly deals with light configurations, door locks, extended accessory power.

Otherwise, the autosync needs to stay plugged in for the afm disable, high idle, flashers, remote windows, dtc reader, camera etc.
 
Top