DFM disabler released
- Thread starter 66 Galaxie
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BeyondMyMeans
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Curious why you say up to about 55mph? I am at the tail end of a 2 week family road trip and have been running in L9 on the highways averaging 75mph. Only seems to raise the RPM like 300 or so from just having it in Drive. I'm still getting like 420 miles to the tank (2024 RST PE).
Marky Dissod
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As Marky Dissod stated, there is very little difference between 9th and 10th gear. I mentioned 55 MPH because I found on secondary roads the transmission would shift into 10th somewhere between 50-55 MPH depending on the load. So for folks that want to get the highest fuel economy, they would probably want to get into 10th gear once they fully get on the highway.
You could run the trans in L9 all the time, as mentioned, there it very little ratio change between 9th and 10th. I would say it is closer to 200 RPM as I recall when I was closely monitoring the gear and RPM differences. It is pretty hard to tell when the transmission shifts from 10th to 9th unless you have a scan tool that displays the transmission gear which I had been logging for a while. I have not looked really closed about the overrun clutch as mentioned, probably would hold back a bit more on decel if the case.
You would take a slight hit in MPG, I think I can get close to 500 miles per tank if I pushed it, but for me a vehicle is out of fuel at 1/4 tank, this is the world I live in.
7th gear is 1.00
8th gear is 0.85
9th gear is 0.69
10th gear is 0.64
As mentioned the 4L80/90 4th gear is 0.75, so this is actually between 8th and 9th on the 10 speed.
9th will clearly help offload a lot of the low RPM, high Load that the 10 speed puts on these V8 engines. But the 6.2l TCM holds the gears much longer and loads the engine far more than the 5.3l TCM. Running in L9 might actually save the 6.2l from itself in the long run!
Been having this module in my '23 Z71 Tahoe with 6.2 for about 11 months with no issues until last Tuesday. After morning startup, drove about 5 miles then vehicle throws multiple codes, ABS, charging system, and transmission. Won't go over 45 mph. I'm still under warranty, so call OnStar for tow to dealership. After running diagnostics, some reflashes/ECM updates still having codes. I guess at some point they start looking for loose connections on the ECM and come across this module, remove it and all the codes clear. Not sure if the unit failed or had some OTA update that jacked something up. Being this is my wife's vehicle, and it is not just a simple removal process it now can collect dust on my desk. Unfortunately, I don't believe this module is simple install and forget add-on that will be flawless for the life of the vehicle, I have zero trust in this module.
nick14226
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Thanks for the heads up.
Ideally Range would get this feedback and you’d send the Disabler back for evaluation and report back their findings. If an OTA caused the issue your trust would be restored.
Frankly I don’t think I could drive my Tahoe without it at this point.
Most likely a weak/bad battery. From my understanding, unless things have changed, most manufacturers will not do OTA updates that update propulsion, steering or braking. Most OTA updates are related to Infotainment and OnStar.
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nick14226
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Don't disagree, but it's recommended to remove the disabler prior to an OTA. Believe mostly because it could cause the OTA to fail, but maybe mess with module as well.
The random codes could be a weak battery, but doesn't track if they removed the module and all codes cleared on there own (if that's really the case, battery should be disconnected to when removing installing connectors like that).
Point is, a lot of assumptions/conjecture, would be nice to know if there's actually something wrong with the disabler...
Marky Dissod
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Totally agree. Think of it like this: if you're using the vehicle, the vehicle should PROBABLY use the disabler.
(Yes, I go so far as to recommend removing it when you're not driving it, but that's me.)
If the vehicle is not being used, the vehicle should probably NOT use the disabler.
If the vehicle is being repaired, or otherwise 'addressed', it should NOT use the disabler.
The disabler ... disables ... V4 mode, and A.S.S. if you're lucky.
If the dealer - or any other mechanic, for that matter - is working on your vehicle,
the disabler will not be doing either of those things, so why would you leave it in there?
Range wants me to send the module back, rep said they would probably just replace it. Rep didn't seem to question the validity that my dealer claims the module was the problem, though I'm not too confident they will follow up with me on their findings once they test it.
nick14226
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No, you’ll likely have to follow up with them to find out. Good they’re replacing it for you
Marky Dissod
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You're likely not the only person that does NOT want to hear this, but
the simple answer is to unplug it whenever you or someone that you trust is not using / driving the vehicle - if only to protect it from everyone / everything else.
Module is not likely the problem or cause of the problem. BUT anytime you take the vehicle to the dealer, you should REMOVE the module because often if you have the vehicle in for other service under Warranty, the dealer may choose to update modules for different reasons.
The Range module has been known to interfere with updates, so it is best to remove before service.
I have had my Range module in my 2024 for over a year without problems. My vehicle has never been back to the dealer since purchase and most likely will not be back if I can help it.
The Range module has been known to interfere with updates, so it is best to remove before service.
I have had my Range module in my 2024 for over a year without problems. My vehicle has never been back to the dealer since purchase and most likely will not be back if I can help it.
nick14226
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The 21-up disabler plugs into the ECM behind the driver side fender liner. I don't disagree with what you're saying, but this isn't the easy pop in and out of the OBD port while sitting in the drivers seat.
My Tahoe went to the dealer for a failed high pressure fuel pump and before the tow truck arrive I removed it. But again, not super easy to get to if you're in a jam (especially if you can't crank the wheel all the way to the left).
nick14226, I agree 100% and in my case the vehicle, my wife's Tahoe, took a dump 5 miles after she left home and went into limp mode. She sure as hell isn't going to crawl under the front to pull it and I wasn't anywhere nearby to do it, so it was sent to the dealer as was, disabler inline of ECM.
When I got on Range's website today to get the number to call, I searched around for some documentation regarding removing the module when having the vehicle serviced but didn't come across anything saying specifically to do so. I know a few in this post are saying to do so, if that is the case, where did you find that information?
When I got on Range's website today to get the number to call, I searched around for some documentation regarding removing the module when having the vehicle serviced but didn't come across anything saying specifically to do so. I know a few in this post are saying to do so, if that is the case, where did you find that information?
nick14226
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You mentioned that the problem occurred about 5 minutes after your wife left the house. You indicated there were multiple codes to include ABS, Charging System and Transmission related.
Based on years and year of experience with either weak batteries and/or charging system problems with many of the vehicles built in the last 10-15 years if the charging system has problems and the available vehicle Voltage drops below 12 Volts, as modules fail to properly communicate and the ECM tries to keep the vehicle running, triage starts to happen and modules start to shut down. Usually it starts with higher current draw and less required system like ABS and other systems that are not required for vehicle propulsion.
It takes so much current/Amperage to operate all the systems in these modern vehicles it is crazy and battery/charging system problems can play havoc on everything.
I just do not see the Range module somehow causing the a charging system problem, especially after having it installed for as long as you had it on the vehicle. I do not know fully how the Range module functions, but somehow is spoofs signals to the ECU to keep the DFM from operating and it clearly also spoofs the ASS (Auto Stop/Start) to not operate. I will agree that it is wise not to have the module installed when trying to flash update modules, I would not expect OTA updates to be impacted by the module being installed. Maybe I am wrong about OTA updates, but I guess time will tell with OTA updates being a problem. I can say from my experience it does appear to take longer for the Emission Readiness Monitors to fully set with the Range module installed. I original felt that a few of the Emission Readiness monitors may never set on my vehicle. I contacted Range support with my concern, their blanket answer was to remove the module and drive the vehicle for the Emission Readiness monitors to set before an Emission Inspection. Well it turns out this is not the case, it just seemed to take longer for the Emission Readiness Monitors to set than expected and I have had a few instances where I had cleared codes on the ECM and each time the Emission Readiness Monitors have changed to the Ready state without issue after driving for a while. I have yet to remove the Range module from my vehicle since installing at 274 miles 14 months ago.
I had a BMW X5 that had a cold solder joint in the alternators internal Voltage regulator. When you first started the vehicle the charging system would not function, but if you drove about 1 mile to allow the circuit to warm up a bit, you could shut the engine down and restart it and the charging system would be fine for the entire drive. The stupid thing is you could remove the serpentine belt and the vehicle would never alert you that there was a charging system problem. I luckily for other reasons had been running and UltraGauge and noticed the charging system one day right when it happened.
This problem showed up in Dec or Jan at the coldest time of year and I had no interest in working on the vehicle in the cold so I nursed the problem along for months. Start the vehicle, watch the UltraGauge, no charging, drive about 1 mile, shut vehicle off at a stop sign or traffic light, alternator would then charge for the entire drive cycle.
All was good until one day I had to pick my wife up at the airport. Was waiting in the cell phone lot with the engine off listening to the radio. She arrived and called me, I started the vehicle and headed to the terminal to pick her up, stayed on the phone discussing her trip, forgot to check the UltraGauge. Pick her up at the terminal and head home, with about 5 minutes all hell broke loose! Dash starts popping up messages about ABS, Active Suspension, Traction Control and other things having problems and shutting down. Then I look up at the UltraGauge and I realize what is going on, vehicle Voltage is like 11.5 Volts.
Oh crap moment, I have have to pull over, shut the vehicle off and HOPE is restarts. Well guess what, engine won't crank, I start getting you should get rid of the POS BMW, blah blah blah, I just returned from an international flight blah, blah, blah.
I say hold please, jump out get my battery jumper pack connect to the battery, vehicle fires up, UltraGuage shows alternator is charging, slowly all error messages clear, vehicle operating as normal, wife starts to calm down.
Point is ANYTIME there is some charging related problem with newer vehicles, you have problems. Start with a full and problem battery and charging system test, but also note on these vehicle the alternator is commanded Off by the ECM for fuel economy. GM has been doing this on these truck platforms for over 25 years. My 2005 GMC Yukon has the system that shuts the alternator down while driving.
I really doubt the Range Module had anything to do with your problems. I suspect a battery/charging system related problem because every error you listed points directly back to a charging system issue. It may have been a fluke, one off charging system issue, it could be an intermittent charging system issue that may take some time to show up again. I would personally have the battery and charging system tested and keep a close lookout for anything that is out of the ordinary with how the vehicle starts and while the Range module is out of the vehicle, I would personally turn off the ASS (Auto Stop/Start) system because I would not trust the vehicle electrical system until you can have it tested and even testing it may not find a problem like the one I ran into on my BMW X5.
Good luck.
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jfoj, appreciate your insight and my first thought was also battery or low voltage issue, but it was towed to the dealer and I have to assume they checked the charging system and battery as it was showing the same codes while in service and being diagnosed. Once they saw the module on the ECM, they pulled it and all codes gone. Picked it up on Saturday and module is enroute back to Range for testing/replacement. Tahoe running fine since. In all honesty, for what it does, and the inconvenience it "may" have caused is just not worth re-installing, especially on my wife's daily driver. I will definitely update this thread if these codes reappear or similar issues arise.
