So yesterday I disabled AFM/DOD (ie: V4 mode) on my car because it was starting to bug me. I had long argued it was unobtrusive, but the sound was actually what was bugging me.

Anyway, in looking at the parameters that control DOD, I was wonder what you cold do to disable AFM -without- modifying the actual calibration.

Below you can see the set of paramters that must be true for V4 mode to kick in. What I'm wonder is if you were on the CAN bus, what could you broadcast that might cause it to never kick in AFM?

The Range module must do something similar, because I assume they do not modify the tune (hope not, anyway).

My first guess would be: "What if you broadcast the CAN packet saying that oil temp is 60F. Will that cause problems, and will it disable AFM?"

Clearly the car will also be continually sending CAN packets with the correct (actual) oil temp, so I don't know if the AFM code looks at the last oil temp or rules out AFM because it say -any- recent parameters that were out of range.

I don't know how V8 run time is tracked, but if you continually sent a packet saying "V8 mode has been running for 1 second", that should also prevent it. These are total guesses though.

Any bright ideas? What could you set out of range that would disable AFM without upsetting anything else?

 

OK, I'll guess with ya' I'd be tempted to set the Disable RPM to 650.

Did I win a prize?

I seem to recall disabling CAGs by lying about RPMs so I'm going with RPM for $100

Elmer

 

No, I want to do it without changing the tune. In other words, nothing in that table can change. So I'd have to broadcast on the bus some bogus information that caused AFM not to activate but without messing anything else up.

 

Come on, I drive a convertible with chrome wheels and I'm the only non-waxer? Must be other people with -some- level of experience on this stuff :-)

I found the AFM inhibit PIDs, that's likely a start:

GM.AFM=1,4387
GM.AFMINHIB1=1,4389
GM.AFMINHIB2=1,4390
GM.AFMINHIBH1=1,4391
GM.AFMINHIBH2=1,4392
GM.AFMINHIBH3=1,4393
GM.AFMINHIBH4=1,4394
GM.AFMINHIBH5=1,4395
GM.AFMINHIBH6=1,4396
GM.AFMINHIBH7=1,4397
GM.AFMINHIBH8=1,4398
GM.AFMTRANS=1,4400

 

Dave,

For what it is worth I found this quote from Adam who is with Range while I was looking into the Range module last year. Don't know if it helps but add it to your data:

"We do not reflash the ECU. We plug into the OBDII port and send a command that tells the vehicle to stay in V8 mode. We don't fool it with false signals, etc. This is a factory command and we figured out how to issue it. The device leaves no trace nor log in the ECU, and once removed, is completely invisible. "

 

Thanks! It could be as simple as broadcasting one of the AFMINHIB pids, I really don't know. Glad to hear they don't monkey with false signals. There are a number of Camaro threads/videos about it setting a CEL though, which is what made me guess it was false signals (but they're clear they don't do that).

Wish I had a full list of known GM pids and what they do. I'm sort of fascinated by it all but not fascinated enough to put in the months/years it takes to bootstrap my knowledge from scratch! Since I'm not going to run out and make one, I'd rather just know how it's done.

They say it's patented, so they shouldn't be too concerned with secrecy, since you have to document how it works for the patent anyway...

 

Maybe something here can get you pointed in the right direction

https://google.com/patents/US8584647

 

How about sending a signal that constantly shows it has maxed out on 4V time?

 

I have been running the Range module in my 2015 for over 35k miles..(my car has 52K..its my daily...and i can't stop driving it) its worked great...i never see V4 mode...and dealer did warranty work to replace the torque converter and did not detect it. It has never thrown a CEL or code. Fuel Economy is barely affected.

It works in real time and does not change your ECU just like you are envisioning.

 

Yeah, but it's not powered by Tiger sweat and voodoo, I want to know how it works, what they're doing. I'm not going to make one, they're a couple of hundred bucks at best and it'd cost me 5X that to make one plus my own time... but I'm a curious fellow.

There's a problem to be solved and they already solved it and I'd like to know what they did. I guess I could get a Y-cable and log it with Vehicle Spy but I'm not -that- curious.

I'm curious enough to BS about it but not to break out the scope... but still curious.

 

FWIW: I have a 2017 Z06 and got CEL every time I used the Range AFM module. Ironically, I asked them before ordering it if it would work on my year as their site doesnt mention it being compatible. They claimed it works fine and I even sent it in to them to upgrade it to the latest model (in case mine wasnt) and I still had issues with it. I ended up sending it back.

If you figure this out, let me know as I really hate V4 mode but dont want to tune the car while its in warranty.

 

hahaha. I thought I'd go get this for this cheap ***. Went to the website, WOOF!. I;m not that curious either.

 

I'd be happy to pay Range thier asking price for the device if they would just make it work correctly on the Vette. No dead batteries and no CELs. Even if it required a bit more complicated install than a simple plug in. IE ground and power connections.

 

I'm going to revisit mine and turn it back to Enable, but set the "Min VSS" to 54. That way I'll still be able to get AFM on highway cruise but it won't kick in every time I coast down a hill in town.

I'll let you know how that goes when I try it!

 

Look forward to hearing about your success.