Engine cut out while climbing mountain pass

[xtrailman]

It was an interior light I believe. That, or some of the interior electronics (stereo?) managed to stay on. The battery was totally drained. I was gone for about 3 hours and got back to a dead car.

A radio or interior light shouldn't flatten a battery in 3 hours.

 

[CX-SV]

A radio or interior light shouldn't flatten a battery in 3 hours.

Agreed. Could have been a defective battery. I've experienced that once in a new car.

 

[mclark999]

Particleman - I sometimes test/dry the brakes near the top of a big hill in wet conditions to make sure they are dry and ready for use on the way down. If you do that with while the gas pedal is engaged the CX-5 computer is programmed to shut the engine down until you come to a full stop and turn on dash error lights. This is to eliminate the possibility that you hit the gas by accident and are really trying to stop the car. If you happened to have done the brakes while pressing the gas at the top of your hill, the car stopped and lit up the lights as designed and requires you to stop the engine to clear the lights. You can dry the brakes just take you foot off the gas when you do. Don't ever brake with your left foot while engaging the gas with your right or the computer gets real confused and requires you to come to a full stop to restore power...

Is this documented by Mazda? Seems very dangerous. Wouldn't be hard to bump the brake while you have your foot on the gas.

 

[particleman]

This just happened to me again, except this time the AT and engine lights came on too, and stayed on after I restarted. Very frustrating. This car is going back to the dealer ASAP. I wasn't even in manual mode, and i was on a very gradual climb. I hope this is just a software reflash issue as mentioned in an earlier post.

 

[GAXIBM]

Is this documented by Mazda? Seems very dangerous. Wouldn't be hard to bump the brake while you have your foot on the gas.

It is in the theory section of the service manual. They judge the problem of people not realizing their foot is pressing both pedals at the same time and saying they can't stop a run away car as a big legal risk, which it is... Maybe a minor bump would not set it off, I have not tried it...

 

[ta240]

It is in the theory section of the service manual. They judge the problem of people not realizing their foot is pressing both pedals at the same time and saying they can't stop a run away car as a big legal risk, which it is... Maybe a minor bump would not set it off, I have not tried it...

shouldn't it just cut power to the engine while both pedals are pressed and return it once you let go of the brake? I know everyone is paranoid after the Toyota/Lexus thing but that seems like overdoing it for a solution.

 

[MikeM.]

Are all your tires the same diameter? Just a lb. or two difference in air pressure can really mess up an AWD. This could cause the drive train to get too hot. Are your tires the same size as OEM? A larger diameter can mess up the gearing causing the car to shift at the wrong times. The dealer should be able to read the codes and see what actually happened. Does this happen with added load (such as stuff strapped to the roof or towing a trailer)?

I've run my CX-5 really hard a number of times (although not at 10,000 feet) and never had a hiccup so I'm just wondering what the difference might be.

 

[GAXIBM]

shouldn't it just cut power to the engine while both pedals are pressed and return it once you let go of the brake? I know everyone is paranoid after the Toyota/Lexus thing but that seems like overdoing it for a solution.

I remember reading that the lights stay on until the engine is turned off which resets the lights. You may not have to stop the engine to get power back but I think you have to stop the car(?) Ask a lawyer if it is overkill, my guess is no.

 

[ta240]

Last night while driving I tried pressing on the brake while also pressing on the gas and nothing odd happened. I was pressing pretty solidly on both. No lights came on at all, the engine didn't cut out, it may have cut power some as the brakes were winning the battle or the brakes might just be good enough to do that, but as soon as I let off on the brake it accelerated like normal.

 

[ta240]

You may not have to stop the engine to get power back but I think you have to stop the car(?)

my guess is if you actually had to stop the car and restart it to get any power back it would open up a lot more liability than continuing to accelerate with both pedals pressed. Too many situations where that could leave you in the path of oncoming cars.

All the override systems I've heard of just cut engine power if the brake is pressed.

 

[IHeartGroceries]

This thread has turned into a real mishmash. But there is no way a few solenoids presents a heavier electrical load on the charging system than actually starting the car, especially a cold start.

 

[GAXIBM]

Last night while driving I tried pressing on the brake while also pressing on the gas and nothing odd happened. I was pressing pretty solidly on both. No lights came on at all, the engine didn't cut out, it may have cut power some as the brakes were winning the battle or the brakes might just be good enough to do that, but as soon as I let off on the brake it accelerated like normal.

I don't know - maybe the theory in the book was not programmed or maybe it changed after the book was released. I will try it on mine which is a very early build.

 

[mclark999]

I don't know - maybe the theory in the book was not programmed or maybe it changed after the book was released. I will try it on mine which is a very early build.

I also tried hitting the brakes while accelerating both half throttle and full throttle. The brakes slowed the car down, but no effect on engine programming.

 

[CX-SV]

I also tried hitting the brakes while accelerating both half throttle and full throttle. The brakes slowed the car down, but no effect on engine programming.

Exactly as expected.

 

[particleman]

For those that are still interested…

My dealer did a software flash, and I have yet to experience the problem again. The software flash is a “temporary fix” according to Mazda and something more long-term is in development. My dealer tech said that they aren’t really allowed to mess with the CX-5s technology systems without Mazda USA’s direction. Right before Christmas, I called Mazda Consumer Affairs and gave them my whole story, and they said they’d get back to me after the holidays. So far, no call-back. The fact that one dealer tech said my battery was the issue, and the other tech said it was a software issue, tells me someone doesn’t know what’s going on, or no one knows what is actually going on, and the software update was a shot in the dark. The first tech’s claim that “Mazdas are battery hungry” and that the alternator does not fully charge he battery makes no sense. Either way, the problem has not repeated since the software update, so I’m content for now.

To answer the other questions that have come up:

No, I did not hit the gas and brake pedals at the same time. I was only hitting the gas pedal.
Yes, the tires are all the same diameter (they are the original tires). They may have been a pound or two off from each other, I don’t know. I didn’t check the pressure before getting in the car. It was very cold, and we were at 8-10,000 ft, so maybe that will change the air pressure. Not sure.

 

[CX-SV]

Thanks for the report particleman.

Most of us know that a couple of pounds variation in tire pressure and touching brakes and gas at same time would not cause a problem this serious.

I'm still puzzled as to why the battery died...

 

[popeyecahn]

Thanks for the report particleman.

I'm still puzzled as to why the battery died...

Hatch compartment light? I've noticed that the hatch, if not properly shut on my CX-5 the cargo area light will stay on. I don't know if this light is on the same auto off circuit as the rest though, but add in a cargo cover and who would know if it shut off? I did because when i first noticed this I didn't have the cover yet. Now add in cold weather and maybe the battery was adversely affected?

 

[CX-SV]

Hatch compartment light? I've noticed that the hatch, if not properly shut on my CX-5 the cargo area light will stay on. I don't know if this light is on the same auto off circuit as the rest though, but add in a cargo cover and who would know if it shut off? I did because when i first noticed this I didn't have the cover yet. Now add in cold weather and maybe the battery was adversely affected?

Per owners manual (assuming it actually works as described below):

NOTE
l Battery saver
If any door or the liftgate is left opened, the
light goes out after about 30 minutes to
save the battery.
l The operation of the illuminated entry
system can be changed.
Refer to Personalization Features on page
9-8

 

[GAXIBM]

I also tried hitting the brakes while accelerating both half throttle and full throttle. The brakes slowed the car down, but no effect on engine programming.

Going at 35 mph I jammed the brakes and gas on my early GT and the car stopped with the engine rpm low not pulling hard, I released the brake and it paused a few seconds and then started pulling hard. It appeared to me that the brake and throttle at the same time reduced the throttle until I releaced the brake. I did not get any error lights.

 

[thisman]

I experienced a similar problem - and it turned out that the bolts holding the cables to the battery needed to be tightened a bit. I doubt that's your problem (and that's probably what they checked first thing), but I thought it would be worthwhile mentioning.