This is a very common problem apparently with no solution. I have searched all over the Acura forums. Earlier models had the infamous HFL parasitic draw which actually killed the battery in a couple days but this problem was solved by 2008. In my case, I keep getting a Replace Battery message even though my battery and alternator are good. Just to rule it out, I disconnected the HFL module and checked for parasitic draw. Everything ok. Pretty sure that if a solution existed it would be available on an Acura forum, but I thought I would ask here just in case. Acura says it is a software glitch. Thx for your help.
2010 MDX Replace Battery Message
- Thread starter artbuc
- Start date
How old is that battery? Sometimes everything checks out and the battery is still faulty, not all battery's deficiencies can be measured.
Less than 1 year…deluxe Deka. Battery is strong. Bogus BMS messages have plagued this vintage MDX from the very beginning. In the early days, Acura replaced batteries automatically, often telling customers it was the only thing they could do while waiting for Honda to develop a fix. New batteries never solved the problem. There were several distinct problems that often got all mixed together. Many had legitimate dead batteries from parasitic drains, many really did have bad battery sensors, but many (like yours truly) simply got Replace Battery messages when nothing was wrong with the battery or charging circuit. Honda did come up with a software update which worked for a short time then the bogus messages reappeared. I realize posting here is a real long shot but thought I would give it a try.
Just a crazy question... When BMW implemented battery monitoring in the mid-2000s, there was a registration process where you need to tell the vehicle that you replaced the battery. This required a capable scanner/laptop/app+dongle or whatever. There are about a dozen ways to skin that cat.
It makes sense to me that any battery health monitoring system would need something similar to work its best. Does Honda/Acura have something similar? And if so was it done when you replaced the battery?
The BMW system knows, and flags, parasitic drains. It will shut down the circuit branch to avoid running the battery dead and pop a warning "increased battery discharge while stopped" to tell the driver that there's an issue. There's also a "Charge battery" warning if the SoC is low but everything seems healthy and a plug in charge is needed. I've also seen "Replace battery" when the system feels that the battery's capacity is too diminished and it's lifetime is used up. In the owner community there is rampant misunderstanding of the different messages and they are all lumped into 'needs a new battery' and lots of batteries are unnecessarily purchased before moving on the to actual problem
It makes sense to me that any battery health monitoring system would need something similar to work its best. Does Honda/Acura have something similar? And if so was it done when you replaced the battery?
The BMW system knows, and flags, parasitic drains. It will shut down the circuit branch to avoid running the battery dead and pop a warning "increased battery discharge while stopped" to tell the driver that there's an issue. There's also a "Charge battery" warning if the SoC is low but everything seems healthy and a plug in charge is needed. I've also seen "Replace battery" when the system feels that the battery's capacity is too diminished and it's lifetime is used up. In the owner community there is rampant misunderstanding of the different messages and they are all lumped into 'needs a new battery' and lots of batteries are unnecessarily purchased before moving on the to actual problem
Craig, I did find a reference to new battery registration for later models but not for 2010. But, I do not know for sure the answer to your very good question.
Edit: Just checked FSM. No reference to registration. Just says disconnect neg first and reconnect pos first. FSM implies this is necessary to preserve stored data. Don’t know what sequence I used but I will disconnect/reconnect the specified way for kicks and giggles.
Edit: Just checked FSM. No reference to registration. Just says disconnect neg first and reconnect pos first. FSM implies this is necessary to preserve stored data. Don’t know what sequence I used but I will disconnect/reconnect the specified way for kicks and giggles.
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The disconnect/reconnect order is strictly to prevent accidents while the work is underway. When you disconnect the negative, the vehicle body is no longer a ground relative to the positive terminal. As you are using tools on the positive terminal (which comes next) if you make contact between tool and body you have not shorted out the battery through the tool. That's it. All that the modules in the car "see" is that they lost power, regardless of the order of disconnect.
Good luck with your research!
Yep, I also concluded it is safety related. Found a 30 page thread on an Odyssey forum similar to a 20 page thread on an MDX forum. Same problem…no solution. In the early 2010’s, rumors circulated that Acura was working on a software fix. There is a TSB to reflash the battery sensor but could not find anyone say it solved their problem. My conclusion - this is a nuisance message which comes and goes. It is part of the car’s character. Wonder how much I will have to drop price in a private sale? Potential buyers will be understandably skeptical.
