2017 Mazda CX-5 dash lights flash when trying to start.

[Dborch41]

My son was trying to start his Mazda last night and the only thing that happened was the dash lights would rapidly click on and off but no engine crank. He pushed the start button again but they wouldn't stop flashing. He had to disconnect the negative battery terminal to get it to stop. I did some research and apparently a low battery is the prime culprit, even though it's only a year old. What seems unique in this case is that the only way to stop the chaos was to disconnect the battery.

I'll be going to his house tomorrow morning armed with my jumper pack, multimeter and code scanner to see what's up. If anyone has any advice on what to look for in particular it would be greatly appreciated.

 

[clinebarger]

Low voltage from a discharged battery most likely.

 

[researcher]

My son was trying to start his Mazda last night and the only thing that happened was the dash lights would rapidly click on and off but no engine crank. He pushed the start button again but they wouldn't stop flashing. He had to disconnect the negative battery terminal to get it to stop. I did some research and apparently a low battery is the prime culprit, even though it's only a year old. What seems unique in this case is that the only way to stop the chaos was to disconnect the battery.

I'll be going to his house tomorrow morning armed with my jumper pack, multimeter and code scanner to see what's up. If anyone has any advice on what to look for in particular it would be greatly appreciated.

had this happen to my friend's 16 CX-5, it was my fault though.. Kept the car in the "on" position when plugging in the obd scanner, I forgot to hook up the charger while I did that!

But.. the symptoms were the exact same as your son's 17 CX-5! Dash lights came on, no crank, then eventually the lights didn't even come on! Pulled it out and charged it back up, but my ancel tester showed it wasn't that healthy anyway, got a new one, no more issues..

be interesting to test the battery and see what the results are, but you're on the right track to fix it!

 

[50yr Street Mech]

Low voltage on battery. Car sat too long or defective battery. If the car sat long, could be parasitic draws from car computers. They never shut down. May need to put car on a battery tender if it sits long periods.

 

[Propflux01]

Mazdas are known to get electrically wonky on batteries that are anything less than top-notch and fully charged.

 

[vwmaniaman]

That is the battery. Had the same problem on our CX5. Go get a battery and don't waste your time testing.

 

[KrisZ]

If the car is equipped with keyless entry, don’t keep the keys close to the entrance or the garage because it will keep several of the car modules awake all the time and drain the battery this way.

I think it’s one of the main causes of early battery failures these days. People think that once the car is off and locked, everything electrical is shut down, which is not the case. Most modules go to “sleep” aka low power mode after about 20 minutes. But if the proximity key is too close, they will never go to the low power mode.

Basically if you can lock and unlock the vehicle with your proximity key from the storage location, it is too close to the vehicle and it will keep it awake.

 

[50yr Street Mech]

Friggin computers ....Recently read most vehicles have 40 or more in them..That's 40 or more problems to deal with if/ when they act up. Totally unnecessary to have that many computers to run a gasoline or diesel powered vehicle. I can just imagine how many computers are in an electric vehicle. Yeah, I can see if they were putting out 65 miles per gallon of gas, but they're not. Then they're worth the aggravation. My 03' Solara 4 banger has only 3 computers and gets 32 mpg on the highway. Never a problem changin a battery in that thing. Oh. I'm sorry, you have to re-set the clock. Takes 15 seconds. Even the radio holds it's pre-sets.

 

[dogememe]

Friggin computers ....Recently read most vehicles have 40 or more in them..That's 40 or more problems to deal with if/ when they act up. Totally unnecessary to have that many computers to run a gasoline or diesel powered vehicle. I can just imagine how many computers are in an electric vehicle. Yeah, I can see if they were putting out 65 miles per gallon of gas, but they're not. Then they're worth the aggravation.

I get what you're saying, but modern vehicles do give you a ton of features, tech, and safety that older vehicles simply don't have. It's hard to compare vehicles across brands and ICE vs EV but I asked Grok to compare a Rivian, Cybertruck, and Corolla, and got this answer:

"Rivian's zonal architecture, as implemented in its second-generation R1 vehicles, uses a total of 7 electronic control units (ECUs). Tesla's Etherloop system in the Cybertruck employs 3 domain controller ECUs. In contrast, a modern gas-powered vehicle like the Toyota Corolla—representing a typical compact sedan without advanced electrification or autonomy features—would have significantly more, generally in the range of 30-50 ECUs for lower-end models, though exact counts for specific trims aren't publicly detailed. This highlights how zonal and loop-based architectures in EVs dramatically reduce complexity compared to traditional domain-based systems in ICE vehicles, which often require dozens of dedicated controllers for functions like engine management, infotainment, safety systems, and body controls."

Comparing slightly more similar vehicles like a 2024 Equinox EV to a 2024 Model Y, Grok claims the GM product has 10-15 ECUs while the Tesla has 3-5. So even within EVs, it makes a big difference one model to the next.

 

[50yr Street Mech]

Yeah, and all of Amazon's Rivian's are parked in a lot somewhere because the charge they hold can't support a day's worth of deliveries. Where I live in NY, Amazon rents gasoline vans from Budget, Penske, and whoever else they can scramble up to get the deliveries out. I saw one Amazon Rivian at my house, that's it. Then I asked all the next drivers' " where are the Rivians ? ". Oh, they can't hold a charge for a days run of deliveries, so Amazon just rents now. But I understand what you're talking about, my mistake on the amount of computers for EV's. They are useless in my eyes anyway. Gets too cold, you can't charge them. Can only drive X amount of miles. There is not a single charging station in the town I live in. Build the infrastructure 1st, then sell the cars.... That's like selling gasoline powered cars, without any gas stations to fill the tank.

 

[Dborch41]

Update:
You were all correct, the battery only had 9 volts and the car came alive with the booster pack. Took it back to Walmart for a warranty return, the clerk gave us a "we'll see about that" smirk as she hooked up the load tester. Her expression was short-lived as apparently that battery was a goner, so the replacement was no charge...so to speak.

Needless to say the boy was quite happy with the easy, free fix. Now we just have to figure out what is up with his Jeep Cherokee, apparently it needs a proxy alignment. I just ordered the gadget needed for that onerous task, but that's another post.