Crazy Electrical and Start Up Issues plus Warning Lights

J

jwal97

2021 Mazda CX-5 grand Touring Reserve. 60,000 miles. Have had for 2 years. Started getting issues with start button at first. Would have to press it s couple times to get it to work. Happened intermittently. Became more frequent. Would have to do all sorts of weird combinations (different almost every time) to get the car to start. From pressing the start button and waiting a few seconds before engaging the brake, to sometimes having to engage the brake first. Sometimes I get the green light on the start button sometimes not. Didn't matter because sometimes it would start either way. Then on occasion after it starting fine, I could not shut it of. Then I would turn my headlights on (or even off sometimes) and that would stop the engine, without me even touching the start button! Got new battery. Seemed to help for a while, though it would still be quirky. Replaced key fob batteries as well. Doesn't seem to be the brake pedal switch either.

Rode it for a few days with having to wait a few seconds before engaging brake pedal and start button (in other words I'd press the start button for accessory and then press the pedal and button a few seconds later) and it would start fine. Always ran fine once started as well, but then I started getting all sorts of random warning lights and messages almost always different every time. Now I can't start it anymore. Got it started once and it was stuck in park. Any ideas what this could be? Trying not to have to take it to dealer since the nearest one is 2 hours away.
 
I would recheck the battery connections... Tight? Corrosion? Voltage on the new battery is?

You could get FORscan and a Bluetooth dongle to plug in the OBDii diagnostic port and find all the codes it's storing. That may help in diagnosing the problem.
 
HyFlyer said:
I would recheck the battery connections... Tight? Corrosion? Voltage on the new battery is?

You could get FORscan and a Bluetooth dongle to plug in the OBDii diagnostic port and find all the codes it's storing. That may help in diagnosing the problem.
Click to expand...
Thanks for the suggestions. I will recheck all of that.
 
My best guess is that the BCM (body control module) is going crazy. (all sorts of strange issues)
Search the TSBs. I recall that there is a TSB on BCM.
Yours is out of B2B warranty.

Get a multimeter to make sure your battery is at reasonable voltage.
(12.5-12.6v after parking for a while)
 
jwal97 said:
2021 Mazda CX-5 grand Touring Reserve. 60,000 miles. Have had for 2 years. Started getting issues with start button at first. Would have to press it s couple times to get it to work. Happened intermittently. Became more frequent. Would have to do all sorts of weird combinations (different almost every time) to get the car to start. From pressing the start button and waiting a few seconds before engaging the brake, to sometimes having to engage the brake first. Sometimes I get the green light on the start button sometimes not. Didn't matter because sometimes it would start either way. Then on occasion after it starting fine, I could not shut it of. Then I would turn my headlights on (or even off sometimes) and that would stop the engine, without me even touching the start button! Got new battery. Seemed to help for a while, though it would still be quirky. Replaced key fob batteries as well. Doesn't seem to be the brake pedal switch either.

Rode it for a few days with having to wait a few seconds before engaging brake pedal and start button (in other words I'd press the start button for accessory and then press the pedal and button a few seconds later) and it would start fine. Always ran fine once started as well, but then I started getting all sorts of random warning lights and messages almost always different every time. Now I can't start it anymore. Got it started once and it was stuck in park. Any ideas what this could be? Trying not to have to take it to dealer since the nearest one is 2 hours away.
Click to expand...

I'm not following you here. You speak of sometimes pressing the start button and then engaging the brakes afterward and then sometimes the other way around?

The brake HAS to be applied FIRST every time in order to start the car.

Apply brake, press Start button. No other way to do it and have it start.

As for the car being stuck in Park. You didn't park on a hill without using the parking brake, did you?

Who replaced the battery? Did you check the condition of the terminals and the clamps?
 
All of the strange things happening does seem like it is very likely a battery problem. New or not it could be discharged somehow and it doesnt' matter if the battery is new when something could be running the battery down after a period of time. The only way to tell is find out the battery voltage using a meter, not looking at the label.

I also wonder if you could have something wrong with the parking brake transmission switch, or parked on hill and caused the parking pawl on the transmission to 'lock'.

What has the weather been like where you are? How many miles/hours per day/week/month do you operate the car and under what conditions: hwy cruising, stop and go, light traffic..... etc?

Do you have accessories installed that could drain the battery? Do you park in a heated garage?

jwal97 said:
2021 Mazda CX-5 grand Touring Reserve. 60,000 miles. Have had for 2 years. Started getting issues with start button at first.
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jwal97 said:
Then I would turn my headlights on (or even off sometimes) and that would stop the engine, without me even touching the start button! Got new battery. Seemed to help for a while, though it would still be quirky. Replaced key fob batteries as well. Doesn't seem to be the brake pedal switch either. ??????

Rode it for a few days with having to wait a few seconds before engaging brake pedal and start button (in other words I'd press the start button for accessory and then press the pedal and button a few seconds later) and it would start fine. Always ran fine once started as well, but then I started getting all sorts of random warning lights and messages almost always different every time. Now I can't start it anymore. Got it started once and it was stuck in park. Any ideas what this could be? Trying not to have to take it to dealer since the nearest one is 2 hours away.
Click to expand...
 
Conrad 16.5 said:
I'm not following you here. You speak of sometimes pressing the start button and then engaging the brakes afterward and then sometimes the other way around?

The brake HAS to be applied FIRST every time in order to start the car.

Apply brake, press Start button. No other way to do it and have it start.

As for the car being stuck in Park. You didn't park on a hill without using the parking brake, did you?

Who replaced the battery? Did you check the condition of the terminals and the clamps?
Click to expand...
That’s what I’m saying. It doesn’t always start the way It’s supposed to. Sometimes the ONLY way to get it to start is to press the start button first. So yes, while there shouldn’t be any other way to start it, it’s different almost every time. It’s like I have to figure out the mystery combination of things to do, to get it to start (or stop again when it’s running) evening turning the lights on, or off, or to auto. Sometimes I can get it to start, but the last several times I tried it, nothing worked. And no, I wasn’t parked on a hill. Luckily, at the moment, I’m parked in my garage. Thanks for the advice and the input though. I am going to get the battery and everything else rechecked as well.
 
I usually only use the car for a few hours each day. About 10 miles of highway driving back-and-forth, and more stop and go traffic driving in between. Sometimes I don’t use the car for a day or two. Kept in the garage always. But not heated. This first started in the fall, and then stopped for a while, then started when we had a cold snap and snow for a few days, and I was stuck at home, not driving it. That was when the battery was replaced, then it started working better for a while, with a few quirks here and there, but I was able to drive it fine for a couple weeks, but to get it started, as I said, I had to find the right “combination“ sometimes. Then I got sick last week, and was literally bedridden for a few days, and didn’t drive it. And that’s when the latest problem started happening. But this is the first time I couldn’t get it out of park. I did manage to do it with the screwdriver stuck in the manual override button. But of course didn’t want to drive it that way. Has been warmer weather here though. Nights in the 40s, and days in the 50s or 60s.
 
HyFlyer said:
Do you have multi meter you can check your battery voltage? Those short drives may not be charging things up enough. You may be a candidate for a battery charger at home.
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Yep, I think a lot of cars these days have accessories or whatever that tend to use juice and can slowly run a battery down.
Rule of thumb it takes three times as long to recharge a battery as it took to discharge it, which is why short drives never really get the battery fully charged.

Overnite with a $20 battery maintainer/charger or practically any type of charger once a week, at least in the winter, is what I try for.
 
ceric said:
My best guess is that the BCM (body control module) is going crazy. (all sorts of strange issues)
Search the TSBs. I recall that there is a TSB on BCM.
Yours is out of B2B warranty.

Get a multimeter to make sure your battery is at reasonable voltage.
(12.5-12.6v after parking for a while)
Click to expand...
Batery voltage is 12.5. I searched the TSBs. Couldn't find anything on the BCM. So if it is a bad BCM, what are my options? Can it be reset, and will that clear any issues?
 
jwal97 said:
Batery voltage is 12.5. I searched the TSBs. Couldn't find anything on the BCM. So if it is a bad BCM, what are my options? Can it be reset, and will that clear any issues?
Click to expand...

What's the voltage reading while the engine is running? If the alternator is charging properly the reading should be more than 14vdc.
 
Is it possible that the battery cables were ever attached the wrong way and something was fried? Someone did that here not too long ago.
 
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