The technology you’re describing already exists . . . and has for a long time . . . on certain vehicles
Creature features will be limited, if a low charging system voltage is detected with the engine running
Climate control, heated seats, blower motor, etc. will be limited, or not available, for instance.
I think the micro-controllers that form the heart of the car’s ECM run on a considerably lower voltage than 12 volts. More like in the 3-6 volt range. On my Corolla, the ECM runs on 5 volts. There’s a voltage regulator which reduces the battery voltage to what the ECM requires. That’s why those 9 volt battery powered gadgets are able to power up the ECM and prevent data loss during engine battery removal.
This particular example below works on anywhere from a 1.8 to 6 volt power supply, but is recommended by the manufacturer to be powered from between 1.8 to 3.6 volts, probably to keep the temperature down and for best rejection of electrical noise on the power bus.
The computers in cars certainly do have the ability to have Immense computing power…so almost anything is possible in regards to how the system deals with varying voltages and what is or is not available as a creature comfort standpoint. Hell ALL of our cell phones probably exceed the computing power of the Space Shuttle at this point in time…y’know?
Blackbird
Zach thanks for the blog. My Tahoe is doing the same thing. Jerking at low speeds and when breaking. Im also from Miami. I read your blog and immediately did what what you said with the tcm battery fuse. I drove it after for about 15 and everything felt ok. Hopefully tomorrow morning it stays like that. How were you able to read those codes, if you don’t mind me asking?
To be honest I never got it resolved. But what I really think it was was the torque converter. That’s badiclly the clutch for the car. You can get a new refurbished one made by Daaco for $100 an have it installed for like 300 bc they gave to drop the transmission. This is ultimately what I figured it has to be, can’t really be anything else. If your cars acting like the clutch is being “operated by 12-year-old” and jerking when you take off and brake, I can’t imagine what else it would be. Let me know if you ever get it fixed
So the problem came back? I’ve read in other blogs that the computer that controls the v4 to v8. I’m guessing it’s called the pcu or something like that is what causes that. Chevy hasn’t perfected it and it is happening in the newer models as well.
No it’s not the computer. I had mine reflashed. It always comes back. If ur smart ull hit it hard the first time and just replace the torque converter. Have a reputable transmission shop do it.
I even had my computer reprogrammed by Black bear nothing changed. It’s the torque converter.
Also did u buy ur car used it ur the only owner?
The idea being that the blades or "vanes " of the impeller insude torque converter have become bent over time and when the point comes the impeller starts to spin and forces the fluid across the torque converter and esserialy pushes itself of against the “stator” inside the torque converter, which then starts to spin and match the same speed as the impeller is turning, and this is essentially what the the action would be of the clutch “engaging”. This is where I think the problem lies. So it results in a sensation of “popping” the clutch instead of coming off it steadily when ur driving a manual transmission and ur controlling the clutch release. That why I said it feels like someone is operating the clutch isn’t doing it correctly. That’s what it felt like I’m my car. FWIW, I also had the transmission computer actually replaced and that dos nothing for it. I think it was the mechanics inside the actual torque converter so replace that.
UFZach i also just started having this issue jerking at low speeds during acceleration and also while stopping with no codes coming up.I tried the fuse and no change to the issue. I see now that you are saying it’s the torque converter. Just wanted to verify before bringing it to a transmission shop.
2 year old thread so you might not get a reply. But you do not tell the shop what to do or repair. You give them the symptoms and then decide if you want to have them do what they recommend.
Jeremy I wouldn’t listen to Volvo. Did you by the car new or used? Have you ever changed tire size
Jeremy, I would listen to VOLVO_V70, you don’t tell them what to fix, you tell them what it’s doing and let them figure out what’s wrong.
I’ve got a 2015 Tahoe that is experience similar jerking (92k miles), but only when downshifting into what I assume is 1st when doing a gradual deceleration (normal braking to a stoplight, for example). I don’t notice it in hard deceleration, nor at any other shift points. It will also trip if you accelerate to about 18-20mph and take your foot off the gas and let it deceleration naturally. At 15mph (like clockwork), you feel a very jerky deceleration, like you’ve manually shifted incorrectly.
I saw this post and immediately went to go look for the BCM fuse in the manual, but it appears there are several (labeled BCM 1-8). I also look for TCM battery, but the diagram shows two: “Transmission Control Module Ignition” and “Engine Control Module/Transmission Control Module.”
Either of these sound like winners?