2019 CX-9 wouldn't start and bunch of malfunctions

:
2019 CX-9 Signature
Hi everyone,

Sorry English writing is not my strongest skill.

Rough day today. Spent my afternoon detailing the 2019 CX-9 (bought at Nov 2018 now 37k miles just passed warranty) and in the end the car wouldn't start. Everything was normal before the wash. It was throwing a bunch of malfunctions including SCBS/Keyless System/Cameras/Sensors etc I couldn't remember all (And one says Refill the tank but I have 4/5 full tank). Basically most of the dashboard was lighted up. It did try to crank for half a sec and stopped. I used Torque Pro app and BT ODB2 adapter and no fault code found. I'm suspecting the battery is dead but car is only less than 2.5 years old. We do daily 40 minutes each way commute and some short trips.

Here's the list of my diagnosis I've tried / things I did / possibilities.
  • Fortin Evo-One with Maz3 harness was installed 2 days ago by myself and was working flawlessly. Disconnected the harness and restored to factory set up still no go.
  • I placed the key fob in the cup holder with the car off for the duration of my wash which was about 3-4 hours this afternoon. Was about 50'F nice weather.
  • Inspected the fuses in the panel all looked good.
  • I used damp cloth to wipe down under the hood briefly. It was normal routine I do for car wash all the time.
  • Cleaned and put back cabin filter and air filter.
  • Tried both key fob and replaced both key fob batteries. At one point Low Key fob battery warning was displayed.
  • Disconnected battery (-) terminal and waited an hour. Reconnected, locked then unlocked the car with remote. Get in the car still get Keyless System Malfunction and couldn't start.
  • I have a dashcam plugged into the passenger footwell usb. Been using it this way since new and no issue.
  • Accidentally engaged the ebrake during interior cleaning and left it on.
  • Brake feels super firm but brake light does lit up.
  • Honk doesn't work.
  • Ebrake light was flashing sometimes.
  • Could not open the tail lift gate with like double beep.
  • Sprayed the underside of the car to clean off dirt and salt.
  • Serviced at dealership last month / 1000 miles ago and the battery status on their report was green.

Now about 6 hours later I tried to start it again it won't even crank. And some new weird things like Door button wouldn't work, mirror doesn't fold, remote sometimes work sometimes not. Had to use physical key to lock the car once.

Like I said I'm suspecting the battery is dead. Could it be the ~2 hours i was cleaning the interior and keep having the doors open and close with the key fob in the cup holder cause the dome lights to drain my battery? Or could it be the Fortin Evo-One draining? I don't have a battery tender/charger or multi-meter nor I couldn't try to jump start with the car head in my narrow driveway. My best bet is to take the battery to Autozone for testing. If the battery is indeed dead I will get a Duralast Platinum (or any recommendation?) and see if it will fix it. My last option is tow it to the nearest dealership if changing battery doesn't help.

Could I have damaged the electrical system during my car wash? I've been wash the same way for years with my past BMW and this CX9.

TLDR: Car won't start and throwing dozens of malfunction messages after routine car wash by myself. Suspecting the battery and seeking advice.
 
:
2021 CX-9 Sig
:
2014 CX-5 GT
That does sound strange but could be the battery. I would replace it and see, and if that does not work, it sounds like a dealer visit is in order.
 
Battery is done. You ran it down too far. You can try to charge for 8 hours using a slow charger but you may have done damage already and may be too weak. Get a new one from Costco for $79. Do not get ripped off at a dealer for a battery and do not buy one from auto parts store for double the price!
 
First step is to charge or replace the battery. Battery chargers aren't that expensive, but if the battery is fully drained, smart chargers won’t start. In which case you would have to boost the car first, let the engine run for a little while before Shutting it off and putting the charger on. Your battery may have been damaged from being depleted too much, but it might still be fine as well once fully charged, you never know.

so either get a charger, long boost cable, a battery booster pack, or a brand new battery. Once your battery is charged or new, then you can diagnose for parasitic load, but chances are the 2 hour wash drained it enough to not start, and then the multiple attempts afterwards kept draining it more and more. Batteries regain a little bit of charge when they sit for a while, so it is normal for functions to come back or be different the next day, but usually not enough to restart the car.
 
:
2019 CX-9 Signature
Thanks guys I will get a new battery and see how it goes later. If it's the battery it really threw me off with the Christmas dashboard.
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
Here's the list of my diagnosis I've tried / things I did / possibilities.
  • I placed the key fob in the cup holder with the car off for the duration of my wash which was about 3-4 hours this afternoon. Was about 50'F nice weather.
  • I have a dashcam plugged into the passenger footwell usb. Been using it this way since new and no issue.

I think these are the main causes, specifically the key fob in close proximity. With the keyfob in the cup holder, the proximity sensors for door locking/push button start etc. are constantly detecting the fob. Because of this, there is a constant drain on the battery, and if left long enough, it can run the battery down. Next time you detail or work on the car, put the key down maybe 5-6 feet away to ensure it isn't in the range of the proximity sensors.

I have run the battery down to empty a couple of times on my 2018. My suggestion would be to first try to trickle charge the battery using something like a Battery Tender. You should be able to get more life out of it, though eventually you will need to get a new battery. I'm still on my original and plan to replace it before winter 2021, just to be safe.
 
:
2019 CX-9 Signature
I think these are the main causes, specifically the key fob in close proximity. With the keyfob in the cup holder, the proximity sensors for door locking/push button start etc. are constantly detecting the fob. Because of this, there is a constant drain on the battery, and if left long enough, it can run the battery down. Next time you detail or work on the car, put the key down maybe 5-6 feet away to ensure it isn't in the range of the proximity sensors.

I have run the battery down to empty a couple of times on my 2018. My suggestion would be to first try to trickle charge the battery using something like a Battery Tender. You should be able to get more life out of it, though eventually you will need to get a new battery. I'm still on my original and plan to replace it before winter 2021, just to be safe.

I think that's mostly the case plus the dome lights were on and off from opening doors. Dashcam wasn't powered on when the car is off.
 
:
2019 CX-9 Signature
Battery is done. You ran it down too far. You can try to charge for 8 hours using a slow charger but you may have done damage already and may be too weak. Get a new one from Costco for $79. Do not get ripped off at a dealer for a battery and do not buy one from auto parts store for double the price!
Unfortunately I have to go with Autozone Duralast Gold at double the price. Called my local Costco they don't have it in stock.
 
:
Mazda CX-9 Grand Touring 2016
In the last "Consumer Reports" car battery test Walmart batteries got good ratings. Their Everstart Maxx (640 cca) is $99. The battery needed is Group 35 size, available everywhere except holland's Costco this week. (O'Reilly's Super Start Extreme, same cca, same 3 year warranty is $169!)
 
:
2010 CX-9 GT
I switched from Autozone to Walmart batteries when Autozone reduced their warrantee. In Florida, no battery seems to last more than 2-3 years anyway.
 
:
Winnipeg Canada
:
2017 CX-9 GT
When I first got my 2017 my plan was to install a 24f AGM battery. Someone here has documented the conversion. But now I'm thinking the 35 group might be good enough but definitely will stick with agm style battery.

Also, get a multimeter. Very handy tool. And I just picked up one of these on sale: https://www.canadiantire.ca/en/pdp/motomaster-1200a-lithium-jump-starter-power-bank-0112063p.html

Just keep that in the trunk. In our winters, it can be life and death if you're in a remote area and your car can't start.
 
:
2019 CX-9 Signature
When I first got my 2017 my plan was to install a 24f AGM battery. Someone here has documented the conversion. But now I'm thinking the 35 group might be good enough but definitely will stick with agm style battery.

Also, get a multimeter. Very handy tool. And I just picked up one of these on sale: https://www.canadiantire.ca/en/pdp/motomaster-1200a-lithium-jump-starter-power-bank-0112063p.html

Just keep that in the trunk. In our winters, it can be life and death if you're in a remote area and your car can't start.
What advantage does AGM offer? I just got a multi meter and a portable jump starter in case.
 
:
Winnipeg Canada
:
2017 CX-9 GT
There's multiple reasons you'd want it for a car. One is they tend to deliver current faster and more reliably even in cold weather. They charge faster, making them better for those who regularly drive short trips (like I drive my kids to school which is less than 1km).

The main reason however is their deep-cycle capability, or cycle-rating, which means you can run them down to the point where you can't start your car, and then charge them back up again with little damage (keep doing this however and eventually you will kill it, but a lead-acid would die well before an AGM). Regular lead-acid batteries are damaged severely when they are fully or partially drained, but AGM batteries a lot less so. Also, you can leave them unused for longer periods without worrying about them discharding. GEL batteries are actually even better at this but they also cost more (Optima). But the fact is that led/acid batteries are just really bad in this department, you really need to keep them charged all the time and can't let them sit for too long as they just naturally loose charge. So I think it's worth the extra cost. I used to run Optima batteries, but I find there's little reason to spend that much with AGM batteries being almost as good.

Another advantage is that you don't get that green crud all over your battery terminals.

 
Last edited:
:
‘17 CX9 Sig/ ‘19 6
There's multiple reasons you'd want it for a car. One is they tend to deliver current faster and more reliably even in cold weather. They charge faster, making them better for those who regularly drive short trips (like I drive my kids to school which is less than 1km).

The main reason however is their deep-cycle capability, or cycle-rating, which means you can run them down to the point where you can't start your car, and then charge them back up again with little damage (keep doing this however and eventually you will kill it, but a lead-acid would die well before an AGM). Regular lead-acid batteries are damaged severely when they are fully or partially drained, but AGM batteries a lot less so. Also, you can leave them unused for longer periods without worrying about them discharding. GEL batteries are actually even better at this but they also cost more (Optima). But the fact is that led/acid batteries are just really bad in this department, you really need to keep them charged all the time and can't let them sit for too long as they just naturally loose charge. So I think it's worth the extra cost. I used to run Optima batteries, but I find there's little reason to spend that much with AGM batteries being almost as good.

Another advantage is that you don't get that green crud all over your battery terminals.

Totally agree with this...years ago I replaced my Volvo’s lead acid OEM battery with an AGM and it performed really well esp no problems on extreme cold start ups and frequent short trips. I’d definitely replace my Mazdas’ OEM batteries with AGM again!