2020 CX-5 mysterious battery draw

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
The SSP C2 says the Power LiftGate (PLG) control unit may not switch to the power saving mode which will drain the battery due to “improper control logic”. So nobody is curious about why this PLG control unit issue only happens on 2020 CX-5 (and CX-9) whereas the power liftgate feature actually featured since 2017 CX-5? The firmware / software in PLG control unit should be the same, or Mazda did some update on PLG control unit software for 2020 MY but unfortunately screeed up the logic on power saving mode?
 
:
Texas
:
'19 MX-5, '20 CX-5
As a programmer, my guess is that a software change was made to fix a bug or improve performance and it actually introduced a new problem as an unintended consequence. Or, it could have been an existing issue all along and a change elsewhere in the vehicle was sending a signal that sometimes prevented the PLG unit from going to sleep and it may have been cheaper to update the software in the PLG unit than update or replace the component that was "revealing" this bug.
 
Last edited:

Freedom55

2020 AWD GS Montreal Canada
Compared to other CX-5 competitors, I think this is minor! Hyundai/Kia engine fire, CR-V 1.5T oil dilution with gas and low heater output in cold climate, Subaru blown head gasket/excessive oil burning, Nissan CVT/transfer case, etc.

I tried the CR-V after the CX-5 3 weeks ago but decided on the CX-5. I do short trips in cold climate so the CR-V was out of the question. Too expensive (no real end of year discount and sluggish from a start) otherwise, a nice vehicle, too bad.
 
:
Texas
:
'19 MX-5, '20 CX-5
After having four Hondas with multiple problems in the last few years including one that would have legally qualified as a lemon had I not got rid of it, I remain very impressed with my MX-5 after a year (zero problems) and CX-5 (PLG unit caused dead battery). The CX-5 has also had the fewest rattles of any of the 30+ automobiles I've owned. All of them generally started out quiet, but tiny annoying noises (that I'm very sensitive to) always started within a few thousand miles. The CX-5, so far, has been an impressive exception. I still look forward to driving my Mazdas. I can't think of a brand I've been more satisfied with. Given my history of frequent trades, I may not own the CX-5 more than year or two, but I'm willing to bet it will be remembered as one of the most problem-free and enjoyable automobiles I've owned so far.
 

Freedom55

2020 AWD GS Montreal Canada
After having four Hondas with multiple problems in the last few years including one that would have legally qualified as a lemon had I not got rid of it, I remain very impressed with my MX-5 after a year (zero problems) and CX-5 (PLG unit caused dead battery). The CX-5 has also had the fewest rattles of any of the 30+ automobiles I've owned. All of them generally started out quiet, but tiny annoying noises (that I'm very sensitive to) always started within a few thousand miles. The CX-5, so far, has been an impressive exception. I still look forward to driving my Mazdas. I can't think of a brand I've been more satisfied with. Given my history of frequent trades, I may not own the CX-5 more than year or two, but I'm willing to bet it will be remembered as one of the most problem-free and enjoyable automobiles I've owned so far.
That's good to know! Here North of the border, it was 0°F this morning and my new to me (6,000 miles demo) CX-5 had no squeaks or rattles driving on rough roads; I'm also impressed how the doors close with a reassuring thump and all body panels are perfectly aligned. It provided enough heat but it took some time before the temp gauge reached normal; however, I'm sure it's better than in a CR-V...I've read that to solve the oil dilution by gas in cold climate they reprogrammed the ECM to allow the engine to get warmer at the expense of the occupants comfort. Many loyal Honda customers are not happy; there's a class action lawsuit about their 1.5L turbo. My wife had a 2008 Civic coupe and it was the most reliable car she ever got, looks like things have changed.

I had a trouble free 2014 Murano and stupid me, I traded in for a 2017.5 to get all the latest goodies but it was a lemon. No way I was getting another Nissan even if the 2021 Rogue is a vast improvement; "once burned twice shy" as the saying goes (or something like that English is my second language)!
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
That's good to know! Here North of the border, it was 0°F this morning and my new to me (6,000 miles demo) CX-5 had no squeaks or rattles driving on rough roads; I'm also impressed how the doors close with a reassuring thump and all body panels are perfectly aligned. It provided enough heat but it took some time before the temp gauge reached normal; however, I'm sure it's better than in a CR-V...I've read that to solve the oil dilution by gas in cold climate they reprogrammed the ECM to allow the engine to get warmer at the expense of the occupants comfort. Many loyal Honda customers are not happy; there's a class action lawsuit about their 1.5L turbo. My wife had a 2008 Civic coupe and it was the most reliable car she ever got, looks like things have changed.

I had a trouble free 2014 Murano and stupid me, I traded in for a 2017.5 to get all the latest goodies but it was a lemon. No way I was getting another Nissan even if the 2021 Rogue is a vast improvement; "once burned twice shy" as the saying goes (or something like that English is my second language)!
Do you have a 2020 CX-5? In what trim level?

Looks like Mazda finally resolved the vibration issue in cold weather due to the inferior new liquid engine mounts used on gen-2 CX-5.
 

Freedom55

2020 AWD GS Montreal Canada
Do you have a 2020 CX-5? In what trim level?

Looks like Mazda finally resolved the vibration issue in cold weather due to the inferior new liquid engine mounts used on gen-2 CX-5.
I have a Canadian 2020 CX-5 GS which is similar to Touring in the U.S. At idle in drive once warmed up, it's so smooth and quiet you would think the engine is not running!
 
I was one of the early posters on this thread, and just update for all, I'm in Canada too, and got my Special Service Program (SSP) letter a week or so ago, and took the car in this morning to replace the power liftgate control module.

My dealer informed me that they tested my battery, and gave me a new battery as well, as they tested and it was weak likely due to draining from the PLG module. So that's pretty good, a brand new battery as well! My car was delivered new March 2020, so it was manufactured during the Sep 3, 2019 to March 28, 2020 period which had the faulty PLG module. Even before I heard there was this issue, I was in the habit of plugging a battery tender if the car wasn't going to be driven for a couple of days, so that may have helped me avoid a completely dead battery.

I don't view this positively rather than negatively. As others have said this is a relatively minor and easy fix. And I'm sure the PLG module is made a third-party supplier. I think Mazda handled it very well, pinpointing the problem fairly quickly (it can be hard to pinpoint these types of problems) and then doing the right thing by doing a special service program.
 
Does anyone have a remote start that is having problems since this has been done?

I have an aftermarket remote start that uses the factory fob (press lock-unlock-lock to start). If I remote start it, I'm locked out of the car. The only way to get in is to open the hatch and reach in with the remote, which will shut off the car. Seems unrelated, but it worked fine before and the only thing I can see that changed is that the dealer did this update on 9/8/20 while it was in for an oil change.

I tested it without the remote start and the same problem exists-- when the car is running, if it is locked and the keys are outside you can't get in. This is not easy to do. You can't lock it while its running from the outside. You can't lock it with the interior button and close the door. The only way I could simulate it was to open the window, put the fob inside through the window, press the interior lock button, then take the fob out.

Does anyone have a 2020 CX5 that hasn't had the update? Can you try to do the same test and see what happens?
 
:
2020 CX-5 AWD
… it worked fine before and the only thing I can see that changed is that the dealer did this update on 9/8/20 while it was in for an oil change....
Oil changes are well known to cause all sorts of problems.

But seriously, IMO the aftermarket remote start unit makes any comparison to our non-modified vehicles fairly meaningless. And no, I have not read any other report like what you posted.

I don't know if you're aware that a portion of the locking functionality can be changed by the owner, by following specific steps which are outlined in the Mazda documentation. I have not studied these modification options in detail, because there's nothing I feel needs to be changed with the way the system works now. However, given that your system has now become messed up, perhaps this capability might be a way for you to make things operate the way they used to on your vehicle.
 
Oil changes are well known to cause all sorts of problems.

But seriously, IMO the aftermarket remote start unit makes any comparison to our non-modified vehicles fairly meaningless. And no, I have not read any other report like what you posted.

I don't know if you're aware that a portion of the locking functionality can be changed by the owner, by following specific steps which are outlined in the Mazda documentation. I have not studied these modification options in detail, because there's nothing I feel needs to be changed with the way the system works now. However, given that your system has now become messed up, perhaps this capability might be a way for you to make things operate the way they used to on your vehicle.
The remote start doesn't make it meaningless at all. While it may be the reason that I noticed it in the first place, the behavior that I suspect changed-- the ability to unlock the door with the car running and the fob outside of the car-- can be be duplicated without using the remote start at all. This is why I asked if someone who hasn't had the update can verify how it works.

I am very much aware that there are some aspects of the locking that can be changed... but this is not one of the them.
 
:
CX5 GT
If it helps you, I cannot unlock or lock the car from outside if its running. The fob lock unlock function just doesnt work if engine is running. Thats on 2018. It has always bugged me that I cant lock the car with the fob if I leave it running. but it is what it is.

By the way, you can unlock it with the mechanical key in the fob. :)

So my guess would be in your case it was overridden by the remote start addon somehow, if unlock was operational on a running engine before. And may be (speculating) if a firmware update was done, this feature needs to be re-enabled from the remote start system again.
 
Does anyone know if this problem persists in the 2021 model? I have a 2021 CX-5 Signature that was purchased in December 2020. This afternoon, I tried to start my car and found that the battery was completely dead. Nothing was left on or open. I drive the car every week. The car will be inspected on Monday by the dealership.
 
Hi,
New member here looking for some insights into a mysterious electrical draw that’s causing my battery to go dead overnight on a new 2020 CX 5 Signature. It seems to happen when I pull the car into the garage at night. No lights or accessories are left on, nothing, such as charger, is plugged in and the car is turned completely off not left in accessories mode. The car has been at the dealer for a week. They couldn’t find any abnormal electrical draw and the battery was in normal condition. Apparently the 2020s have some type of wifi modem for future functionality and the service manager thought it might be seeing my house WiFi (recently installed a new / stronger house WiFi router) but they checked and the device on the CX 5 is in the correct inactive mode. They were telling me they couldn’t find anything. I pressed them to keep looking and then they found a recent service bulletin about a potential issue with a rear left gate electronic that might draw more power than normal when the car is off but they were talking miliamps and I am uncertain that extra amount is enough to drain the battery overnight. The left gate electronic part is on back order. I also asked the dealer to test parking it with objects in front and behind to assess whether the parking sensors are staying active after it’s turned off. It’s been a big downer on a new top of the line Signature we spent $40k on. Anyone heard of this type of issue and what the solution might be? Thanks guys.
I had this issue with a brand new CX5 in 2020 that died overnight even when no electronics were on. Dealer was initially clueless, researched this forum and found the rear liftgate issue and relevant bulletin. My 2020 CX5 model production code matched the bulletin and only after I spoon fed them all the info they agreed and replaced my rear liftgate module. Completely fixed the issue.

Responding from a phone but if you research this forum you should find a chain with the relevant info.

Good luck.